{"id":7738,"date":"2019-09-26T10:00:57","date_gmt":"2019-09-26T01:00:57","guid":{"rendered":"https:\/\/www.gigas-jp.com\/appnews\/?p=7738"},"modified":"2019-09-24T13:02:39","modified_gmt":"2019-09-24T04:02:39","slug":"mysql-1%e5%af%be%e5%a4%9a%e3%81%a7%e7%b4%90%e3%81%a5%e3%81%8f%e3%83%86%e3%83%bc%e3%83%96%e3%83%ab%e3%81%8c%e8%a4%87%e6%95%b0%e3%81%82%e3%81%a3%e3%81%9f%e5%a0%b4%e5%90%88%e3%81%ae%e3%80%8cgroup_conca","status":"publish","type":"post","link":"https:\/\/www.gigas-jp.com\/appnews\/archives\/7738","title":{"rendered":"[MySQL] 1\u5bfe\u591a\u3067\u7d10\u3065\u304f\u30c6\u30fc\u30d6\u30eb\u304c\u8907\u6570\u3042\u3063\u305f\u5834\u5408\u306e\u300cgroup_concat\u300d"},"content":{"rendered":"\n<p>\u4eca\u56de\u306f1\u5bfe\u591a\u3067\u7d10\u3065\u304f\u30c6\u30fc\u30d6\u30eb\u304c\u8907\u6570\u3042\u3063\u305f\u5834\u5408\u306e\u300cgroup_concat\u300d\u306e\u4f7f\u7528\u65b9\u6cd5\u306b\u3064\u3044\u3066\u3067\u3059\u3002<\/p>\n\n\n\n<!--more-->\n\n\n\n<p>\u4ee5\u4e0b\u306e\u3088\u3046\u306b3\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u304c\u3042\u308a\u307e\u3059\u3002<br> \u5404\u30c6\u30fc\u30d6\u30eb\u306fclass\u30c6\u30fc\u30d6\u30eb\u306eid\u3092key\u3068\u3057\u3066\u7d10\u4ed8\u3051\u3089\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p><br><br><strong>class\u30c6\u30fc\u30d6\u30eb<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"332\" height=\"177\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/classtb.png\" alt=\"\" class=\"wp-image-7740\"\/><\/figure>\n\n\n\n<p><br><br><strong>student\u30c6\u30fc\u30d6\u30eb<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"395\" height=\"211\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/studenttb.png\" alt=\"\" class=\"wp-image-7741\"\/><\/figure>\n\n\n\n<p><br><br><strong>item\u30c6\u30fc\u30d6\u30eb<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"390\" height=\"213\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/itemtb.png\" alt=\"\" class=\"wp-image-7742\"\/><\/figure>\n\n\n\n<p><br><br>\u307e\u305a\u306f\u5404\u30af\u30e9\u30b9\u306b\u5c5e\u3057\u3066\u3044\u308b\u751f\u5f92\u540d\u3092\u8abf\u3079\u308b\u305f\u3081\u306b<br> \u300cgroup_concat\u300d\u3092\u4f7f\u7528\u3057\u3066\u4ee5\u4e0b\u306eSQL\u3092\u4f5c\u6210\u3057\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select\n  a.id\n  , a.classname\n  , group_concat(b.name) \nfrom\n  class a \n  left join students b \n    on a.id = b.classid \ngroup by\n  a.id;<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8a18\u306e\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"492\" height=\"437\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/concat_student.png\" alt=\"\" class=\"wp-image-7744\"\/><\/figure>\n\n\n\n<p>\u3053\u308c\u3067\u5404\u30af\u30e9\u30b9\u306b\u5c5e\u3059\u308b\u751f\u5f92\u304c\u308f\u304b\u308a\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<p>\u6b21\u306b\u5404\u30af\u30e9\u30b9\u304c\u6240\u6709\u3059\u308b\u5099\u54c1\u3092\u8abf\u3079\u308b\u305f\u3081\u306b<br> \u4ee5\u4e0b\u306eSQL\u3092\u4f5c\u6210\u3057\u307e\u3057\u305f\u3002<br> \u3053\u3061\u3089\u3082\u300cgroup_concat\u300d\u3092\u4f7f\u7528\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select\n  a.id\n  , a.classname\n  , group_concat(b.name) \nfrom\n  class a \n  left join items b \n    on a.id = b.classid \ngroup by\n  a.id;<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8a18\u306e\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"495\" height=\"416\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/concat_items.png\" alt=\"\" class=\"wp-image-7745\"\/><\/figure>\n\n\n\n<p>\u3053\u308c\u3067\u5404\u30af\u30e9\u30b9\u304c\u6240\u6709\u3059\u308b\u5099\u54c1\u304c\u308f\u304b\u308a\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<p>\u305d\u308c\u3067\u306f\u3001\u5404\u30af\u30e9\u30b9\u306b\u5c5e\u3059\u308b\u751f\u5f92\u3068\u5404\u30af\u30e9\u30b9\u304c\u6240\u6709\u3059\u308b\u5099\u54c1\u3092<br>\n\u540c\u6642\u306b\u8abf\u3079\u305f\u3044\u5834\u5408\u3001\u3069\u3046\u3059\u308c\u3070\u3044\u3044\u3067\u3057\u3087\u3046\u304b\u3002<\/p>\n\n\n\n<p>\u5358\u7d14\u306b\u4e0a\u8a18\u306e2\u3064\u306eSQL\u3092\u30df\u30c3\u30af\u30b9\u3057\u305f\u3089\u3069\u3046\u306a\u308b\u304b\u8a66\u3057\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select\n  a.id\n  , a.classname\n  , group_concat(c.name)\n  , group_concat(b.name) \nfrom\n  class a \n  left join items b \n    on a.id = b.classid \n  left join students c \n    on a.id = c.classid \ngroup by\n  a.id;<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8a18\u306e\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"778\" height=\"475\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/concat_both_ng.png\" alt=\"\" class=\"wp-image-7746\"\/><\/figure>\n\n\n\n<p>\u51fa\u529b\u7d50\u679c\u306b\u540c\u3058\u540d\u79f0\u304c\u91cd\u8907\u3057\u3066\u8868\u793a\u3055\u308c\u3066\u3057\u307e\u3044\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<p>\u91cd\u8907\u7b87\u6240\u3092\u4e00\u610f\u306b\u3059\u308b\u306b\u306f\u300cdistinct\u300d\u3092\u4f7f\u7528\u3059\u308c\u3070\u6539\u5584\u3067\u304d\u308b\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u3002<br> \u4e0a\u8a18\u306eSQL\u306b\u300cdistinct\u300d\u3092\u8ffd\u52a0\u3057\u3066\u51fa\u529b\u3057\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select\n  a.id\n  , a.classname\n  , group_concat(distinct c.name)\n  , group_concat(distinct b.name) \nfrom\n  class a \n  left join items b \n    on a.id = b.classid \n  left join students c \n    on a.id = c.classid \ngroup by\n  a.id;<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8a18\u306e\u5b9f\u884c\u7d50\u679c<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"778\" height=\"471\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/concat_both_distinct.png\" alt=\"\" class=\"wp-image-7755\"\/><\/figure>\n\n\n\n<p>\u3046\u307e\u304f\u3044\u3063\u305f\u3088\u3046\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u6b21\u306bdistinct\u3092\u4f7f\u7528\u3057\u306a\u3044\u3067\u5b9f\u73fe\u3059\u308b\u65b9\u6cd5\u306f\u306a\u3044\u304b\u3092\u691c\u8a0e\u3057\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<p>\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3063\u3066\u51fa\u529b\u3055\u305b\u305f\u5834\u5408\u306f\u3069\u3046\u3067\u3057\u3087\u3046\u304b\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0b\u3001\u8a66\u3057\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select\n  a.id\n  , a.classname\n  , group_concat(distinct b.name) \nfrom\n  class a \n  left join students b \n    on a.id = b.classid \ngroup by\n  a.id;<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8a18\u306eSQL\u3092\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u7528\u3059\u308bSQL\u306b<br> \u5909\u5f62\u3057\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select\n  a.id\n  , a.classname\n  , ( \n    select\n      group_concat(name) \n    from\n      students \n    where\n      classid = a.id\n  ) studentname \nfrom\n  class a;\n<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8a18\u306e\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"465\" height=\"469\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/sub1.png\" alt=\"\" class=\"wp-image-7756\"\/><\/figure>\n\n\n\n<p>\u5909\u5f62\u524d\u3068\u540c\u3058\u51fa\u529b\u7d50\u679c\u3067\u51fa\u529b\u3067\u304d\u308b\u3053\u3068\u304c\u308f\u304b\u308a\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<p>\u6b21\u306b\u3001\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3063\u305f\u65b9\u6cd5\u3067\u3001\u5099\u54c1\u3092\u78ba\u8a8d\u3059\u308b\u305f\u3081\u306e<br> SQL\u3092\u8ffd\u52a0\u3057\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select\n  a.id\n  , a.classname\n  , ( \n    select\n      group_concat(name) \n    from\n      students \n    where\n      classid = a.id\n  ) studentname\n  , ( \n    select\n      group_concat(name) \n    from\n      items \n    where\n      classid = a.id\n  ) itemname \nfrom\n  class a;<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8a18\u306e\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" width=\"668\" height=\"605\" src=\"\/appnews\/wp-content\/uploads\/sites\/4\/2019\/09\/sub2.png\" alt=\"\" class=\"wp-image-7757\"\/><\/figure>\n\n\n\n<p>\u3053\u306e\u65b9\u6cd5\u3067\u7d50\u679c\u304c\u91cd\u8907\u3059\u308b\u3053\u3068\u306a\u304f\u6b63\u3057\u3044\u7d50\u679c\u304c\u51fa\u529b\u3067\u304d\u307e\u3057\u305f\u3002<br>\n\u30b5\u30d6\u30af\u30a8\u30ea\u3092\u4f7f\u3063\u3066\u5bfe\u5fdc\u3059\u308b\u3053\u3068\u3082\u53ef\u80fd\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0a\u30011\u5bfe\u591a\u3067\u7d10\u3065\u304fTable\u304c\u8907\u6570\u3042\u3063\u305f\u5834\u5408\u306e\u300cgroup_concat\u300d<br> \u306e\u4f7f\u7528\u65b9\u6cd5\u306b\u3064\u3044\u3066\u7d39\u4ecb\u3044\u305f\u3057\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<p><br>\u6728\u66dc\u65e5\u62c5\u5f53: nishida<\/p>\n<div class='wp_social_bookmarking_light'>\n            <div class=\"wsbl_google_plus_one\"><g:plusone size=\"medium\" annotation=\"none\" href=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/7738\" ><\/g:plusone><\/div>\n            <div class=\"wsbl_hatena_button\"><a href=\"\/\/b.hatena.ne.jp\/entry\/https:\/\/www.gigas-jp.com\/appnews\/archives\/7738\" class=\"hatena-bookmark-button\" data-hatena-bookmark-title=\"[MySQL] 1\u5bfe\u591a\u3067\u7d10\u3065\u304f\u30c6\u30fc\u30d6\u30eb\u304c\u8907\u6570\u3042\u3063\u305f\u5834\u5408\u306e\u300cgroup_concat\u300d\" data-hatena-bookmark-layout=\"standard\" title=\"\u3053\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3092\u306f\u3066\u306a\u30d6\u30c3\u30af\u30de\u30fc\u30af\u306b\u8ffd\u52a0\"> <img src=\"\/\/b.hatena.ne.jp\/images\/entry-button\/button-only@2x.png\" alt=\"\u3053\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3092\u306f\u3066\u306a\u30d6\u30c3\u30af\u30de\u30fc\u30af\u306b\u8ffd\u52a0\" width=\"20\" height=\"20\" style=\"border: none;\" \/><\/a><script type=\"text\/javascript\" src=\"\/\/b.hatena.ne.jp\/js\/bookmark_button.js\" charset=\"utf-8\" async=\"async\"><\/script><\/div>\n            <div class=\"wsbl_twitter\"><a href=\"https:\/\/twitter.com\/share\" class=\"twitter-share-button\" data-url=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/7738\" data-text=\"[MySQL] 1\u5bfe\u591a\u3067\u7d10\u3065\u304f\u30c6\u30fc\u30d6\u30eb\u304c\u8907\u6570\u3042\u3063\u305f\u5834\u5408\u306e\u300cgroup_concat\u300d\" data-via=\"GIGASJAPAN_APPS\" data-lang=\"ja\">Tweet<\/a><\/div>\n            <div class=\"wsbl_facebook_like\"><div id=\"fb-root\"><\/div><fb:like href=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/7738\" layout=\"button_count\" action=\"like\" width=\"100\" share=\"false\" show_faces=\"false\" ><\/fb:like><\/div>\n            <div class=\"wsbl_facebook_send\"><div id=\"fb-root\"><\/div><fb:send href=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/7738\" colorscheme=\"light\" ><\/fb:send><\/div>\n    <\/div>\n<br class='wp_social_bookmarking_light_clear' \/>\n","protected":false},"excerpt":{"rendered":"<p>\u4eca\u56de\u306f1\u5bfe\u591a\u3067\u7d10\u3065\u304f\u30c6\u30fc\u30d6\u30eb\u304c\u8907\u6570\u3042\u3063\u305f\u5834\u5408\u306e\u300cgroup_concat\u300d\u306e\u4f7f\u7528\u65b9\u6cd5\u306b\u3064\u3044\u3066\u3067\u3059\u3002<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[35],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts\/7738"}],"collection":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/comments?post=7738"}],"version-history":[{"count":10,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts\/7738\/revisions"}],"predecessor-version":[{"id":7762,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts\/7738\/revisions\/7762"}],"wp:attachment":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/media?parent=7738"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/categories?post=7738"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/tags?post=7738"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}