{"id":1756,"date":"2020-02-07T01:24:25","date_gmt":"2020-02-06T16:24:25","guid":{"rendered":"https:\/\/took.jp\/?p=1756"},"modified":"2020-06-22T21:07:34","modified_gmt":"2020-06-22T12:07:34","slug":"mysql-column-open","status":"publish","type":"post","link":"https:\/\/took.jp\/tech-blog\/mysql-column-open\/","title":{"rendered":"MySQL\u3067\u30ab\u30e9\u30e0\u306b\u4f7f\u7528\u3059\u308b\u5909\u6570\u540d\u3092\u5c55\u958b\u3057\u305f\u3044\u5834\u5408\u306e\u8a18\u8ff0\u65b9\u6cd5"},"content":{"rendered":"

\u30bf\u30a4\u30c8\u30eb\u3060\u3068\u5c11\u3057\u308f\u304b\u308a\u3065\u3089\u3044\u3067\u3059\u304c\u3001<\/p>\n

\u4f8b\u3048\u3070\u3001\u300csample1\u300d\u300csample2\u300d\u300csample3\u300d\u3068\u3044\u3046\u3088\u3046\u306a\u9023\u756a\u306e\u30ab\u30e9\u30e0\u3067\u3042\u3063\u305f\u5834\u5408\u306a\u3069\u306f\u3001\u30ab\u30e9\u30e0\u540d\u90e8\u5206\u3092\u5909\u6570\u306b\u3057\u3001\u300csample\u300d\u3068\u3044\u3046\u6587\u5b57\u3068\u30a4\u30f3\u30af\u30ea\u30e1\u30f3\u30c8\u3059\u308b\u5024\u3092\u7d50\u5408\u3057\u305f\u3082\u306e\u3092\u4ee3\u5165\u3059\u308b\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n

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\u305f\u3060\u3001\u305d\u306e\u307e\u307e\u51e6\u7406\u3092\u66f8\u3044\u305f\u5834\u5408\u306f\u3001\u5909\u6570\u304c\u5c55\u958b\u3055\u308c\u305a\u3001\u6b63\u3057\u3044\u5024\u304c\u53d6\u5f97\u3067\u304d\u307e\u305b\u3093\u3002<\/p>\n

\u4f8b\u3048\u3070\u3053\u3046\u3067\u3059\u3002<\/p>\n

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mysql> set @test =concat('sample','1');\r\nQuery OK, 0 rows affected (0.00 sec)\r\n\r\nmysql> select @test from tablename;\r\n+---------+\r\n| @test   |\r\n+---------+\r\n| sample1 |\r\n| sample1 |\r\n| sample1 |\r\n+---------+\r\n\r\n3 rows in set (0.00 sec)<\/code><\/pre>\n
 <\/p>\n
\u5024\u306e\u53d6\u5f97\u306b\u5931\u6557\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
MySQL\u306f\u3001\u5b58\u5728\u3057\u306a\u3044\u30ab\u30e9\u30e0\u540d\u3067\u3042\u3063\u3066\u3082\u30c6\u30fc\u30d6\u30eb\u304c\u5b58\u5728\u3059\u308c\u3070\u30a8\u30e9\u30fc\u306f\u5410\u304b\u305a\u3001\u305d\u306e\u30ab\u30e9\u30e0\u540d\uff08\u5b58\u5728\u3057\u306a\u3044\u30ab\u30e9\u30e0\u540d\uff09\u3067\u30de\u30b9\u30ad\u30f3\u30b0\u3057\u305f\u72b6\u614b\u3067\u5024\u3092\u8fd4\u3057\u307e\u3059\u3002<\/p>\n
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\u89e3\u6c7a\u6cd5<\/h2>\n
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 <\/p>\n
mysql> set @test =concat('sample','1');\r\nQuery OK, 0 rows affected (0.00 sec)\r\nmysql> set @query = concat('select ',@test ,' from tablename');\r\nQuery OK, 0 rows affected (0.00 sec)\r\nmysql> prepare stmt from @query;\r\nQuery OK, 0 rows affected (0.00 sec)\r\nStatement prepared\r\n\r\nmysql> execute stmt;\r\n\r\n+---------+\r\n| sample1 |\r\n+---------+\r\n| test001 |\r\n| test002 |\r\n| test003 |\r\n+---------+<\/code><\/pre>\n
 <\/p>\n
\u5b9a\u7fa9\u3057\u305f\u5909\u6570\u3092\u4f7f\u7528\u3057\u3001\u30af\u30a8\u30ea\u3092\u5909\u6570\u3068\u3057\u3066\u5b9a\u7fa9\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u305d\u306e\u5f8c\u306e\u52d5\u4f5c\u306f\u3001\u5b9a\u578b\u6587\u3068\u3057\u3066\u8003\u3048\u3066\u3088\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n
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\u95a2\u9023\u306e\u66f8\u7c4d<\/h2>\n
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\n\t\t\t\t\t\t\t\t\t\u57fa\u790e\u304b\u3089\u306eMySQL \u7b2c3\u7248 [ \u897f\u6ca2 \u5922\u8def ]<\/a>\t\t\t\t\t\t\t<\/div>\n\t\t\t
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created by Rinker<\/a><\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\u00a53,278<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t(2026\/04\/11 12:40:56\u6642\u70b9 \u697d\u5929\u5e02\u5834\u8abf\u3079-<\/span>\u8a73\u7d30)<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t