{"id":2635,"date":"2025-03-24T08:46:53","date_gmt":"2025-03-23T23:46:53","guid":{"rendered":"https:\/\/dexall.co.jp\/articles\/?p=2635"},"modified":"2025-03-24T08:47:22","modified_gmt":"2025-03-23T23:47:22","slug":"laravel-left-join%e3%81%ae%e5%ae%8c%e5%85%a8%e3%82%ac%e3%82%a4%e3%83%89%ef%bc%9a%e5%9f%ba%e7%a4%8e%e3%81%8b%e3%82%89%e5%ae%9f%e8%b7%b5%e3%81%be%e3%81%a7%e8%a7%a3%e8%aa%ac%e3%81%99%e3%82%8b7%e3%81%a4","status":"publish","type":"post","link":"https:\/\/dexall.co.jp\/articles\/?p=2635","title":{"rendered":"Laravel LEFT JOIN\u306e\u5b8c\u5168\u30ac\u30a4\u30c9\uff1a\u57fa\u790e\u304b\u3089\u5b9f\u8df5\u307e\u3067\u89e3\u8aac\u3059\u308b7\u3064\u306e\u91cd\u8981\u30dd\u30a4\u30f3\u30c8"},"content":{"rendered":"\n<div class=\"toc\"><br \/>\n<b>Warning<\/b>:  Undefined array key \"is_admin\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>116<\/b><br \/>\n<br \/>\n<b>Warning<\/b>:  Undefined array key \"is_category_top\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>121<\/b><br \/>\n<br \/>\n<b>Warning<\/b>:  Undefined array key \"is_top\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>128<\/b><br \/>\n    <div id=\"toc_container\" class=\"sgb-toc--bullets js-smooth-scroll\" data-dialog-title=\"\u76ee\u6b21\">\n      <p class=\"toc_title\">\u76ee\u6b21 <\/p>\n      <ul class=\"toc_list\">  <li class=\"first\">    <a href=\"#i-0\">LEFT JOIN\u306e\u57fa\u790e\u6982\u5ff5<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-1\">LEFT JOIN\u3068INNER JOIN\u306e\u9055\u3044\u3092\u56f3\u89e3\u3067\u7406\u89e3\u3059\u308b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-3\">\u306a\u305cLaravel\u3067LEFT JOIN\u304c\u91cd\u8981\u306a\u306e\u304b<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-4\">Laravel\u3067\u306eLEFT JOIN\u5b9f\u88c5\u65b9\u6cd5<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-5\">\u57fa\u672c\u7684\u306a\u69cb\u6587\u3068\u30af\u30a8\u30ea\u30d3\u30eb\u30c0\u30fc\u306e\u4f7f\u3044\u65b9<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-8\">\u8907\u6570\u30c6\u30fc\u30d6\u30eb\u3092\u7d50\u5408\u3059\u308b\u9ad8\u5ea6\u306a\u624b\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-13\">\u5b9f\u8df5\u7684\u306aLEFT JOIN\u306e\u6d3b\u7528\u30b7\u30fc\u30f3<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-14\">\u5b58\u5728\u3057\u306a\u3044\u30c7\u30fc\u30bf\u3082\u542b\u3081\u305f\u96c6\u8a08\u30ec\u30dd\u30fc\u30c8\u306e\u4f5c\u6210\u65b9\u6cd5<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-17\">\u95a2\u9023\u30c7\u30fc\u30bf\u306e\u6709\u7121\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u52b9\u7387\u7684\u306a\u65b9\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-21\">LEFT JOIN\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6700\u9069\u5316<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-22\">\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u9069\u5207\u306a\u8a2d\u5b9a\u65b9\u6cd5<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-25\">N+1\u554f\u984c\u3092\u56de\u907f\u3059\u308b\u305f\u3081\u306e\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-30\">LEFT JOIN\u3067\u3088\u304f\u3042\u308b\u30a8\u30e9\u30fc\u3068\u305d\u306e\u89e3\u6c7a\u6cd5<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-31\">\u30ab\u30e9\u30e0\u540d\u306e\u885d\u7a81\u3092\u9632\u3050\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-34\">NULL\u5024\u306e\u9069\u5207\u306a\u51e6\u7406\u65b9\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-39\">LEFT JOIN\u3092\u4f7f\u7528\u3057\u305f\u5b9f\u88c5\u4f8b<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-40\">EC\u30b5\u30a4\u30c8\u306e\u5728\u5eab\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u3067\u306e\u6d3b\u7528\u4f8b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-43\">\u30d6\u30ed\u30b0\u8a18\u4e8b\u3068\u30b3\u30e1\u30f3\u30c8\u306e\u95a2\u9023\u4ed8\u3051\u5b9f\u88c5<\/a>      <\/li>    <\/ul>  <\/li>  <li class=\"last\">    <a href=\"#i-45\">LEFT JOIN\u306e\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-46\">\u30b5\u30d6\u30af\u30a8\u30ea\u3068LEFT JOIN\u306e\u7d44\u307f\u5408\u308f\u305b\u65b9<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-49\">Eloquent\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3068\u306e\u4f75\u7528\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>    <\/ul>  <\/li><\/ul>\n      <a href=\"#\" class=\"sgb-toc-button js-toc-button\" rel=\"nofollow\" data-open-dialog=\"true\"><i class=\"fa fa-list\"><\/i><span class=\"sgb-toc-button__text\">\u76ee\u6b21\u3078<\/span><\/a>\n    <\/div><\/div><h2 class=\"wp-block-heading\" id=\"i-0\">LEFT JOIN\u306e\u57fa\u790e\u6982\u5ff5<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-1\">LEFT JOIN\u3068INNER JOIN\u306e\u9055\u3044\u3092\u56f3\u89e3\u3067\u7406\u89e3\u3059\u308b<\/h3>\n\n\n\n<p>\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u64cd\u4f5c\u306b\u304a\u3044\u3066\u3001\u30c6\u30fc\u30d6\u30eb\u7d50\u5408\u306f\u975e\u5e38\u306b\u91cd\u8981\u306a\u6a5f\u80fd\u3067\u3059\u3002\u7279\u306bLEFT JOIN\u306f\u3001\u30c7\u30fc\u30bf\u306e\u6b20\u640d\u3084\u95a2\u9023\u4ed8\u3051\u3089\u308c\u3066\u3044\u306a\u3044\u30ec\u30b3\u30fc\u30c9\u3092\u6271\u3046\u969b\u306b\u5fc5\u9808\u3068\u306a\u308b\u64cd\u4f5c\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-2\">LEFT JOIN\u3068INNER JOIN\u306e\u57fa\u672c\u7684\u306a\u9055\u3044<\/h4>\n\n\n\n<p>LEFT JOIN\u3068INNER JOIN\u306e\u4e3b\u306a\u9055\u3044\u306f\u3001\u4ee5\u4e0b\u306e\u7279\u5fb4\u306b\u3042\u308a\u307e\u3059\uff1a<\/p>\n\n\n<div id=\"id-40ae8b3d-37f4-42a4-b738-2e30234ed708\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7279\u5fb4<\/th><th>LEFT JOIN<\/th><th>INNER JOIN<\/th><\/tr><\/thead><tbody><tr><td>\u7d50\u5408\u65b9\u5f0f<\/td><td>\u5de6\u30c6\u30fc\u30d6\u30eb\u306e\u5168\u30ec\u30b3\u30fc\u30c9\u3092\u4fdd\u6301<\/td><td>\u30de\u30c3\u30c1\u3059\u308b\u30ec\u30b3\u30fc\u30c9\u306e\u307f<\/td><\/tr><tr><td>NULL\u5024\u306e\u6271\u3044<\/td><td>\u53f3\u30c6\u30fc\u30d6\u30eb\u306b\u30de\u30c3\u30c1\u304c\u306a\u3044\u5834\u5408\u306fNULL<\/td><td>NULL\u306e\u30ec\u30b3\u30fc\u30c9\u306f\u9664\u5916<\/td><\/tr><tr><td>\u30c7\u30fc\u30bf\u306e\u5b8c\u5168\u6027<\/td><td>\u5de6\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u306f100%\u4fdd\u6301<\/td><td>\u4e21\u30c6\u30fc\u30d6\u30eb\u3067\u30de\u30c3\u30c1\u3059\u308b\u90e8\u5206\u306e\u307f<\/td><\/tr><tr><td>\u4f7f\u7528\u30b7\u30fc\u30f3<\/td><td>\u30c7\u30fc\u30bf\u306e\u6b20\u640d\u78ba\u8a8d\u3001\u5168\u4ef6\u306b\u5bfe\u3059\u308b\u95a2\u9023\u30c7\u30fc\u30bf\u306e\u53d6\u5f97<\/td><td>\u78ba\u5b9f\u306b\u95a2\u9023\u4ed8\u3051\u3089\u308c\u305f\u30c7\u30fc\u30bf\u306e\u307f\u5fc5\u8981\u306a\u5834\u5408<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u7c21\u5358\u306a\u4f8b\u3067\u8003\u3048\u3066\u307f\u307e\u3057\u3087\u3046\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">-- \u30c6\u30fc\u30d6\u30eb\u69cb\u9020\nusers            posts\n- id            - id\n- name          - user_id\n                - title\n\n-- \u30b5\u30f3\u30d7\u30eb\u30c7\u30fc\u30bf\n-- users\n1, '\u7530\u4e2d'\n2, '\u9234\u6728'\n3, '\u4f50\u85e4'\n\n-- posts\n1, 1, '\u521d\u6295\u7a3f'\n2, 1, '2\u756a\u76ee\u306e\u6295\u7a3f'\n3, 2, '\u9234\u6728\u3055\u3093\u306e\u6295\u7a3f'<\/pre>\n\n\n\n<p>\u3053\u306e\u3068\u304d\u3001LEFT JOIN\u3092\u4f7f\u7528\u3059\u308b\u3068\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">SELECT users.name, posts.title\nFROM users\nLEFT JOIN posts ON users.id = posts.user_id;\n\n-- \u7d50\u679c\n\u7530\u4e2d, '\u521d\u6295\u7a3f'\n\u7530\u4e2d, '2\u756a\u76ee\u306e\u6295\u7a3f'\n\u9234\u6728, '\u9234\u6728\u3055\u3093\u306e\u6295\u7a3f'\n\u4f50\u85e4, NULL<\/pre>\n\n\n\n<p>\u4e00\u65b9\u3001INNER JOIN\u306e\u5834\u5408\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">SELECT users.name, posts.title\nFROM users\nINNER JOIN posts ON users.id = posts.user_id;\n\n-- \u7d50\u679c\n\u7530\u4e2d, '\u521d\u6295\u7a3f'\n\u7530\u4e2d, '2\u756a\u76ee\u306e\u6295\u7a3f'\n\u9234\u6728, '\u9234\u6728\u3055\u3093\u306e\u6295\u7a3f'<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-3\">\u306a\u305cLaravel\u3067LEFT JOIN\u304c\u91cd\u8981\u306a\u306e\u304b<\/h3>\n\n\n\n<p>Laravel\u3067LEFT JOIN\u304c\u91cd\u8981\u8996\u3055\u308c\u308b\u7406\u7531\u306f\u4ee5\u4e0b\u306e\u70b9\u306b\u3042\u308a\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30c7\u30fc\u30bf\u306e\u5b8c\u5168\u6027\u306e\u78ba\u4fdd<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e6\u30fc\u30b6\u30fc\u60c5\u5831\u306e\u53d6\u5f97\u6642\u306b\u3001\u95a2\u9023\u30c7\u30fc\u30bf\u306e\u6709\u7121\u306b\u95a2\u308f\u3089\u305a\u5168\u30e6\u30fc\u30b6\u30fc\u306e\u60c5\u5831\u3092\u53d6\u5f97\u3067\u304d\u308b<\/li>\n\n\n\n<li>\u96c6\u8a08\u3084\u30ec\u30dd\u30fc\u30c8\u4f5c\u6210\u6642\u306b\u3001\u30c7\u30fc\u30bf\u304c\u5b58\u5728\u3057\u306a\u3044\u9805\u76ee\u3082\u542b\u3081\u3066\u6b63\u78ba\u306a\u60c5\u5831\u3092\u5f97\u3089\u308c\u308b<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Eloquent\u30e2\u30c7\u30eb\u3068\u306e\u89aa\u548c\u6027<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>HasOne\u3084HasMany\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u306b\u304a\u3044\u3066\u3001\u95a2\u9023\u30c7\u30fc\u30bf\u306e\u5b58\u5728\u78ba\u8a8d\u304c\u5bb9\u6613<\/li>\n\n\n\n<li>whereHas\u6761\u4ef6\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u67d4\u8edf\u306a\u30af\u30a8\u30ea\u69cb\u7bc9\u304c\u53ef\u80fd<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5fc5\u8981\u306a\u30c7\u30fc\u30bf\u306e\u307f\u3092\u52b9\u7387\u7684\u306b\u53d6\u5f97\u53ef\u80fd<\/li>\n\n\n\n<li>N+1\u554f\u984c\u306e\u89e3\u6c7a\u306b\u3082\u6d3b\u7528\u3067\u304d\u308b<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30d3\u30b8\u30cd\u30b9\u30ed\u30b8\u30c3\u30af\u306e\u5b9f\u88c5<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e6\u30fc\u30b6\u30fc\u306e\u6d3b\u52d5\u72b6\u6cc1\u306e\u8ffd\u8de1<\/li>\n\n\n\n<li>\u5728\u5eab\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u3067\u306e\u6b20\u54c1\u5546\u54c1\u306e\u628a\u63e1<\/li>\n\n\n\n<li>\u672a\u8aad\u30e1\u30c3\u30bb\u30fc\u30b8\u306e\u691c\u51fa\u306a\u3069<\/li>\n<\/ul>\n\n\n\n<p>\u305f\u3068\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30b1\u30fc\u30b9\u3067LEFT JOIN\u304c\u6709\u52b9\u3067\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u6295\u7a3f\u306e\u6709\u7121\u306b\u95a2\u308f\u3089\u305a\u5168\u30e6\u30fc\u30b6\u30fc\u3092\u53d6\u5f97\n$users = DB::table('users')\n    -&gt;leftJoin('posts', 'users.id', '=', 'posts.user_id')\n    -&gt;select('users.*', DB::raw('COUNT(posts.id) as post_count'))\n    -&gt;groupBy('users.id')\n    -&gt;get();<\/pre>\n\n\n\n<p>\u3053\u306e\u30af\u30a8\u30ea\u3067\u306f\u3001\u6295\u7a3f\u304c\u306a\u3044\u30e6\u30fc\u30b6\u30fc\u3082\u542b\u3081\u3066\u3001\u5168\u30e6\u30fc\u30b6\u30fc\u306e\u6295\u7a3f\u6570\u3092\u53d6\u5f97\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-4\">Laravel\u3067\u306eLEFT JOIN\u5b9f\u88c5\u65b9\u6cd5<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-5\">\u57fa\u672c\u7684\u306a\u69cb\u6587\u3068\u30af\u30a8\u30ea\u30d3\u30eb\u30c0\u30fc\u306e\u4f7f\u3044\u65b9<\/h3>\n\n\n\n<p>Laravel\u3067LEFT JOIN\u3092\u5b9f\u88c5\u3059\u308b\u65b9\u6cd5\u306f\u4e3b\u306b2\u3064\u3042\u308a\u307e\u3059\uff1a\u30af\u30a8\u30ea\u30d3\u30eb\u30c0\u30fc\u3092\u4f7f\u7528\u3059\u308b\u65b9\u6cd5\u3068Eloquent\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3092\u4f7f\u7528\u3059\u308b\u65b9\u6cd5\u3067\u3059\u3002\u307e\u305a\u306f\u57fa\u672c\u7684\u306a\u30af\u30a8\u30ea\u30d3\u30eb\u30c0\u30fc\u306e\u4f7f\u7528\u65b9\u6cd5\u3092\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-6\">\u30af\u30a8\u30ea\u30d3\u30eb\u30c0\u30fc\u3067\u306eLEFT JOIN<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u57fa\u672c\u7684\u306aLEFT JOIN\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;select('users.*', 'profiles.bio')\n    -&gt;get();\n\n\/\/ WHERE\u53e5\u3092\u7d44\u307f\u5408\u308f\u305b\u305f\u4f8b\n$activeUsers = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;where('users.status', 'active')\n    -&gt;select('users.*', 'profiles.bio')\n    -&gt;get();\n\n\/\/ \u30ab\u30e9\u30e0\u540d\u306e\u885d\u7a81\u3092\u907f\u3051\u308b\u305f\u3081\u306e\u5225\u540d\u4f7f\u7528\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;select(\n        'users.*',\n        'profiles.bio as profile_bio',\n        'profiles.avatar as profile_avatar'\n    )\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-7\">Eloquent\u30e2\u30c7\u30eb\u3067\u306e\u5b9f\u88c5<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ User\u30e2\u30c7\u30eb\u306e\u5b9a\u7fa9\nclass User extends Model\n{\n    public function profile()\n    {\n        return $this-&gt;hasOne(Profile::class);\n    }\n}\n\n\/\/ LEFT JOIN\u3092\u4f7f\u7528\u3057\u305f\u30af\u30a8\u30ea\n$users = User::query()\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;select('users.*', 'profiles.bio')\n    -&gt;get();<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-8\">\u8907\u6570\u30c6\u30fc\u30d6\u30eb\u3092\u7d50\u5408\u3059\u308b\u9ad8\u5ea6\u306a\u624b\u6cd5<\/h3>\n\n\n\n<p>\u8907\u6570\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u7d50\u5408\u3059\u308b\u5834\u5408\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059\uff1a<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-9\">\u9023\u7d9a\u3057\u305fLEFT JOIN<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ 3\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u7d50\u5408\u3059\u308b\u4f8b\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;leftJoin('posts', 'users.id', '=', 'posts.user_id')\n    -&gt;select(\n        'users.*',\n        'profiles.bio',\n        DB::raw('COUNT(DISTINCT posts.id) as post_count')\n    )\n    -&gt;groupBy('users.id', 'profiles.bio')\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-10\">\u6761\u4ef6\u4ed8\u304dLEFT JOIN<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u7279\u5b9a\u306e\u6761\u4ef6\u3092\u6301\u3064LEFT JOIN\n$users = DB::table('users')\n    -&gt;leftJoin('orders', function($join) {\n        $join-&gt;on('users.id', '=', 'orders.user_id')\n             -&gt;where('orders.status', '=', 'completed');\n    })\n    -&gt;select('users.*', DB::raw('COUNT(orders.id) as completed_orders'))\n    -&gt;groupBy('users.id')\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-11\">\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u7528\u3057\u305fLEFT JOIN<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30b5\u30d6\u30af\u30a8\u30ea\u3092\u542b\u3080LEFT JOIN\n$users = DB::table('users')\n    -&gt;leftJoin(DB::raw('(\n        SELECT user_id, COUNT(*) as order_count\n        FROM orders\n        GROUP BY user_id\n    ) as order_counts'), 'users.id', '=', 'order_counts.user_id')\n    -&gt;select('users.*', 'order_counts.order_count')\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-12\">\u5b9f\u88c5\u6642\u306e\u91cd\u8981\u306a\u30dd\u30a4\u30f3\u30c8<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30ab\u30e9\u30e0\u540d\u306e\u660e\u793a\u7684\u306a\u6307\u5b9a<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30c6\u30fc\u30d6\u30eb\u540d\u3092\u660e\u793a\u7684\u306b\u6307\u5b9a\u3059\u308b\u3053\u3068\u3067\u3001\u30ab\u30e9\u30e0\u306e\u885d\u7a81\u3092\u9632\u304e\u307e\u3059<\/li>\n\n\n\n<li>\u5fc5\u8981\u306b\u5fdc\u3058\u3066\u30ab\u30e9\u30e0\u306b\u30a8\u30a4\u30ea\u30a2\u30b9\u3092\u8a2d\u5b9a\u3057\u307e\u3059<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>NULL\u5024\u306e\u8003\u616e<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>LEFT JOIN\u306e\u7d50\u679c\u306b\u306fNULL\u5024\u304c\u542b\u307e\u308c\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u305f\u3081\u3001\u9069\u5207\u306b\u51e6\u7406\u3057\u307e\u3059<\/li>\n\n\n\n<li><code>COALESCE<\/code>\u3084<code>IFNULL<\/code>\u95a2\u6570\u3092\u4f7f\u7528\u3057\u3066\u3001NULL\u5024\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u5024\u3092\u8a2d\u5b9a\u3067\u304d\u307e\u3059<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3078\u306e\u914d\u616e<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5fc5\u8981\u306a\u30ab\u30e9\u30e0\u306e\u307f\u3092<code>select<\/code>\u3059\u308b\u3053\u3068\u3067\u3001\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u3092\u6291\u3048\u307e\u3059<\/li>\n\n\n\n<li>\u9069\u5207\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u3067\u3001\u7d50\u5408\u51e6\u7406\u3092\u6700\u9069\u5316\u3057\u307e\u3059<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30af\u30a8\u30ea\u306e\u53ef\u8aad\u6027<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8907\u96d1\u306aJOIN\u306f\u9069\u5207\u306b\u6539\u884c\u3068\u30a4\u30f3\u30c7\u30f3\u30c8\u3092\u5165\u308c\u3066\u8a18\u8ff0\u3057\u307e\u3059<\/li>\n\n\n\n<li>\u5fc5\u8981\u306b\u5fdc\u3058\u3066\u30af\u30a8\u30ea\u3092\u30e1\u30bd\u30c3\u30c9\u306b\u5206\u5272\u3057\u3001\u518d\u5229\u7528\u53ef\u80fd\u306b\u3057\u307e\u3059<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-13\">\u5b9f\u8df5\u7684\u306aLEFT JOIN\u306e\u6d3b\u7528\u30b7\u30fc\u30f3<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-14\">\u5b58\u5728\u3057\u306a\u3044\u30c7\u30fc\u30bf\u3082\u542b\u3081\u305f\u96c6\u8a08\u30ec\u30dd\u30fc\u30c8\u306e\u4f5c\u6210\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u96c6\u8a08\u30ec\u30dd\u30fc\u30c8\u306e\u4f5c\u6210\u306f\u3001LEFT JOIN\u306e\u6700\u3082\u91cd\u8981\u306a\u6d3b\u7528\u30b7\u30fc\u30f3\u306e1\u3064\u3067\u3059\u3002\u7279\u306b\u3001\u30c7\u30fc\u30bf\u304c\u5b58\u5728\u3057\u306a\u3044\u5834\u5408\u3082\u542b\u3081\u3066\u6b63\u78ba\u306a\u7d71\u8a08\u3092\u53d6\u308b\u5fc5\u8981\u304c\u3042\u308b\u5834\u5408\u306b\u5a01\u529b\u3092\u767a\u63ee\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-15\">\u6708\u5225\u58f2\u4e0a\u30ec\u30dd\u30fc\u30c8\u306e\u4f8b<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u58f2\u4e0a\u304c\u7121\u3044\u6708\u3082\u542b\u3081\u305f\u6708\u6b21\u30ec\u30dd\u30fc\u30c8\u306e\u4f5c\u6210\n$monthlyReport = DB::table('months') \/\/ \u6708\u306e\u30de\u30b9\u30bf\u30fc\u30c6\u30fc\u30d6\u30eb\n    -&gt;leftJoin('orders', function($join) {\n        $join-&gt;on(DB::raw('MONTH(orders.created_at)'), '=', 'months.month_number')\n            -&gt;whereYear('orders.created_at', '=', '2024');\n    })\n    -&gt;select(\n        'months.month_number',\n        'months.month_name',\n        DB::raw('COALESCE(SUM(orders.amount), 0) as total_amount'),\n        DB::raw('COUNT(DISTINCT orders.id) as order_count')\n    )\n    -&gt;groupBy('months.month_number', 'months.month_name')\n    -&gt;orderBy('months.month_number')\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-16\">\u30ab\u30c6\u30b4\u30ea\u30fc\u5225\u5546\u54c1\u30ab\u30a6\u30f3\u30c8\u306e\u4f8b<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5546\u54c1\u304c\u767b\u9332\u3055\u308c\u3066\u3044\u306a\u3044\u30ab\u30c6\u30b4\u30ea\u30fc\u3082\u542b\u3081\u305f\u96c6\u8a08\n$categoryStats = DB::table('categories')\n    -&gt;leftJoin('products', 'categories.id', '=', 'products.category_id')\n    -&gt;select(\n        'categories.name',\n        DB::raw('COUNT(products.id) as product_count'),\n        DB::raw('COALESCE(AVG(products.price), 0) as avg_price')\n    )\n    -&gt;groupBy('categories.id', 'categories.name')\n    -&gt;get();<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-17\">\u95a2\u9023\u30c7\u30fc\u30bf\u306e\u6709\u7121\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u52b9\u7387\u7684\u306a\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u95a2\u9023\u30c7\u30fc\u30bf\u306e\u5b58\u5728\u78ba\u8a8d\u306f\u3001\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u306e\u69d8\u3005\u306a\u5834\u9762\u3067\u5fc5\u8981\u3068\u306a\u308a\u307e\u3059\u3002LEFT JOIN\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u52b9\u7387\u7684\u306b\u3053\u308c\u3089\u306e\u30c1\u30a7\u30c3\u30af\u3092\u884c\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-18\">\u30e6\u30fc\u30b6\u30fc\u306e\u6d3b\u52d5\u72b6\u6cc1\u30c1\u30a7\u30c3\u30af<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u904e\u53bb30\u65e5\u9593\u306e\u6d3b\u52d5\u304c\u306a\u3044\u30e6\u30fc\u30b6\u30fc\u3092\u691c\u51fa\n$inactiveUsers = DB::table('users')\n    -&gt;leftJoin('activities', function($join) {\n        $join-&gt;on('users.id', '=', 'activities.user_id')\n            -&gt;where('activities.created_at', '&gt;=', now()-&gt;subDays(30));\n    })\n    -&gt;whereNull('activities.id')\n    -&gt;select('users.*')\n    -&gt;get();\n\n\/\/ Eloquent\u3092\u4f7f\u7528\u3057\u305f\u5834\u5408\n$inactiveUsers = User::query()\n    -&gt;leftJoin('activities', function($join) {\n        $join-&gt;on('users.id', '=', 'activities.user_id')\n            -&gt;where('activities.created_at', '&gt;=', now()-&gt;subDays(30));\n    })\n    -&gt;whereNull('activities.id')\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-19\">\u672a\u5b8c\u4e86\u30bf\u30b9\u30af\u306e\u691c\u51fa<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u5225\u306e\u672a\u5b8c\u4e86\u30bf\u30b9\u30af\u691c\u51fa\n$projectStatus = DB::table('projects')\n    -&gt;leftJoin('tasks', function($join) {\n        $join-&gt;on('projects.id', '=', 'tasks.project_id')\n            -&gt;where('tasks.status', '!=', 'completed')\n            -&gt;orWhereNull('tasks.status');\n    })\n    -&gt;select(\n        'projects.name',\n        DB::raw('COUNT(DISTINCT tasks.id) as incomplete_tasks'),\n        DB::raw('MAX(tasks.due_date) as next_due_date')\n    )\n    -&gt;groupBy('projects.id', 'projects.name')\n    -&gt;having('incomplete_tasks', '&gt;', 0)\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-20\">\u5b9f\u88c5\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u96c6\u8a08\u6642\u306eNULL\u5024\u306e\u51e6\u7406<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   \/\/ BAD\n   DB::raw('SUM(amount) as total_amount')\n\n   \/\/ GOOD\n   DB::raw('COALESCE(SUM(amount), 0) as total_amount')<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u6761\u4ef6\u4ed8\u304dJOIN\u306e\u6d3b\u7528<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   \/\/ \u7279\u5b9a\u671f\u9593\u306e\u30c7\u30fc\u30bf\u306e\u307f\u3092\u7d50\u5408\n   -&gt;leftJoin('orders', function($join) {\n       $join-&gt;on('users.id', '=', 'orders.user_id')\n           -&gt;whereBetween('orders.created_at', [\n               now()-&gt;startOfMonth(),\n               now()-&gt;endOfMonth()\n           ]);\n   })<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u8907\u6570\u306e\u96c6\u8a08\u30921\u3064\u306e\u30af\u30a8\u30ea\u3067\u5b9f\u884c<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   $userStats = DB::table('users')\n       -&gt;leftJoin('orders', 'users.id', '=', 'orders.user_id')\n       -&gt;leftJoin('reviews', 'users.id', '=', 'reviews.user_id')\n       -&gt;select(\n           'users.id',\n           'users.name',\n           DB::raw('COUNT(DISTINCT orders.id) as order_count'),\n           DB::raw('COUNT(DISTINCT reviews.id) as review_count'),\n           DB::raw('COALESCE(AVG(reviews.rating), 0) as avg_rating')\n       )\n       -&gt;groupBy('users.id', 'users.name')\n       -&gt;get();<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5b9f\u88c5\u4f8b\u306f\u3001\u5b9f\u969b\u306e\u30d3\u30b8\u30cd\u30b9\u30ed\u30b8\u30c3\u30af\u306b\u5fdc\u3058\u3066\u9069\u5207\u306b\u30ab\u30b9\u30bf\u30de\u30a4\u30ba\u3057\u3066\u304f\u3060\u3055\u3044\u3002\u307e\u305f\u3001\u5927\u898f\u6a21\u306a\u30c7\u30fc\u30bf\u3092\u6271\u3046\u5834\u5408\u306f\u3001\u30af\u30a8\u30ea\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u6ce8\u610f\u3092\u6255\u3044\u3001\u5fc5\u8981\u306b\u5fdc\u3058\u3066\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8a2d\u5b9a\u3084\u30af\u30a8\u30ea\u306e\u6700\u9069\u5316\u3092\u691c\u8a0e\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-21\">LEFT JOIN\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6700\u9069\u5316<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-22\">\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u9069\u5207\u306a\u8a2d\u5b9a\u65b9\u6cd5<\/h3>\n\n\n\n<p>LEFT JOIN\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u6700\u9069\u5316\u3059\u308b\u4e0a\u3067\u3001\u9069\u5207\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u8a2d\u5b9a\u306f\u6700\u3082\u91cd\u8981\u306a\u8981\u7d20\u306e\u4e00\u3064\u3067\u3059\u3002\u4ee5\u4e0b\u3001\u52b9\u679c\u7684\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u8a2d\u5b9a\u306e\u65b9\u6cd5\u3092\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-23\">\u7d50\u5408\u30ad\u30fc\u3078\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u8a2d\u5b9a<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30de\u30a4\u30b0\u30ec\u30fc\u30b7\u30e7\u30f3\u3067\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u8a2d\u5b9a\u4f8b\nSchema::create('orders', function (Blueprint $table) {\n    $table-&gt;id();\n    $table-&gt;foreignId('user_id')-&gt;constrained(); \/\/ \u5916\u90e8\u30ad\u30fc\u5236\u7d04\u306b\u3088\u308a\u81ea\u52d5\u7684\u306b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u304c\u4f5c\u6210\u3055\u308c\u308b\n    $table-&gt;string('status');\n    $table-&gt;timestamps();\n\n    \/\/ \u8907\u5408\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u4f8b\n    $table-&gt;index(['user_id', 'status']); \/\/ \u983b\u7e41\u306b\u4f7f\u7528\u3055\u308c\u308b\u691c\u7d22\u6761\u4ef6\u306e\u7d44\u307f\u5408\u308f\u305b\n});\n\n\/\/ \u65e2\u5b58\u30c6\u30fc\u30d6\u30eb\u3078\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u8ffd\u52a0\nSchema::table('orders', function (Blueprint $table) {\n    $table-&gt;index('user_id');\n    $table-&gt;index(['created_at', 'status']); \/\/ \u65e5\u4ed8\u7bc4\u56f2\u691c\u7d22\u3068\u30b9\u30c6\u30fc\u30bf\u30b9\u3067\u306e\u7d5e\u308a\u8fbc\u307f\u306b\u6709\u52b9\n});<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-24\">\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u8a2d\u8a08\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u7d50\u5408\u6761\u4ef6\u306e\u30ab\u30e9\u30e0<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5916\u90e8\u30ad\u30fc\u306b\u306f\u5fc5\u305a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u8a2d\u5b9a<\/li>\n\n\n\n<li>\u7d50\u5408\u306b\u4f7f\u7528\u3055\u308c\u308b\u30ab\u30e9\u30e0\u306e\u7d44\u307f\u5408\u308f\u305b\u306b\u6ce8\u76ee<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>WHERE\u53e5\u3067\u4f7f\u7528\u3055\u308c\u308b\u30ab\u30e9\u30e0<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u691c\u7d22\u6761\u4ef6\u3068\u3057\u3066\u983b\u7e41\u306b\u4f7f\u7528\u3055\u308c\u308b\u30ab\u30e9\u30e0\u306b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u8a2d\u5b9a<\/li>\n\n\n\n<li>\u8907\u6570\u306e\u30ab\u30e9\u30e0\u3092\u7d44\u307f\u5408\u308f\u305b\u305f\u691c\u7d22\u306b\u306f\u8907\u5408\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u691c\u8a0e<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30ab\u30fc\u30c7\u30a3\u30ca\u30ea\u30c6\u30a3\u306e\u8003\u616e<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e6\u30cb\u30fc\u30af\u6027\u306e\u9ad8\u3044\u30ab\u30e9\u30e0\u307b\u3069\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u52b9\u679c\u304c\u9ad8\u3044<\/li>\n\n\n\n<li>\u30b9\u30c6\u30fc\u30bf\u30b9\u306a\u3069\u7a2e\u985e\u306e\u5c11\u306a\u3044\u30ab\u30e9\u30e0\u306f\u5358\u72ec\u3067\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306f\u907f\u3051\u308b<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-25\">N+1\u554f\u984c\u3092\u56de\u907f\u3059\u308b\u305f\u3081\u306e\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>N+1\u554f\u984c\u306fLEFT JOIN\u3092\u4f7f\u7528\u3059\u308b\u969b\u306b\u3088\u304f\u767a\u751f\u3059\u308b\u6027\u80fd\u554f\u984c\u3067\u3059\u3002\u4ee5\u4e0b\u306b\u3001\u52b9\u679c\u7684\u306a\u56de\u907f\u65b9\u6cd5\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-26\">Eager\u30ed\u30fc\u30c7\u30a3\u30f3\u30b0\u306e\u6d3b\u7528<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ N+1\u554f\u984c\u304c\u767a\u751f\u3059\u308b\u30b3\u30fc\u30c9\n$users = User::all(); \/\/ 1\u56de\u306e\u30af\u30a8\u30ea\nforeach ($users as $user) {\n    $user-&gt;profile; \/\/ \u5404\u30e6\u30fc\u30b6\u30fc\u3054\u3068\u306b\u8ffd\u52a0\u30af\u30a8\u30ea\u304c\u767a\u751f\n}\n\n\/\/ Eager\u30ed\u30fc\u30c7\u30a3\u30f3\u30b0\u3092\u4f7f\u7528\u3057\u305f\u6539\u5584\u4f8b\n$users = User::with('profile')-&gt;get(); \/\/ 2\u56de\u306e\u30af\u30a8\u30ea\u306e\u307f\n\n\/\/ \u6761\u4ef6\u4ed8\u304dEager\u30ed\u30fc\u30c7\u30a3\u30f3\u30b0\n$users = User::with(['profile' =&gt; function ($query) {\n    $query-&gt;select('user_id', 'bio', 'avatar'); \/\/ \u5fc5\u8981\u306a\u30ab\u30e9\u30e0\u306e\u307f\u53d6\u5f97\n}])-&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-27\">JOIN\u6587\u306e\u9069\u5207\u306a\u4f7f\u7528<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5fc5\u8981\u306a\u30c7\u30fc\u30bf\u306e\u307f\u30921\u56de\u306e\u30af\u30a8\u30ea\u3067\u53d6\u5f97\n$users = User::select('users.*', 'profiles.bio')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;where('users.status', 'active')\n    -&gt;get();\n\n\/\/ \u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u7528\u3057\u305f\u6700\u9069\u5316\u4f8b\n$users = User::select('users.*')\n    -&gt;addSelect([\n        'latest_order_date' =&gt; Order::select('created_at')\n            -&gt;whereColumn('user_id', 'users.id')\n            -&gt;latest()\n            -&gt;limit(1)\n    ])\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-28\">\u30af\u30a8\u30ea\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5fc5\u8981\u306a\u30ab\u30e9\u30e0\u306e\u307f\u306e\u53d6\u5f97<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ BAD\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;get(); \/\/ \u5168\u30ab\u30e9\u30e0\u3092\u53d6\u5f97\n\n\/\/ GOOD\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;select('users.id', 'users.name', 'profiles.bio')\n    -&gt;get(); \/\/ \u5fc5\u8981\u306a\u30ab\u30e9\u30e0\u306e\u307f\u53d6\u5f97<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30af\u30a8\u30ea\u306e\u30c1\u30e3\u30f3\u30af\u51e6\u7406<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5927\u91cf\u30c7\u30fc\u30bf\u306e\u51e6\u7406\nUser::with('profile')\n    -&gt;chunk(1000, function ($users) {\n        foreach ($users as $user) {\n            \/\/ \u30e6\u30fc\u30b6\u30fc\u51e6\u7406\n        }\n    });<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u30ad\u30e3\u30c3\u30b7\u30e5\u306e\u6d3b\u7528<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30ad\u30e3\u30c3\u30b7\u30e5\u3092\u4f7f\u7528\u3057\u305f\u6700\u9069\u5316\n$users = Cache::remember('active_users', now()-&gt;addHours(1), function () {\n    return User::select('users.*', 'profiles.bio')\n        -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n        -&gt;where('users.status', 'active')\n        -&gt;get();\n});<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-29\">\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30e2\u30cb\u30bf\u30ea\u30f3\u30b0<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30af\u30a8\u30ea\u30ed\u30b0\u306e\u6d3b\u7528<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u958b\u767a\u74b0\u5883\u3067\u306e\u30af\u30a8\u30ea\u30ed\u30b0\u6709\u52b9\u5316\nDB::connection()-&gt;enableQueryLog();\n\/\/ \u30af\u30a8\u30ea\u5b9f\u884c\n$users = User::with('profile')-&gt;get();\n\/\/ \u30ed\u30b0\u306e\u78ba\u8a8d\ndd(DB::getQueryLog());<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u5b9f\u884c\u8a08\u753b\u306e\u78ba\u8a8d<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30af\u30a8\u30ea\u306e\u5b9f\u884c\u8a08\u753b\u3092\u78ba\u8a8d\n$explain = DB::select('EXPLAIN SELECT users.*, profiles.bio \n    FROM users \n    LEFT JOIN profiles ON users.id = profiles.user_id \n    WHERE users.status = \"active\"');<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af\u3092\u9069\u5207\u306b\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001LEFT JOIN\u3092\u4f7f\u7528\u3057\u305f\u8907\u96d1\u306a\u30af\u30a8\u30ea\u3067\u3082\u9ad8\u3044\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u7dad\u6301\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u305f\u3060\u3057\u3001\u904e\u5ea6\u306a\u6700\u9069\u5316\u306f\u53ef\u8aad\u6027\u3084\u4fdd\u5b88\u6027\u3092\u640d\u306a\u3046\u53ef\u80fd\u6027\u304c\u3042\u308b\u305f\u3081\u3001\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u306e\u8981\u4ef6\u306b\u5fdc\u3058\u3066\u9069\u5207\u306a\u30d0\u30e9\u30f3\u30b9\u3092\u53d6\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-30\">LEFT JOIN\u3067\u3088\u304f\u3042\u308b\u30a8\u30e9\u30fc\u3068\u305d\u306e\u89e3\u6c7a\u6cd5<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-31\">\u30ab\u30e9\u30e0\u540d\u306e\u885d\u7a81\u3092\u9632\u3050\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h3>\n\n\n\n<p>\u30ab\u30e9\u30e0\u540d\u306e\u885d\u7a81\u306f\u3001LEFT JOIN\u3092\u4f7f\u7528\u3059\u308b\u969b\u306b\u3088\u304f\u906d\u9047\u3059\u308b\u554f\u984c\u306e\u4e00\u3064\u3067\u3059\u3002\u4ee5\u4e0b\u306b\u4e3b\u306a\u554f\u984c\u30d1\u30bf\u30fc\u30f3\u3068\u89e3\u6c7a\u65b9\u6cd5\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-32\">\u554f\u984c\u30d1\u30bf\u30fc\u30f31: \u3042\u3044\u307e\u3044\u306a\u30ab\u30e9\u30e0\u53c2\u7167<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30a8\u30e9\u30fc\u304c\u767a\u751f\u3059\u308b\u30af\u30a8\u30ea\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;select('id', 'name', 'email') \/\/ ambiguous column 'id'\u30a8\u30e9\u30fc\u304c\u767a\u751f\n    -&gt;get();\n\n\/\/ \u6b63\u3057\u3044\u5b9f\u88c5\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;select('users.id', 'users.name', 'users.email') \/\/ \u30c6\u30fc\u30d6\u30eb\u540d\u3092\u660e\u793a\u7684\u306b\u6307\u5b9a\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-33\">\u554f\u984c\u30d1\u30bf\u30fc\u30f32: \u540c\u540d\u30ab\u30e9\u30e0\u306e\u885d\u7a81<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u554f\u984c\u306e\u3042\u308b\u30af\u30a8\u30ea\n$posts = DB::table('posts')\n    -&gt;leftJoin('post_translations', 'posts.id', '=', 'post_translations.post_id')\n    -&gt;select('posts.*', 'post_translations.*') \/\/ title\u306a\u3069\u540c\u540d\u30ab\u30e9\u30e0\u304c\u885d\u7a81\n    -&gt;get();\n\n\/\/ \u89e3\u6c7a\u65b9\u6cd51: \u30a8\u30a4\u30ea\u30a2\u30b9\u306e\u4f7f\u7528\n$posts = DB::table('posts')\n    -&gt;leftJoin('post_translations', 'posts.id', '=', 'post_translations.post_id')\n    -&gt;select(\n        'posts.*',\n        'post_translations.title as translated_title',\n        'post_translations.content as translated_content'\n    )\n    -&gt;get();\n\n\/\/ \u89e3\u6c7a\u65b9\u6cd52: \u5fc5\u8981\u306a\u30ab\u30e9\u30e0\u306e\u307f\u3092\u660e\u793a\u7684\u306b\u9078\u629e\n$posts = DB::table('posts')\n    -&gt;leftJoin('post_translations', 'posts.id', '=', 'post_translations.post_id')\n    -&gt;select(\n        'posts.id',\n        'posts.title as original_title',\n        'post_translations.title as translated_title'\n    )\n    -&gt;get();<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-34\">NULL\u5024\u306e\u9069\u5207\u306a\u51e6\u7406\u65b9\u6cd5<\/h3>\n\n\n\n<p>NULL\u5024\u306e\u51e6\u7406\u306f\u3001LEFT JOIN\u3092\u4f7f\u7528\u3059\u308b\u969b\u306e\u91cd\u8981\u306a\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u3002\u4ee5\u4e0b\u306b\u4e3b\u306a\u554f\u984c\u30d1\u30bf\u30fc\u30f3\u3068\u89e3\u6c7a\u65b9\u6cd5\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-35\">NULL\u5024\u306e\u6761\u4ef6\u30c1\u30a7\u30c3\u30af<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u8aa4\u3063\u305f\u5b9f\u88c5\uff08NULL\u5024\u3092\u898b\u9003\u3059\u53ef\u80fd\u6027\u304c\u3042\u308b\uff09\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;where('profiles.status', 'active') \/\/ NULL\u5024\u306e\u30ec\u30b3\u30fc\u30c9\u304c\u9664\u5916\u3055\u308c\u308b\n    -&gt;get();\n\n\/\/ \u6b63\u3057\u3044\u5b9f\u88c5\n$users = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;where(function($query) {\n        $query-&gt;where('profiles.status', 'active')\n              -&gt;orWhereNull('profiles.status');\n    })\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-36\">NULL\u5024\u306e\u96c6\u8a08\u51e6\u7406<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u554f\u984c\u306e\u3042\u308b\u96c6\u8a08\u30af\u30a8\u30ea\n$result = DB::table('orders')\n    -&gt;leftJoin('order_details', 'orders.id', '=', 'order_details.order_id')\n    -&gt;select(\n        'orders.id',\n        DB::raw('SUM(order_details.amount) as total_amount') \/\/ NULL\u5024\u304c\u6b63\u3057\u304f\u51e6\u7406\u3055\u308c\u306a\u3044\n    )\n    -&gt;groupBy('orders.id')\n    -&gt;get();\n\n\/\/ \u6b63\u3057\u3044\u5b9f\u88c5\uff1aCOALESCE\u3092\u4f7f\u7528\n$result = DB::table('orders')\n    -&gt;leftJoin('order_details', 'orders.id', '=', 'order_details.order_id')\n    -&gt;select(\n        'orders.id',\n        DB::raw('COALESCE(SUM(order_details.amount), 0) as total_amount')\n    )\n    -&gt;groupBy('orders.id')\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-37\">\u3088\u304f\u3042\u308b\u30a8\u30e9\u30fc\u3068\u305d\u306e\u5bfe\u51e6\u6cd5<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>WHERE\u53e5\u3067\u306eNULL\u5024\u306e\u6271\u3044<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30a8\u30e9\u30fc\u30d1\u30bf\u30fc\u30f3\n-&gt;where('related_table.column', '!=', 'some_value') \/\/ NULL\u5024\u304c\u8003\u616e\u3055\u308c\u306a\u3044\n\n\/\/ \u6b63\u3057\u3044\u5b9f\u88c5\n-&gt;where(function($query) {\n    $query-&gt;where('related_table.column', '!=', 'some_value')\n          -&gt;orWhereNull('related_table.column');\n})<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u96c6\u8a08\u95a2\u6570\u3067\u306eNULL\u5024\u306e\u51e6\u7406<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u96c6\u8a08\u6642\u306eNULL\u5024\u5bfe\u7b56\nDB::raw('COALESCE(AVG(ratings.score), 0) as average_rating'),\nDB::raw('COALESCE(COUNT(DISTINCT comments.id), 0) as comment_count')<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u6761\u4ef6\u4ed8\u304d\u30c7\u30fc\u30bf\u53d6\u5f97<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u8907\u96d1\u306a\u6761\u4ef6\u3067\u306eNULL\u5024\u51e6\u7406\n$users = DB::table('users')\n    -&gt;leftJoin('last_login_logs', function($join) {\n        $join-&gt;on('users.id', '=', 'last_login_logs.user_id')\n             -&gt;where(function($query) {\n                 $query-&gt;whereNull('last_login_logs.created_at')\n                       -&gt;orWhere('last_login_logs.created_at', '&lt;=', now()-&gt;subDays(30));\n             });\n    })\n    -&gt;select('users.*', 'last_login_logs.created_at as last_login')\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-38\">\u30c7\u30d0\u30c3\u30b0\u306e\u30d2\u30f3\u30c8<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30af\u30a8\u30ea\u30ed\u30b0\u306e\u78ba\u8a8d<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30af\u30a8\u30ea\u30ed\u30b0\u3092\u6709\u52b9\u5316\nDB::enableQueryLog();\n\n\/\/ \u30af\u30a8\u30ea\u5b9f\u884c\n$result = DB::table('users')\n    -&gt;leftJoin('profiles', 'users.id', '=', 'profiles.user_id')\n    -&gt;get();\n\n\/\/ \u751f\u6210\u3055\u308c\u305fSQL\u306e\u78ba\u8a8d\ndd(DB::getQueryLog());<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u5b9f\u884c\u8a08\u753b\u306e\u78ba\u8a8d<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5b9f\u884c\u8a08\u753b\u306e\u53d6\u5f97\n$explain = DB::select('EXPLAIN ' . $query-&gt;toSql());<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u30a8\u30e9\u30fc\u30d1\u30bf\u30fc\u30f3\u3068\u89e3\u6c7a\u65b9\u6cd5\u3092\u7406\u89e3\u3059\u308b\u3053\u3068\u3067\u3001LEFT JOIN\u3092\u4f7f\u7528\u3059\u308b\u969b\u306e\u4e00\u822c\u7684\u306a\u554f\u984c\u3092\u52b9\u679c\u7684\u306b\u56de\u907f\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u307e\u305f\u3001\u30c7\u30d0\u30c3\u30b0\u6642\u306b\u306f\u5fc5\u305a\u30af\u30a8\u30ea\u30ed\u30b0\u3084\u5b9f\u884c\u8a08\u753b\u3092\u78ba\u8a8d\u3057\u3001\u554f\u984c\u306e\u65e9\u671f\u767a\u898b\u3068\u89e3\u6c7a\u306b\u52aa\u3081\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-39\">LEFT JOIN\u3092\u4f7f\u7528\u3057\u305f\u5b9f\u88c5\u4f8b<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-40\">EC\u30b5\u30a4\u30c8\u306e\u5728\u5eab\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u3067\u306e\u6d3b\u7528\u4f8b<\/h3>\n\n\n\n<p>EC\u30b5\u30a4\u30c8\u306e\u5728\u5eab\u7ba1\u7406\u306f\u3001LEFT JOIN\u306e\u6d3b\u7528\u304c\u52b9\u679c\u7684\u306a\u4ee3\u8868\u7684\u306a\u30b1\u30fc\u30b9\u3067\u3059\u3002\u4ee5\u4e0b\u306b\u5177\u4f53\u7684\u306a\u5b9f\u88c5\u4f8b\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-41\">\u5728\u5eab\u72b6\u6cc1\u306e\u53d6\u5f97\u3068\u8868\u793a<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5546\u54c1\u30e2\u30c7\u30eb\nclass Product extends Model\n{\n    public function inventory()\n    {\n        return $this-&gt;hasOne(Inventory::class);\n    }\n\n    public function category()\n    {\n        return $this-&gt;belongsTo(Category::class);\n    }\n}\n\n\/\/ \u5728\u5eab\u7ba1\u7406\u7528\u306e\u30b3\u30f3\u30c8\u30ed\u30fc\u30e9\u30fc\nclass InventoryController extends Controller\n{\n    public function index()\n    {\n        \/\/ \u5728\u5eab\u72b6\u6cc1\u4e00\u89a7\u306e\u53d6\u5f97\n        $products = DB::table('products')\n            -&gt;leftJoin('inventory', 'products.id', '=', 'inventory.product_id')\n            -&gt;leftJoin('categories', 'products.category_id', '=', 'categories.id')\n            -&gt;select(\n                'products.id',\n                'products.name',\n                'products.price',\n                'categories.name as category_name',\n                'inventory.quantity',\n                DB::raw('CASE \n                    WHEN inventory.quantity IS NULL THEN \"\u5728\u5eab\u306a\u3057\"\n                    WHEN inventory.quantity = 0 THEN \"\u58f2\u308a\u5207\u308c\"\n                    WHEN inventory.quantity &lt; 10 THEN \"\u6b8b\u308a\u308f\u305a\u304b\"\n                    ELSE \"\u5728\u5eab\u3042\u308a\"\n                END as stock_status')\n            )\n            -&gt;get();\n\n        return view('inventory.index', compact('products'));\n    }\n\n    public function lowStockAlert()\n    {\n        \/\/ \u5728\u5eab\u6b8b\u308a\u50c5\u304b\u306a\u5546\u54c1\u306e\u30a2\u30e9\u30fc\u30c8\n        $lowStockProducts = DB::table('products')\n            -&gt;leftJoin('inventory', 'products.id', '=', 'inventory.product_id')\n            -&gt;where(function($query) {\n                $query-&gt;where('inventory.quantity', '&lt;', 10)\n                      -&gt;orWhereNull('inventory.quantity');\n            })\n            -&gt;select(\n                'products.id',\n                'products.name',\n                'inventory.quantity',\n                DB::raw('COALESCE(inventory.quantity, 0) as current_stock')\n            )\n            -&gt;orderBy('current_stock')\n            -&gt;get();\n\n        return $lowStockProducts;\n    }\n}<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-42\">\u5728\u5eab\u5c65\u6b74\u306e\u8ffd\u8de1<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5728\u5eab\u5c65\u6b74\u306e\u53d6\u5f97\u3068\u5206\u6790\nclass InventoryHistoryService\n{\n    public function getStockHistory($productId, $period = 30)\n    {\n        return DB::table('products')\n            -&gt;leftJoin('inventory_history', function($join) use ($period) {\n                $join-&gt;on('products.id', '=', 'inventory_history.product_id')\n                     -&gt;whereBetween('inventory_history.created_at', [\n                         now()-&gt;subDays($period),\n                         now()\n                     ]);\n            })\n            -&gt;where('products.id', $productId)\n            -&gt;select(\n                'products.name',\n                'inventory_history.quantity',\n                'inventory_history.type', \/\/ \u5165\u5eab\/\u51fa\u5eab\n                'inventory_history.created_at'\n            )\n            -&gt;orderBy('inventory_history.created_at', 'desc')\n            -&gt;get();\n    }\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-43\">\u30d6\u30ed\u30b0\u8a18\u4e8b\u3068\u30b3\u30e1\u30f3\u30c8\u306e\u95a2\u9023\u4ed8\u3051\u5b9f\u88c5<\/h3>\n\n\n\n<p>\u30d6\u30ed\u30b0\u30b7\u30b9\u30c6\u30e0\u3067\u306eLEFT JOIN\u306e\u6d3b\u7528\u4f8b\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-44\">\u8a18\u4e8b\u3068\u30b3\u30e1\u30f3\u30c8\u306e\u53d6\u5f97<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u8a18\u4e8b\u30e2\u30c7\u30eb\nclass Article extends Model\n{\n    public function comments()\n    {\n        return $this-&gt;hasMany(Comment::class);\n    }\n\n    public function author()\n    {\n        return $this-&gt;belongsTo(User::class, 'user_id');\n    }\n}\n\n\/\/ \u30d6\u30ed\u30b0\u30b3\u30f3\u30c8\u30ed\u30fc\u30e9\u30fc\nclass BlogController extends Controller\n{\n    public function index()\n    {\n        \/\/ \u8a18\u4e8b\u4e00\u89a7\u3068\u30b3\u30e1\u30f3\u30c8\u6570\u306e\u53d6\u5f97\n        $articles = DB::table('articles')\n            -&gt;leftJoin('comments', 'articles.id', '=', 'comments.article_id')\n            -&gt;leftJoin('users', 'articles.user_id', '=', 'users.id')\n            -&gt;select(\n                'articles.id',\n                'articles.title',\n                'articles.content',\n                'users.name as author_name',\n                DB::raw('COUNT(DISTINCT comments.id) as comment_count'),\n                DB::raw('MAX(comments.created_at) as latest_comment_date')\n            )\n            -&gt;groupBy(\n                'articles.id',\n                'articles.title',\n                'articles.content',\n                'users.name'\n            )\n            -&gt;orderBy('articles.created_at', 'desc')\n            -&gt;get();\n\n        return view('blog.index', compact('articles'));\n    }\n\n    public function show($id)\n    {\n        \/\/ \u8a18\u4e8b\u8a73\u7d30\u3068\u30b3\u30e1\u30f3\u30c8\u306e\u53d6\u5f97\n        $article = DB::table('articles')\n            -&gt;leftJoin('comments', function($join) {\n                $join-&gt;on('articles.id', '=', 'comments.article_id')\n                     -&gt;whereNull('comments.deleted_at'); \/\/ \u524a\u9664\u3055\u308c\u3066\u3044\u306a\u3044\u30b3\u30e1\u30f3\u30c8\u306e\u307f\n            })\n            -&gt;leftJoin('users as comment_users', 'comments.user_id', '=', 'comment_users.id')\n            -&gt;leftJoin('users as authors', 'articles.user_id', '=', 'authors.id')\n            -&gt;where('articles.id', $id)\n            -&gt;select(\n                'articles.*',\n                'authors.name as author_name',\n                'comments.id as comment_id',\n                'comments.content as comment_content',\n                'comment_users.name as commenter_name',\n                'comments.created_at as comment_date'\n            )\n            -&gt;get();\n\n        \/\/ \u30b3\u30e1\u30f3\u30c8\u3092\u30b0\u30eb\u30fc\u30d7\u5316\u3057\u3066\u6574\u7406\n        $comments = $article-&gt;map(function($item) {\n            return [\n                'id' =&gt; $item-&gt;comment_id,\n                'content' =&gt; $item-&gt;comment_content,\n                'user_name' =&gt; $item-&gt;commenter_name,\n                'created_at' =&gt; $item-&gt;comment_date\n            ];\n        })-&gt;filter(function($comment) {\n            return !is_null($comment['id']);\n        });\n\n        return view('blog.show', compact('article', 'comments'));\n    }\n}<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5b9f\u88c5\u4f8b\u306f\u3001\u5b9f\u969b\u306e\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306e\u8981\u4ef6\u306b\u5fdc\u3058\u3066\u30ab\u30b9\u30bf\u30de\u30a4\u30ba\u3057\u3066\u4f7f\u7528\u3067\u304d\u307e\u3059\u3002\u7279\u306b\u4ee5\u4e0b\u306e\u70b9\u306b\u6ce8\u610f\u3057\u3066\u5b9f\u88c5\u3092\u884c\u3046\u3053\u3068\u3092\u304a\u52e7\u3081\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u8003\u616e<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5fc5\u8981\u306a\u30ab\u30e9\u30e0\u306e\u307f\u3092\u9078\u629e<\/li>\n\n\n\n<li>\u9069\u5207\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8a2d\u5b9a<\/li>\n\n\n\n<li>\u5927\u91cf\u30c7\u30fc\u30bf\u306e\u5834\u5408\u306f\u30da\u30fc\u30b8\u30cd\u30fc\u30b7\u30e7\u30f3\u306e\u5b9f\u88c5<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4fdd\u5b88\u6027\u306e\u5411\u4e0a<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30af\u30a8\u30ea\u30d3\u30eb\u30c0\u30fc\u3068Eloquent\u306e\u9069\u5207\u306a\u4f7f\u3044\u5206\u3051<\/li>\n\n\n\n<li>\u8907\u96d1\u306a\u30af\u30a8\u30ea\u306f\u30b5\u30fc\u30d3\u30b9\u30af\u30e9\u30b9\u306b\u5206\u96e2<\/li>\n\n\n\n<li>\u5171\u901a\u51e6\u7406\u306f\u30b9\u30b3\u30fc\u30d7\u3068\u3057\u3066\u5b9f\u88c5<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u306e\u78ba\u4fdd<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e6\u30fc\u30b6\u30fc\u5165\u529b\u5024\u306e\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3<\/li>\n\n\n\n<li>SQL\u30a4\u30f3\u30b8\u30a7\u30af\u30b7\u30e7\u30f3\u5bfe\u7b56<\/li>\n\n\n\n<li>\u9069\u5207\u306a\u30a2\u30af\u30bb\u30b9\u5236\u5fa1\u306e\u5b9f\u88c5<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-45\">LEFT JOIN\u306e\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-46\">\u30b5\u30d6\u30af\u30a8\u30ea\u3068LEFT JOIN\u306e\u7d44\u307f\u5408\u308f\u305b\u65b9<\/h3>\n\n\n\n<p>\u30b5\u30d6\u30af\u30a8\u30ea\u3068LEFT JOIN\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u8907\u96d1\u306a\u6761\u4ef6\u3067\u306e\u96c6\u8a08\u3084\u5206\u6790\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-47\">\u6700\u65b0\u30c7\u30fc\u30bf\u306e\u53d6\u5f97<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5404\u30e6\u30fc\u30b6\u30fc\u306e\u6700\u65b0\u306e\u6ce8\u6587\u60c5\u5831\u3092\u53d6\u5f97\n$users = DB::table('users')\n    -&gt;leftJoin(DB::raw('(\n        SELECT \n            user_id,\n            MAX(created_at) as latest_order_date,\n            COUNT(*) as total_orders\n        FROM orders\n        GROUP BY user_id\n    ) as order_stats'), 'users.id', '=', 'order_stats.user_id')\n    -&gt;select(\n        'users.*',\n        'order_stats.latest_order_date',\n        'order_stats.total_orders'\n    )\n    -&gt;get();\n\n\/\/ \u3088\u308a\u8907\u96d1\u306a\u6761\u4ef6\u3067\u306e\u96c6\u8a08\n$productStats = DB::table('products')\n    -&gt;leftJoin(DB::raw('(\n        SELECT \n            product_id,\n            AVG(CASE WHEN created_at &gt;= DATE_SUB(NOW(), INTERVAL 30 DAY)\n                THEN rating ELSE NULL END) as recent_rating,\n            AVG(rating) as overall_rating,\n            COUNT(*) as total_reviews\n        FROM reviews\n        GROUP BY product_id\n    ) as review_stats'), 'products.id', '=', 'review_stats.product_id')\n    -&gt;select(\n        'products.*',\n        'review_stats.recent_rating',\n        'review_stats.overall_rating',\n        'review_stats.total_reviews'\n    )\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-48\">\u671f\u9593\u3054\u3068\u306e\u96c6\u8a08<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u6708\u6b21\u58f2\u4e0a\u306e\u6bd4\u8f03\n$monthlyComparison = DB::table('orders')\n    -&gt;leftJoin(DB::raw('(\n        SELECT \n            YEAR(created_at) as year,\n            MONTH(created_at) as month,\n            SUM(amount) as total_amount\n        FROM orders\n        WHERE created_at &gt;= DATE_SUB(NOW(), INTERVAL 1 YEAR)\n        GROUP BY YEAR(created_at), MONTH(created_at)\n    ) as last_year'), function($join) {\n        $join-&gt;on(DB::raw('MONTH(orders.created_at)'), '=', 'last_year.month')\n             -&gt;on(DB::raw('YEAR(orders.created_at)'), '=', DB::raw('last_year.year + 1'));\n    })\n    -&gt;select(\n        DB::raw('MONTH(orders.created_at) as month'),\n        DB::raw('SUM(orders.amount) as current_amount'),\n        'last_year.total_amount as last_year_amount'\n    )\n    -&gt;whereYear('orders.created_at', '=', DB::raw('YEAR(CURRENT_DATE())'))\n    -&gt;groupBy(DB::raw('MONTH(orders.created_at)'))\n    -&gt;get();<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-49\">Eloquent\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3068\u306e\u4f75\u7528\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>Eloquent\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3068LEFT JOIN\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u67d4\u8edf\u306a\u30c7\u30fc\u30bf\u53d6\u5f97\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-50\">\u9ad8\u5ea6\u306a\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u5b9a\u7fa9<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ User\u30e2\u30c7\u30eb\nclass User extends Model\n{\n    \/\/ \u6700\u65b0\u306e\u6ce8\u6587\u60c5\u5831\u3092\u53d6\u5f97\u3059\u308b\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\n    public function latestOrder()\n    {\n        return $this-&gt;hasOne(Order::class)\n            -&gt;latest()\n            -&gt;withDefault(['status' =&gt; '\u306a\u3057']);\n    }\n\n    \/\/ \u904e\u53bb30\u65e5\u9593\u306e\u6ce8\u6587\u7d71\u8a08\n    public function orderStats()\n    {\n        return $this-&gt;hasOne(OrderStat::class)\n            -&gt;selectRaw('\n                user_id,\n                COUNT(*) as order_count,\n                SUM(amount) as total_amount,\n                AVG(amount) as avg_amount\n            ')\n            -&gt;whereRaw('created_at &gt;= DATE_SUB(NOW(), INTERVAL 30 DAY)')\n            -&gt;groupBy('user_id');\n    }\n}\n\n\/\/ \u5b9f\u88c5\u4f8b\nclass UserController extends Controller\n{\n    public function index()\n    {\n        $users = User::query()\n            -&gt;with(['latestOrder', 'orderStats'])\n            -&gt;leftJoin('user_profiles', 'users.id', '=', 'user_profiles.user_id')\n            -&gt;select('users.*', 'user_profiles.bio')\n            -&gt;get();\n\n        return view('users.index', compact('users'));\n    }\n}<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-51\">\u52d5\u7684\u306a\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u671f\u9593\u3092\u6307\u5b9a\u3057\u3066\u6ce8\u6587\u7d71\u8a08\u3092\u53d6\u5f97\nclass Order extends Model\n{\n    public function scopeStatsByPeriod($query, $startDate, $endDate)\n    {\n        return $query-&gt;selectRaw('\n            user_id,\n            COUNT(*) as order_count,\n            SUM(amount) as total_amount,\n            AVG(amount) as avg_amount\n        ')\n        -&gt;whereBetween('created_at', [$startDate, $endDate])\n        -&gt;groupBy('user_id');\n    }\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$users = User::query()\n    -&gt;leftJoinSub(\n        Order::statsByPeriod(\n            now()-&gt;subDays(30),\n            now()\n        ),\n        'order_stats',\n        'users.id',\n        '=',\n        'order_stats.user_id'\n    )\n    -&gt;select(\n        'users.*',\n        'order_stats.order_count',\n        'order_stats.total_amount',\n        'order_stats.avg_amount'\n    )\n    -&gt;get();<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-52\">\u9ad8\u5ea6\u306a\u96c6\u8a08\u30c6\u30af\u30cb\u30c3\u30af<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u8907\u6570\u306e\u96c6\u8a08\u3092\u540c\u6642\u306b\u5b9f\u884c\nclass ProductController extends Controller\n{\n    public function analytics()\n    {\n        $products = Product::query()\n            -&gt;leftJoinSub(\n                Review::selectRaw('\n                    product_id,\n                    AVG(rating) as avg_rating,\n                    COUNT(*) as review_count\n                ')\n                -&gt;groupBy('product_id'),\n                'review_stats',\n                'products.id',\n                '=',\n                'review_stats.product_id'\n            )\n            -&gt;leftJoinSub(\n                OrderItem::selectRaw('\n                    product_id,\n                    SUM(quantity) as total_sold,\n                    SUM(quantity * price) as total_revenue\n                ')\n                -&gt;groupBy('product_id'),\n                'sales_stats',\n                'products.id',\n                '=',\n                'sales_stats.product_id'\n            )\n            -&gt;select(\n                'products.*',\n                'review_stats.avg_rating',\n                'review_stats.review_count',\n                'sales_stats.total_sold',\n                'sales_stats.total_revenue'\n            )\n            -&gt;get();\n\n        return view('products.analytics', compact('products'));\n    }\n}<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af\u3092\u6d3b\u7528\u3059\u308b\u969b\u306e\u91cd\u8981\u306a\u30dd\u30a4\u30f3\u30c8\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u7d50\u679c\u306f\u4e00\u6642\u30c6\u30fc\u30d6\u30eb\u3068\u3057\u3066\u30ad\u30e3\u30c3\u30b7\u30e5\u3055\u308c\u308b<\/li>\n\n\n\n<li>\u9069\u5207\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u306e\u8a2d\u5b9a\u304c\u91cd\u8981<\/li>\n\n\n\n<li>\u5927\u91cf\u30c7\u30fc\u30bf\u306e\u5834\u5408\u306f\u30c1\u30e3\u30f3\u30af\u51e6\u7406\u3092\u691c\u8a0e<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30af\u30a8\u30ea\u306e\u53ef\u8aad\u6027<\/strong><\/li>\n<\/ol>\n\n\n\n<ul 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