<\/b> <\/p>\n\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u8f6c\u6362\u548c\u8f6c\u79fb\uff1f<\/h1>\n
\u5bf9\u4e8e\u4e00\u4e2a\u6570\u636e\u5e93\u5f00\u53d1\u8005\u6765\u8bf4\uff0c\u7262\u56fa\u624e\u5b9e\u7684\u57fa\u7840\u662f\u5341\u5206\u91cd\u8981\u7684\uff0c\u4e3b\u673a\u5b9d\u8d1d\u5c31\u6765\u5e26\u5927\u5bb6\u4e00\u70b9\u70b9\u7684\u638c\u63e1\u57fa\u7840\u77e5\u8bc6\u70b9\u3002\u4eca\u5929\u672c\u7bc7\u6587\u7ae0\u5e26\u5927\u5bb6\u4e86\u89e3\u300a\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u8f6c\u6362\u548c\u8f6c\u79fb\uff1f\u300b\uff0c\u4e3b\u8981\u4ecb\u7ecd\u4e86\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u5feb\u70b9\u6536\u85cf\u8d77\u6765\u5427\uff0c\u5426\u5219\u9700\u8981\u65f6\u5c31\u627e\u4e0d\u5230\u4e86\uff01<\/p>\n
\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u8f6c\u6362\u548c\u8f6c\u79fb\u662f\u4e00\u4e2a\u5e38\u89c1\u7684\u4efb\u52a1\u3002\u8fd9\u79cd\u4efb\u52a1\u6709\u5f88\u591a\u79cd\u4e0d\u540c\u7684\u65b9\u6cd5\uff0c\u5176\u4e2d\u6700\u5e38\u89c1\u7684\u65b9\u6cd5\u662f\u4f7f\u7528SQL\u8bed\u53e5\u3002\u672c\u6587\u5c06\u4ecb\u7ecd\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u8f6c\u6362\u548c\u8f6c\u79fb\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n
\u4e00\u3001\u6570\u636e\u8f6c\u6362<\/p>\n
\u6570\u636e\u8f6c\u6362\u662f\u5c06\u4e00\u4e2a\u6216\u591a\u4e2a\u6570\u636e\u7c7b\u578b\u8f6c\u6362\u4e3a\u53e6\u4e00\u4e2a\u6570\u636e\u7c7b\u578b\u7684\u8fc7\u7a0b\u3002\u5728MySQL\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528CAST\u548cCONVERT\u51fd\u6570\u6765\u5b9e\u73b0\u6570\u636e\u7c7b\u578b\u8f6c\u6362\u3002<\/p>\n
CAST\u51fd\u6570\u7528\u4e8e\u5c06\u4e00\u4e2a\u8868\u8fbe\u5f0f\u8f6c\u6362\u4e3a\u6307\u5b9a\u7684\u6570\u636e\u7c7b\u578b\u3002\u5176\u57fa\u672c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n
CAST ( expression AS datatype )<\/p>\n
\u5176\u4e2d\uff0cexpression\u662f\u8981\u8f6c\u6362\u7684\u8868\u8fbe\u5f0f\uff0cdatatype\u662f\u8981\u8f6c\u6362\u6210\u7684\u76ee\u6807\u6570\u636e\u7c7b\u578b\u3002<\/p>\n
\u793a\u4f8b1\uff1a\u5c06\u5b57\u7b26\u4e32”123″\u8f6c\u6362\u4e3a\u6574\u578b\u3002<\/p>\n
SELECT CAST(‘123’ AS SIGNED);<\/p>\n
\u793a\u4f8b2\uff1a\u5c06\u6d6e\u70b9\u65701.23\u8f6c\u6362\u4e3a\u6574\u578b\u3002<\/p>\n
SELECT CAST(1.23 AS SIGNED);<\/p>\n
CONVERT\u51fd\u6570\u4e5f\u53ef\u4ee5\u5b9e\u73b0\u6570\u636e\u7c7b\u578b\u8f6c\u6362\u3002\u5176\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n
CONVERT ( expression , datatype )<\/p>\n
\u5176\u4e2d\uff0cexpression\u662f\u8981\u8f6c\u6362\u7684\u8868\u8fbe\u5f0f\uff0cdatatype\u662f\u8981\u8f6c\u6362\u6210\u7684\u76ee\u6807\u6570\u636e\u7c7b\u578b\u3002\u4e0eCAST\u51fd\u6570\u4e0d\u540c\u7684\u662f\uff0cCONVERT\u51fd\u6570\u8fd8\u53ef\u4ee5\u6307\u5b9a\u5b57\u7b26\u96c6\u3002<\/p>\n
\u793a\u4f8b1\uff1a\u5c06\u5b57\u7b26\u4e32”123″\u8f6c\u6362\u4e3a\u6574\u578b\u3002<\/p>\n
SELECT CONVERT(‘123’, SIGNED);<\/p>\n
\u793a\u4f8b2\uff1a\u5c06ISO-8859-1\u7f16\u7801\u7684\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3aUTF-8\u7f16\u7801\u7684\u5b57\u7b26\u4e32\u3002<\/p>\n
SELECT CONVERT(‘Hello, world!’ USING utf8);<\/p>\n
\u4e8c\u3001\u6570\u636e\u8f6c\u79fb<\/p>\n
\u6570\u636e\u8f6c\u79fb\u662f\u5c06\u4e00\u4efd\u6570\u636e\u4ece\u4e00\u4e2a\u8868\u6216\u6570\u636e\u5e93\u590d\u5236\u5230\u53e6\u4e00\u4e2a\u8868\u6216\u6570\u636e\u5e93\u7684\u8fc7\u7a0b\u3002\u5728MySQL\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528INSERT INTO SELECT\u8bed\u53e5\u6765\u5b9e\u73b0\u6570\u636e\u8f6c\u79fb\u3002<\/p>\n
INSERT INTO SELECT\u8bed\u53e5\u7528\u4e8e\u5c06\u4e00\u4e2a\u8868\u4e2d\u7684\u6570\u636e\u590d\u5236\u5230\u53e6\u4e00\u4e2a\u8868\u4e2d\u3002\u5176\u57fa\u672c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n
INSERT INTO table2 ( column1, column2, … )
SELECT column1, column2, …
FROM table1
WHERE condition;<\/p>\n
\u5176\u4e2d\uff0ctable1\u662f\u8981\u590d\u5236\u7684\u6e90\u8868\uff0ctable2\u662f\u8981\u590d\u5236\u5230\u7684\u76ee\u6807\u8868\uff0ccolumn1, column2, …\u662f\u8981\u590d\u5236\u7684\u5b57\u6bb5\u3002<\/p>\n
\u793a\u4f8b\uff1a\u5c06employees\u8868\u4e2d\u7684\u6240\u6709\u6570\u636e\u590d\u5236\u5230employees_backup\u8868\u4e2d\u3002<\/p>\n
INSERT INTO employees_backup
SELECT *
FROM employees;<\/p>\n
\u9664\u4e86\u5c06\u6570\u636e\u4ece\u4e00\u4e2a\u8868\u590d\u5236\u5230\u53e6\u4e00\u4e2a\u8868\uff0cINSERT INTO SELECT\u8bed\u53e5\u8fd8\u53ef\u4ee5\u5c06\u6570\u636e\u4ece\u4e00\u4e2a\u8868\u590d\u5236\u5230\u540c\u4e00\u8868\u7684\u53e6\u4e00\u4e2a\u4f4d\u7f6e\u3002\u5176\u57fa\u672c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n
INSERT INTO table ( column1, column2, … )
SELECT column1, column2, …
FROM table
WHERE condition;<\/p>\n
\u793a\u4f8b\uff1a\u5c06employees\u8868\u4e2d\u7684\u90e8\u5206\u6570\u636e\u590d\u5236\u5230\u540c\u4e00\u8868\u7684\u53e6\u4e00\u4e2a\u4f4d\u7f6e\u3002<\/p>\n
INSERT INTO employees (employee_id, first_name, last_name)
SELECT employee_id, first_name, last_name
FROM employees
WHERE department_id = 1;<\/p>\n
\u8fd9\u5c06\u4f1a\u590d\u5236employees\u8868\u4e2d\u90e8\u95e8\u7f16\u53f7\u4e3a1\u7684\u5458\u5de5\u7684ID\u3001\u540d\u5b57\u548c\u59d3\u6c0f\u5230employees\u8868\u4e2d\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u8f6c\u6362\u548c\u8f6c\u79fb\u7684\u4ecb\u7ecd\u3002\u901a\u8fc7CAST\u548cCONVERT\u51fd\u6570\uff0c\u53ef\u4ee5\u5b9e\u73b0\u4e0d\u540c\u6570\u636e\u7c7b\u578b\u4e4b\u95f4\u7684\u8f6c\u6362\uff1b\u901a\u8fc7INSERT INTO SELECT\u8bed\u53e5\uff0c\u53ef\u4ee5\u5c06\u6570\u636e\u4ece\u4e00\u4e2a\u8868\u6216\u4f4d\u7f6e\u590d\u5236\u5230\u53e6\u4e00\u4e2a\u8868\u6216\u4f4d\u7f6e\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u300a\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d\u8fdb\u884c\u6570\u636e\u8f6c\u6362\u548c\u8f6c\u79fb\uff1f\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8emysql,\u6570\u636e\u8f6c\u6362,\u6570\u636e\u8f6c\u6362\uff1aSQL\u8bed\u53e5,\u6570\u636e\u8f6c\u79fb\uff1aSQL\u8bed\u53e5\u7684\u8d44\u6599\u8bf7\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff01<\/p>\n
\u5982\u4f55\u4f7f\u7528SQL\u8bed\u53e5\u5728MySQL\u4e2d...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-199618","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199618","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=199618"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199618\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=199618"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=199618"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=199618"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}