{"id":8417,"date":"2026-05-18T12:19:06","date_gmt":"2026-05-18T03:19:06","guid":{"rendered":"https:\/\/since2020.jp\/media\/?p=8417"},"modified":"2026-05-18T12:19:39","modified_gmt":"2026-05-18T03:19:39","slug":"subquery_exec","status":"publish","type":"post","link":"https:\/\/since2020.jp\/media\/subquery_exec\/","title":{"rendered":"SQL\u30b5\u30d6\u30af\u30a8\u30ea\u3068\u306f\uff1f\u301c\u5b9f\u884c\u9806\u3054\u3068\u306b\u89e3\u8aac\u301c"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">\u306f\u3058\u3081\u306b<\/h2>\n\n\n\n<p>SQL\u306b\u304a\u3051\u308b\u30b5\u30d6\u30af\u30a8\u30ea\u3068\u306f\u3001\u5225\u306eSQL\u6587\u306e\u5185\u90e8\u306b\u57cb\u3081\u8fbc\u307e\u308c\u305fSELECT\u6587\u306e\u3053\u3068\u3067\u3059\u3002\u5916\u5074\u306e\u30af\u30a8\u30ea\u304c\u5185\u5074\u306e\u30af\u30a8\u30ea\u306e\u7d50\u679c\u3092\u5229\u7528\u3057\u3066\u8907\u96d1\u306a\u51e6\u7406\u3092\u884c\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u4f7f\u7528\u30c7\u30fc\u30bf<\/h2>\n\n\n\n<p>Employees\u30c6\u30fc\u30d6\u30eb<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"658\" height=\"353\" src=\"https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.45.48.png\" alt=\"\" class=\"wp-image-8425\" srcset=\"https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.45.48.png 658w, https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.45.48-300x161.png 300w\" sizes=\"(max-width: 658px) 100vw, 658px\" \/><\/figure>\n\n\n\n<p>Departments\u30c6\u30fc\u30d6\u30eb<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"413\" height=\"179\" src=\"https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.46.16.png\" alt=\"\" class=\"wp-image-8426\" srcset=\"https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.46.16.png 413w, https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.46.16-300x130.png 300w\" sizes=\"(max-width: 413px) 100vw, 413px\" \/><\/figure>\n\n\n\n<p>Orders\u30c6\u30fc\u30d6\u30eb<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"650\" height=\"349\" src=\"https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.51.14.png\" alt=\"\" class=\"wp-image-8427\" srcset=\"https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.51.14.png 650w, https:\/\/since2020.jp\/media\/wp-content\/uploads\/2026\/05\/\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8-2026-04-14-12.51.14-300x161.png 300w\" sizes=\"(max-width: 650px) 100vw, 650px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Where\u53e5\u306b\u304a\u3051\u308b\u4f7f\u7528<\/h2>\n\n\n\n<p>\u6700\u3082\u4e00\u822c\u7684\u306a\u4f7f\u3044\u65b9\u3067Where\u53e5\u3067\u4f7f\u3046\u5834\u5408\u306f\u6761\u4ef6\u306b\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3063\u3066\u30d5\u30a3\u30eb\u30bf\u30ea\u30f3\u30b0\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4f8b\u3048\u3070\u5e73\u5747\u7d66\u4e0e\u3088\u308a\u9ad8\u3044\u793e\u54e1\u3092\u53d6\u5f97\u3059\u308b\u5834\u5408<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT name, salary\nFROM employees\nWHERE salary &gt; (SELECT AVG(salary) FROM employees);<\/code><\/pre>\n\n\n\n<p>\u30b5\u30d6\u30af\u30a8\u30ea\u306eSELECT AVG(salary) FROM employees\u304c\u5b9f\u884c\u3055\u308c\u30e1\u30a4\u30f3\u30af\u30a8\u30ea\u304c\u5b9f\u884c\u3055\u308c\u307e\u3059<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>AVG<\/th><\/tr><tr><td>522000.0000<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>name<\/th><th>salary<\/th><\/tr><tr><td>\u4f50\u85e4\u5065\u4e00<\/td><td>610000<\/td><\/tr><tr><td>\u9ad8\u6a4b\u7fd4<\/td><td>530000<\/td><\/tr><tr><td>\u4f0a\u85e4\u76f4\u6a39<\/td><td>700000<\/td><\/tr><tr><td>\u5c0f\u6797\u7531\u7f8e<\/td><td>550000<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea<\/h2>\n\n\n\n<p>\u5148\u307b\u3069\u306e\u30af\u30a8\u30ea\u306f\u3059\u3079\u3066\u306e\u884c\u3067\u540c\u3058\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u4f7f\u3063\u3066\u3044\u305f\u304c\u3001\u76f8\u95a2\u526f\u554f\u3044\u5408\u308f\u305b\u306f\u30e1\u30a4\u30f3\u30af\u30a8\u30ea\u306e\u5024\u3092\u53c2\u7167\u3059\u308b\u3053\u3068\u3092\u53ef\u80fd\u306b\u3059\u308b\u3002\u5916\u5074\u306e\u884c\u304c1\u884c\u51e6\u7406\u3055\u308c\u308b\u305f\u3073\u306b\u3001\u305d\u306e\u884c\u306e\u5024\u3092\u4f7f\u3063\u3066\u526f\u554f\u5408\u305b\u304c\u5b9f\u884c\u3055\u308c\u307e\u3059\u3002\u3064\u307e\u308a\u300c\u884c\u3054\u3068\u306b\u554f\u3044\u5408\u308f\u305b\u5185\u5bb9\u304c\u5909\u308f\u308b\u300d\u306e\u304c\u7279\u5fb4\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u300c\u81ea\u5206\u3068\u540c\u3058\u90e8\u7f72\u306e\u5e73\u5747\u7d66\u4e0e\u300d\u3088\u308a\u9ad8\u3044\u793e\u54e1\u3092\u53d6\u5f97\u3059\u308b\u5834\u5408<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT e.name, e.dept_id, e.salary\nFROM employees e\nWHERE e.salary &gt; (\n  SELECT AVG(e2.salary) FROM employees e2 WHERE e2.dept_id = e.dept_id);<\/code><\/pre>\n\n\n\n<p>WHERE e2.dept_id = e.dept_id\u3067\u5916\u5074\u306e\u884c\u3092\u53c2\u7167\u3057\u884c\u3054\u3068\u306b\u7570\u306a\u308b\u30af\u30a8\u30ea\u306b\u306a\u308a\u307e\u3059\u3002\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u81ea\u5206\u3068\u540c\u3058\u90e8\u7f72\u306e\u5e73\u5747\u7d66\u4e0e\u304c\u5c0e\u51fa\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">dept_id = 1\u306e\u6642\u306e\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>AVG(salary)<\/th><\/tr><tr><td>595000.0000<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>name<\/th><th>dept_id<\/th><th>salary<\/th><\/tr><tr><td>\u4f50\u85e4\u5065\u4e00<\/td><td>1<\/td><td>610000<\/td><\/tr><tr><td>\u5c71\u7530\u7f8e\u54b2<\/td><td>3<\/td><td>450000<\/td><\/tr><tr><td>\u9ad8\u6a4b\u7fd4<\/td><td>2<\/td><td>530000<\/td><\/tr><tr><td>\u4f0a\u85e4\u76f4\u6a39<\/td><td>1<\/td><td>700000<\/td><\/tr><tr><td>\u52a0\u85e4\u8aa0<\/td><td>3<\/td><td>470000<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">FROM\u53e5\u3067\u306e\u4f7f\u7528<\/h2>\n\n\n\n<p>\u526f\u554f\u5408\u305b\u306e\u7d50\u679c\u3092\u4eee\u60f3\u7684\u306a\u30c6\u30fc\u30d6\u30eb\u3068\u3057\u3066\u6271\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u53d7\u6ce8\u4ef6\u6570\u3068\u53d7\u6ce8\u5408\u8a08\u984d\u3092\u793e\u54e1\u60c5\u5831\u3068\u4e26\u3079\u3066\u8868\u793a<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT e.name, t.order_count, t.total_amount\nFROM employees e\nJOIN (\n  SELECT emp_id,\n         COUNT(*) AS order_count,\n         SUM(amount) AS total_amount\n  FROM orders\n  GROUP BY emp_id\n) AS t ON e.emp_id = t.emp_id;<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u30b5\u30d6\u30af\u30a8\u30ea<\/h3>\n\n\n\n<p>\u30af\u30a8\u30ea\u5168\u4f53\u304c\u8907\u96d1\u306a\u305f\u3081\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u53d7\u6ce8\u4ef6\u6570\u3068\u53d7\u6ce8\u5408\u8a08\u984d\u3092\u6c42\u3081\u307e\u3059<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT emp_id,\n      COUNT(*) AS order_count,\n       SUM(amount) AS total_amount\nFROM orders\nGROUP BY emp_id<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>emp_id<\/th><th>order_count<\/th><th>total_amount<\/th><\/tr><tr><td>2<\/td><td>4<\/td><td>4350000<\/td><\/tr><tr><td>5<\/td><td>3<\/td><td>8100000<\/td><\/tr><tr><td>8<\/td><td>3<\/td><td>3600000<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<p>\u793e\u54e1\u306e\u540d\u524d\u304c\u5fc5\u8981\u306a\u305f\u3081employee\u30c6\u30fc\u30d6\u30eb\u3068\u7d50\u5408<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>name<\/th><th>order_count<\/th><th>total_amout<\/th><\/tr><tr><td>\u9234\u6728\u82b1\u5b50<\/td><td>4<\/td><td>4350000<\/td><\/tr><tr><td>\u9ad8\u6a4b\u7fd4<\/td><td>3<\/td><td>8100000<\/td><\/tr><tr><td>\u4e2d\u6751\u5927\u8f14<\/td><td>3<\/td><td>3600000<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">SELECT\u53e5\u3067\u306e\u4f7f\u7528<\/h2>\n\n\n\n<p>\u8907\u96d1\u306a\u30ab\u30e9\u30e0\u8a08\u7b97\u3092SELECT\u53e5\u5185\u3067\u5b8c\u7d50\u3067\u304d\u307e\u3059<\/p>\n\n\n\n<p>\u5404\u793e\u54e1\u306e\u540d\u524d\u3068\u3001\u305d\u306e\u793e\u54e1\u306e\u53d7\u6ce8\u4ef6\u6570\u3092\u4e26\u3079\u3066\u8868\u793a<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT e.name,\n       e.salary,\n       (SELECT COUNT(*) FROM orders o WHERE o.emp_id = e.emp_id) AS order_count\nFROM employees e;<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">emp_id=1\u306e\u6642\u306e\u30b5\u30d6\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<p>SELECT\u53e5\u3067\u4f7f\u308f\u308c\u308b\u30b5\u30d6\u30af\u30a8\u30ea\u306f\u30ec\u30b3\u30fc\u30c91\u884c\u306b\u5bfe\u3057\u30661\u56de\u5b9f\u884c\u3055\u308c\u308b\u76f8\u95a2\u30b5\u30d6\u30af\u30a8\u30ea\u3067\u3042\u308b\u306e\u3067<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>name<\/th><th>salary<\/th><th>order_count<\/th><\/tr><tr><td>\u7530\u4e2d\u592a\u90ce<\/td><td>520000<\/td><td>0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>name<\/th><th>salary<\/th><th>order_count<\/th><\/tr><tr><td>\u7530\u4e2d\u592a\u90ce<\/td><td>520000<\/td><td>0<\/td><\/tr><tr><td>\u9234\u6728\u82b1\u5b50<\/td><td>480000<\/td><td>4<\/td><\/tr><tr><td>\u4f50\u85e4\u5065\u4e00<\/td><td>610000<\/td><td>0<\/td><\/tr><tr><td>\u5c71\u7530\u7f8e\u54b2<\/td><td>450000<\/td><td>0<\/td><\/tr><tr><td>\u9ad8\u6a4b\u7fd4<\/td><td>530000<\/td><td>3<\/td><\/tr><tr><td>\u4f0a\u85e4\u76f4\u6a39<\/td><td>700000<\/td><td>0<\/td><\/tr><tr><td>\u6e21\u8fba\u3042\u304b\u308a<\/td><td>420000<\/td><td>0<\/td><\/tr><tr><td>\u4e2d\u6751\u5927\u8f14<\/td><td>490000<\/td><td>3<\/td><\/tr><tr><td>\u5c0f\u6797\u7531\u7f8e<\/td><td>550000<\/td><td>0<\/td><\/tr><tr><td>\u52a0\u85e4\u8aa0<\/td><td>470000<\/td><td>0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">\u307e\u3068\u3081<\/h2>\n\n\n\n<p>\u30b5\u30d6\u30af\u30a8\u30ea\u306fSQL\u5b66\u7fd2\u306e\u4e2d\u3067\u3082\u7279\u306b\u96e3\u3057\u3044\u5206\u91ce\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u3057\u304b\u3057\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u7406\u89e3\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308c\u3070\u8907\u96d1\u306a\u30af\u30a8\u30ea\u3082\u7c21\u6f54\u306b\u8a18\u8ff0\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u662f\u975e\u3001\u5b9f\u6226\u3067\u3082\u6d3b\u7528\u3057\u3066\u696d\u52d9\u3092\u52b9\u7387\u5316\u3057\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n\n\n\n\n","protected":false},"excerpt":{"rendered":"<p>\u306f\u3058\u3081\u306b SQL\u306b\u304a\u3051\u308b\u30b5\u30d6\u30af\u30a8\u30ea\u3068\u306f\u3001\u5225\u306eSQL\u6587\u306e\u5185\u90e8\u306b\u57cb\u3081\u8fbc\u307e\u308c\u305fSELECT\u6587\u306e\u3053\u3068\u3067\u3059\u3002\u5916\u5074\u306e\u30af\u30a8\u30ea\u304c\u5185\u5074\u306e\u30af\u30a8\u30ea\u306e\u7d50\u679c\u3092\u5229\u7528\u3057\u3066\u8907\u96d1\u306a\u51e6\u7406\u3092\u884c\u3044\u307e\u3059\u3002 \u4f7f\u7528\u30c7\u30fc\u30bf Employees\u30c6\u30fc\u30d6\u30eb Departme [&hellip;]<\/p>\n","protected":false},"author":14,"featured_media":8422,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"content-type":"","swell_btn_cv_data":"","footnotes":"","_wp_rev_ctl_limit":""},"categories":[1251],"tags":[148,673,39],"class_list":["post-8417","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-data-analysis","tag-sql","tag-673","tag-39"],"_links":{"self":[{"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/posts\/8417","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/users\/14"}],"replies":[{"embeddable":true,"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/comments?post=8417"}],"version-history":[{"count":4,"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/posts\/8417\/revisions"}],"predecessor-version":[{"id":8429,"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/posts\/8417\/revisions\/8429"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/media\/8422"}],"wp:attachment":[{"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/media?parent=8417"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/categories?post=8417"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/since2020.jp\/media\/wp-json\/wp\/v2\/tags?post=8417"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}