ChinaITLab\u6536\u96c6\u6574\u7406<\/p>\n
\u4e00\u3001 \u7b80\u5355\u67e5\u8be2<\/p>\n
\u7b80\u5355\u7684Transact-SQL\u67e5\u8be2\u53ea\u5305\u62ec\u9009\u62e9\u5217\u8868\u3001FROM\u5b50\u53e5\u548cWHERE\u5b50\u53e5\u3002\u5b83\u4eec\u5206\u522b\u8bf4\u660e\u6240\u67e5\u8be2\u5217\u3001\u67e5\u8be2\u7684\u8868\u6216\u89c6\u56fe\u3001\u4ee5\u53ca\u641c\u7d22\u6761\u4ef6\u7b49\u3002<\/p>\n
\u4f8b\u5982\uff0c\u4e0b\u9762\u7684\u8bed\u53e5\u67e5\u8be2testtable\u8868\u4e2d\u59d3\u540d\u4e3a\u201c\u5f20\u4e09\u201d\u7684nickname\u5b57\u6bb5\u548cemail\u5b57\u6bb5\u3002<\/p>\n
SELECT nickname,email
\nFROM testtable
\nWHERE name=’\u5f20\u4e09’<\/p>\n
(\u4e00) \u9009\u62e9\u5217\u8868<\/p>\n
\u9009\u62e9\u5217\u8868(select_list)\u6307\u51fa\u6240\u67e5\u8be2\u5217\uff0c\u5b83\u53ef\u4ee5\u662f\u4e00\u7ec4\u5217\u540d\u5217\u8868\u3001\u661f\u53f7\u3001\u8868\u8fbe\u5f0f\u3001\u53d8\u91cf(\u5305\u62ec\u5c40\u90e8\u53d8\u91cf\u548c\u5168\u5c40\u53d8\u91cf)\u7b49\u6784\u6210\u3002<\/p>\n
1\u3001\u9009\u62e9\u6240\u6709\u5217<\/p>\n
\u4f8b\u5982\uff0c\u4e0b\u9762\u8bed\u53e5\u663e\u793atesttable\u8868\u4e2d\u6240\u6709\u5217\u7684\u6570\u636e\uff1a<\/p>\n
SELECT *
\nFROM testtable<\/p>\n
2\u3001\u9009\u62e9\u90e8\u5206\u5217\u5e76\u6307\u5b9a\u5b83\u4eec\u7684\u663e\u793a\u6b21\u5e8f<\/p>\n
\u67e5\u8be2\u7ed3\u679c\u96c6\u5408\u4e2d\u6570\u636e\u7684\u6392\u5217\u987a\u5e8f\u4e0e\u9009\u62e9\u5217\u8868\u4e2d\u6240\u6307\u5b9a\u7684\u5217\u540d\u6392\u5217\u987a\u5e8f\u76f8\u540c\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT nickname,email
\nFROM testtable<\/p>\n
3\u3001\u66f4\u6539\u5217\u6807\u9898<\/p>\n
\u5728\u9009\u62e9\u5217\u8868\u4e2d\uff0c\u53ef\u91cd\u65b0\u6307\u5b9a\u5217\u6807\u9898\u3002\u5b9a\u4e49\u683c\u5f0f\u4e3a\uff1a<\/p>\n
\u5217\u6807\u9898=\u5217\u540d
\n\u5217\u540d \u5217\u6807\u9898<\/p>\n
\u5982\u679c\u6307\u5b9a\u7684\u5217\u6807\u9898\u4e0d\u662f\u6807\u51c6\u7684\u6807\u8bc6\u7b26\u683c\u5f0f\u65f6\uff0c\u5e94\u4f7f\u7528\u5f15\u53f7\u5b9a\u754c\u7b26\uff0c\u4f8b\u5982\uff0c\u4e0b\u5217\u8bed\u53e5\u4f7f\u7528\u6c49\u5b57\u663e\u793a\u5217\u6807\u9898\uff1a<\/p>\n
SELECT \u6635\u79f0=nickname,\u7535\u5b50\u90ae\u4ef6=email
\nFROM testtable<\/p>\n
4\u3001\u5220\u9664\u91cd\u590d\u884c<\/p>\n
SELECT\u8bed\u53e5\u4e2d\u4f7f\u7528ALL\u6216DISTINCT\u9009\u9879\u6765\u663e\u793a\u8868\u4e2d\u7b26\u5408\u6761\u4ef6\u7684\u6240\u6709\u884c\u6216\u5220\u9664\u5176\u4e2d\u91cd\u590d\u7684\u6570\u636e\u884c\uff0c\u9ed8\u8ba4\u4e3aALL\u3002\u4f7f\u7528DISTINCT\u9009\u9879\u65f6\uff0c\u5bf9\u4e8e\u6240\u6709\u91cd\u590d\u7684\u6570\u636e\u884c\u5728SELECT\u8fd4\u56de\u7684\u7ed3\u679c\u96c6\u5408\u4e2d\u53ea\u4fdd\u7559\u4e00\u884c\u3002<\/p>\n
5\u3001\u9650\u5236\u8fd4\u56de\u7684\u884c\u6570<\/p>\n
\u4f7f\u7528TOP n [PERCENT]\u9009\u9879\u9650\u5236\u8fd4\u56de\u7684\u6570\u636e\u884c\u6570\uff0cTOP n\u8bf4\u660e\u8fd4\u56den\u884c\uff0c\u800cTOP n PERCENT\u65f6\uff0c\u8bf4\u660en\u662f\u8868\u793a\u4e00\u767e\u5206\u6570\uff0c\u6307\u5b9a\u8fd4\u56de\u7684\u884c\u6570\u7b49\u4e8e\u603b\u884c\u6570\u7684\u767e\u5206\u4e4b\u51e0\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT TOP 2 *FROM testtable SELECT TOP 20 PERCENT * FROM testtable<\/p>\n
(\u4e8c) FROM\u5b50\u53e5<\/p>\n
FROM\u5b50\u53e5\u6307\u5b9aSELECT\u8bed\u53e5\u67e5\u8be2\u53ca\u4e0e\u67e5\u8be2\u76f8\u5173\u7684\u8868\u6216\u89c6\u56fe\u3002\u5728FROM\u5b50\u53e5\u4e2d\u6700\u591a\u53ef\u6307\u5b9a256\u4e2a\u8868\u6216\u89c6\u56fe\uff0c\u5b83\u4eec\u4e4b\u95f4\u7528\u9017\u53f7\u5206\u9694\u3002<\/p>\n
\u5728FROM\u5b50\u53e5\u540c\u65f6\u6307\u5b9a\u591a\u4e2a\u8868\u6216\u89c6\u56fe\u65f6\uff0c\u5982\u679c\u9009\u62e9\u5217\u8868\u4e2d\u5b58\u5728\u540c\u540d\u5217\uff0c\u8fd9\u65f6\u5e94\u4f7f\u7528\u5bf9\u8c61\u540d\u9650\u5b9a\u8fd9\u4e9b\u5217\u6240\u5c5e\u7684\u8868\u6216\u89c6\u56fe\u3002\u4f8b\u5982\u5728usertable\u548ccitytable\u8868\u4e2d\u540c\u65f6\u5b58\u5728cityid\u5217\uff0c\u5728\u67e5\u8be2\u4e24\u4e2a\u8868\u4e2d\u7684cityid\u65f6\u5e94\u4f7f\u7528\u4e0b\u9762\u8bed\u53e5\u683c\u5f0f\u52a0\u4ee5\u9650\u5b9a\uff1a<\/p>\n
SELECT username,citytable.cityid
\nFROM usertable,citytable
\nWHERE usertable.cityid=citytable.cityid<\/p>\n
\u5728FROM\u5b50\u53e5\u4e2d\u53ef\u7528\u4ee5\u4e0b\u4e24\u79cd\u683c\u5f0f\u4e3a\u8868\u6216\u89c6\u56fe\u6307\u5b9a\u522b\u540d\uff1a<\/p>\n
\u8868\u540d as \u522b\u540d
\n\u8868\u540d \u522b\u540d<\/p>\n
\u4f8b\u5982\u4e0a\u9762\u8bed\u53e5\u53ef\u7528\u8868\u7684\u522b\u540d\u683c\u5f0f\u8868\u793a\u4e3a\uff1a<\/p>\n
SELECT username,b.cityid
\nFROM usertable a,citytable b
\nWHERE a.cityid=b.cityid<\/p>\n
SELECT\u4e0d\u4ec5\u80fd\u4ece\u8868\u6216\u89c6\u56fe\u4e2d\u68c0\u7d22\u6570\u636e\uff0c\u5b83\u8fd8\u80fd\u591f\u4ece\u5176\u5b83\u67e5\u8be2\u8bed\u53e5\u6240\u8fd4\u56de\u7684\u7ed3\u679c\u96c6\u5408\u4e2d\u67e5\u8be2\u6570\u636e\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT a.au_fname+a.au_lname
\nFROM authors a,titleauthor ta
\n(SELECT title_id,title
\nFROM titles
\nWHERE ytd_sales>10000
\n) AS t
\nWHERE a.au_id=ta.au_id
\nAND ta.title_id=t.title_id<\/p>\n
\u6b64\u4f8b\u4e2d\uff0c\u5c06SELECT\u8fd4\u56de\u7684\u7ed3\u679c\u96c6\u5408\u7ed9\u4e88\u4e00\u522b\u540dt\uff0c\u7136\u540e\u518d\u4ece\u4e2d\u68c0\u7d22\u6570\u636e\u3002<\/p>\n
(\u4e09) \u4f7f\u7528WHERE\u5b50\u53e5\u8bbe\u7f6e\u67e5\u8be2\u6761\u4ef6<\/p>\n
WHERE\u5b50\u53e5\u8bbe\u7f6e\u67e5\u8be2\u6761\u4ef6\uff0c\u8fc7\u6ee4\u6389\u4e0d\u9700\u8981\u7684\u6570\u636e\u884c\u3002\u4f8b\u5982\u4e0b\u9762\u8bed\u53e5\u67e5\u8be2\u5e74\u9f84\u5927\u4e8e20\u7684\u6570\u636e\uff1a<\/p>\n
SELECT *
\nFROM usertable
\nWHERE age>20<\/p>\n
WHERE\u5b50\u53e5\u53ef\u5305\u62ec\u5404\u79cd\u6761\u4ef6\u8fd0\u7b97\u7b26\uff1a<\/p>\n
\u6bd4\u8f83\u8fd0\u7b97\u7b26(\u5927\u5c0f\u6bd4\u8f83)\uff1a>\u3001>=\u3001=\u3001<\u3001<=\u3001<>\u3001!>\u3001!<
\n\u8303\u56f4\u8fd0\u7b97\u7b26(\u8868\u8fbe\u5f0f\u503c\u662f\u5426\u5728\u6307\u5b9a\u7684\u8303\u56f4)\uff1aBETWEEN\u2026AND\u2026
\nNOT BETWEEN\u2026AND\u2026
\n\u5217\u8868\u8fd0\u7b97\u7b26(\u5224\u65ad\u8868\u8fbe\u5f0f\u662f\u5426\u4e3a\u5217\u8868\u4e2d\u7684\u6307\u5b9a\u9879)\uff1aIN (\u98791,\u98792\u2026\u2026)
\nNOT IN (\u98791,\u98792\u2026\u2026)
\n\u6a21\u5f0f\u5339\u914d\u7b26(\u5224\u65ad\u503c\u662f\u5426\u4e0e\u6307\u5b9a\u7684\u5b57\u7b26\u901a\u914d\u683c\u5f0f\u76f8\u7b26):LIKE\u3001NOT LIKE
\n\u7a7a\u503c\u5224\u65ad\u7b26(\u5224\u65ad\u8868\u8fbe\u5f0f\u662f\u5426\u4e3a\u7a7a)\uff1aIS NULL\u3001NOT IS NULL
\n\u903b\u8f91\u8fd0\u7b97\u7b26(\u7528\u4e8e\u591a\u6761\u4ef6\u7684\u903b\u8f91\u8fde\u63a5)\uff1aNOT\u3001AND\u3001OR<\/p>\n
1\u3001\u8303\u56f4\u8fd0\u7b97\u7b26\u4f8b\uff1aage BETWEEN 10 AND 30\u76f8\u5f53\u4e8eage>=10 AND age<=30<\/p>\n
2\u3001\u5217\u8868\u8fd0\u7b97\u7b26\u4f8b\uff1acountry IN (‘Germany’,’China’)<\/p>\n
3\u3001\u6a21\u5f0f\u5339\u914d\u7b26\u4f8b\uff1a\u5e38\u7528\u4e8e\u6a21\u7cca\u67e5\u627e\uff0c\u5b83\u5224\u65ad\u5217\u503c\u662f\u5426\u4e0e\u6307\u5b9a\u7684\u5b57\u7b26\u4e32\u683c\u5f0f\u76f8\u5339\u914d\u3002\u53ef\u7528\u4e8echar\u3001varchar\u3001text\u3001ntext\u3001datetime\u548csmalldatetime\u7b49\u7c7b\u578b\u67e5\u8be2\u3002<\/p>\n
\u53ef\u4f7f\u7528\u4ee5\u4e0b\u901a\u914d\u5b57\u7b26\uff1a<\/p>\n
\u767e\u5206\u53f7%\uff1a\u53ef\u5339\u914d\u4efb\u610f\u7c7b\u578b\u548c\u957f\u5ea6\u7684\u5b57\u7b26\uff0c\u5982\u679c\u662f\u4e2d\u6587\uff0c\u8bf7\u4f7f\u7528\u4e24\u4e2a\u767e\u5206\u53f7\u5373%%\u3002<\/p>\n
\u4e0b\u5212\u7ebf_\uff1a\u5339\u914d\u5355\u4e2a\u4efb\u610f\u5b57\u7b26\uff0c\u5b83\u5e38\u7528\u6765\u9650\u5236\u8868\u8fbe\u5f0f\u7684\u5b57\u7b26\u957f\u5ea6\u3002<\/p>\n
\u65b9\u62ec\u53f7[]\uff1a\u6307\u5b9a\u4e00\u4e2a\u5b57\u7b26\u3001\u5b57\u7b26\u4e32\u6216\u8303\u56f4\uff0c\u8981\u6c42\u6240\u5339\u914d\u5bf9\u8c61\u4e3a\u5b83\u4eec\u4e2d\u7684\u4efb\u4e00\u4e2a\u3002[^]\uff1a\u5176\u53d6\u503c\u4e5f[] \u76f8\u540c\uff0c\u4f46\u5b83\u8981\u6c42\u6240\u5339\u914d\u5bf9\u8c61\u4e3a\u6307\u5b9a\u5b57\u7b26\u4ee5\u5916\u7684\u4efb\u4e00\u4e2a\u5b57\u7b26\u3002<\/p>\n
\u4f8b\u5982\uff1a<\/p>\n
\u9650\u5236\u4ee5Publishing\u7ed3\u5c3e\uff0c\u4f7f\u7528LIKE ‘%Publishing’<\/p>\n
\u9650\u5236\u4ee5A\u5f00\u5934\uff1aLIKE ‘[A]%’<\/p>\n
\u9650\u5236\u4ee5A\u5f00\u5934\u5916\uff1aLIKE ‘[^A]%’<\/p>\n
4\u3001\u7a7a\u503c\u5224\u65ad\u7b26\u4f8bWHERE age IS NULL<\/p>\n
5\u3001\u903b\u8f91\u8fd0\u7b97\u7b26\uff1a\u4f18\u5148\u7ea7\u4e3aNOT\u3001AND\u3001OR<\/p>\n
(\u56db)\u67e5\u8be2\u7ed3\u679c\u6392\u5e8f<\/p>\n
\u4f7f\u7528ORDER BY\u5b50\u53e5\u5bf9\u67e5\u8be2\u8fd4\u56de\u7684\u7ed3\u679c\u6309\u4e00\u5217\u6216\u591a\u5217\u6392\u5e8f\u3002ORDER BY\u5b50\u53e5\u7684\u8bed\u6cd5\u683c\u5f0f\u4e3a\uff1a<\/p>\n
ORDER BY {column_name [ASC|DESC]} [,\u2026n]<\/p>\n
\u5176\u4e2dASC\u8868\u793a\u5347\u5e8f\uff0c\u4e3a\u9ed8\u8ba4\u503c\uff0cDESC\u4e3a\u964d\u5e8f\u3002ORDER BY\u4e0d\u80fd\u6309ntext\u3001text\u548cimage\u6570\u636e\u7c7b\u578b\u8fdb\u884c\u6392\u5e8f\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT *
\nFROM usertable
\nORDER BY age desc,userid ASC<\/p>\n
\u53e6\u5916\uff0c\u53ef\u4ee5\u6839\u636e\u8868\u8fbe\u5f0f\u8fdb\u884c\u6392\u5e8f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
ChinaITLab\u6536\u96c6\u6574\u7406 \u4e00\u3001 \u7b80\u5355\u67e5\u8be2 \u7b80\u5355\u7684Transact-SQL\u67e5\u8be2\u53ea\u5305\u62ec\u9009\u62e9\u5217\u8868\u3001FROM\u5b50\u53e5\u548c […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[42],"tags":[43,44],"_links":{"self":[{"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/posts\/79"}],"collection":[{"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/comments?post=79"}],"version-history":[{"count":1,"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/posts\/79\/revisions"}],"predecessor-version":[{"id":80,"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/posts\/79\/revisions\/80"}],"wp:attachment":[{"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/media?parent=79"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/categories?post=79"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecjtu.com\/keith\/wp-json\/wp\/v2\/tags?post=79"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}