{"id":342,"date":"2018-07-18T18:35:47","date_gmt":"2018-07-18T09:35:47","guid":{"rendered":"http:\/\/www.fatware.jp\/?page_id=342"},"modified":"2018-07-19T09:44:36","modified_gmt":"2018-07-19T00:44:36","slug":"group_concat%e3%81%ae%e6%9c%80%e5%a4%a7%e6%96%87%e5%ad%97%e5%88%97%e9%95%b7%e3%81%a8concat","status":"publish","type":"page","link":"https:\/\/www.fatware.jp\/?page_id=342","title":{"rendered":"[SQL]GROUP_CONCAT\u306e\u6700\u5927\u6587\u5b57\u5217\u9577\u3068CONCAT"},"content":{"rendered":"<h2 id=\"head1\" class=\"revision-head\">group_concat\u306e\u6700\u5927\u9577\u8abf\u6574<\/h2>\n<p>\u4ee5\u4e0b\u3067\u3001\u30bb\u30c3\u30b7\u30e7\u30f3\u4e2d\u306e\u307f\u3067\u304d\u308b\u3002<\/p>\n<pre class=\"wiki-code wiki-lang\"><cite>maxlen<\/cite><code class=\"lang-sql:maxlen\">SESSION group_concat_max_len 100000;\r\n\r\n\r\nMariaDB [erm2]&gt; SHOW VARIABLES LIKE '%concat%';\r\n+----------------------+-------+\r\n| Variable_name | Value |\r\n+----------------------+-------+\r\n| group_concat_max_len | 1024 |\r\n+----------------------+-------+\r\n<\/code><\/pre>\n<p>\u3092\u5909\u3048\u3066\u3057\u307e\u3046\u3068\u3044\u3046\u306e\u3082\u3042\u308b\u3002<\/p>\n<h2 id=\"head2\" class=\"revision-head\">concat\u3059\u308b\u3068\u304d\u306bNULL\u3068\u7d50\u5408\u3059\u308b\u3068\u6d88\u3048\u308b\u554f\u984c<\/h2>\n<p>coalesce\uff08\uff09\u3067\u304f\u304f\u308c\u3070OK\u3002\u4ee5\u4e0b\u306e\u4f8b\u306f\u305d\u306e\u4e2d\u3067DATA2\u3092\uff08\uff09\u3067\u304f\u304f\u3063\u305f\u6587\u5b57\u5217\u3092\u51fa\u3057\u305f\u3044\u6a21\u69d8<\/p>\n<pre class=\"wiki-code wiki-lang\"><code class=\"lang-sql\"><span class=\"hljs-keyword\">SELECT<\/span> <span class=\"hljs-keyword\">CONCAT<\/span>(\r\n\r\n              DATA1,\r\n              <span class=\"hljs-keyword\">COALESCE<\/span>(\r\n                         <span class=\"hljs-keyword\">CONCAT<\/span>(<span class=\"hljs-string\">\" (\"<\/span>,DATA2,<span class=\"hljs-string\">\")\"<\/span>)\r\n                       ,<span class=\"hljs-string\">\"\"<\/span>)\r\n              )<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>group_concat\u306e\u6700\u5927\u9577\u8abf\u6574 \u4ee5\u4e0b\u3067\u3001\u30bb\u30c3\u30b7\u30e7\u30f3\u4e2d\u306e\u307f\u3067\u304d\u308b\u3002 maxl <a href=\"https:\/\/www.fatware.jp\/?page_id=342\" class=\"read-more\">\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":363,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-342","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.fatware.jp\/index.php?rest_route=\/wp\/v2\/pages\/342","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fatware.jp\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.fatware.jp\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.fatware.jp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fatware.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=342"}],"version-history":[{"count":2,"href":"https:\/\/www.fatware.jp\/index.php?rest_route=\/wp\/v2\/pages\/342\/revisions"}],"predecessor-version":[{"id":347,"href":"https:\/\/www.fatware.jp\/index.php?rest_route=\/wp\/v2\/pages\/342\/revisions\/347"}],"up":[{"embeddable":true,"href":"https:\/\/www.fatware.jp\/index.php?rest_route=\/wp\/v2\/pages\/363"}],"wp:attachment":[{"href":"https:\/\/www.fatware.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=342"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}