{"id":737,"date":"2015-06-01T14:56:11","date_gmt":"2015-06-01T06:56:11","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=737"},"modified":"2015-06-01T14:56:11","modified_gmt":"2015-06-01T06:56:11","slug":"%e7%bb%8f%e5%85%b8sql%e8%af%ad%e5%8f%a5%e5%a4%a7%e5%85%a8","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=737","title":{"rendered":"\u7ecf\u5178SQL\u8bed\u53e5\u5927\u5168"},"content":{"rendered":"

\u7ecf\u5178SQL\u8bed\u53e5<\/a><\/p>\n

<\/p>\n

<\/a>\u4e00\u3001\u57fa\u7840<\/strong><\/p>\n

<\/a>1<\/strong>\u3001\u8bf4\u660e\uff1a\u521b\u5efa\u6570\u636e\u5e93<\/strong>
\nCREATE DATABASE database-name<\/strong>
\n2<\/strong>\u3001\u8bf4\u660e\uff1a\u5220\u9664\u6570\u636e\u5e93
\ndrop database dbname<\/strong>
\n3\u3001\u8bf4\u660e\uff1a\u5907\u4efdsql server
\n— \u521b\u5efa \u5907\u4efd\u6570\u636e\u7684 device
\nUSE master
\nEXEC sp_addumpdevice ‘disk’, ‘testBack’, ‘c:\\mssql7backup\\MyNwind_1.dat’
\n— \u5f00\u59cb \u5907\u4efd
\nBACKUP DATABASE pubs TO testBack<\/strong>
\n4\u3001\u8bf4\u660e\uff1a\u521b\u5efa\u65b0\u8868
\ncreate table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)<\/strong><\/p>\n

<\/a>\u6839\u636e\u5df2\u6709\u7684\u8868\u521b\u5efa\u65b0\u8868\uff1a <\/strong>
\nA\uff1acreate table tab_new like tab_old (\u4f7f\u7528\u65e7\u8868\u521b\u5efa\u65b0\u8868)<\/strong>
\nB<\/strong>\uff1acreate table tab_new as select col1,col2\u2026 from tab_old definition only<\/strong>
\n5\u3001\u8bf4\u660e\uff1a\u5220\u9664\u65b0\u8868
\ndrop table tabname<\/strong>
\n6\u3001\u8bf4\u660e\uff1a\u589e\u52a0\u4e00\u4e2a\u5217
\nAlter table tabname add column col type<\/strong>
\n\u6ce8<\/strong>\uff1a\u5217\u589e\u52a0\u540e\u5c06\u4e0d\u80fd\u5220\u9664\u3002DB2\u4e2d\u5217\u52a0\u4e0a\u540e\u6570\u636e\u7c7b\u578b\u4e5f\u4e0d\u80fd\u6539\u53d8\uff0c\u552f\u4e00\u80fd\u6539\u53d8\u7684\u662f\u589e\u52a0varchar\u7c7b\u578b\u7684\u957f\u5ea6\u3002
\n<\/span>7\u3001\u8bf4\u660e\uff1a\u6dfb\u52a0\u4e3b\u952e<\/strong>\uff1a Alter table tabname add primary key(col)
\n<\/strong>\u8bf4\u660e\uff1a\u5220\u9664\u4e3b\u952e\uff1a Alter table tabname drop primary key(col) <\/strong>
\n8\u3001\u8bf4\u660e\uff1a\u521b\u5efa\u7d22\u5f15<\/strong>\uff1acreate [unique] index idxname on tabname(col\u2026.)
\n<\/strong>\u5220\u9664\u7d22\u5f15\uff1adrop index idxname<\/strong>
\n\u6ce8\uff1a\u7d22\u5f15\u662f\u4e0d\u53ef\u66f4\u6539\u7684\uff0c\u60f3\u66f4\u6539\u5fc5\u987b\u5220\u9664\u91cd\u65b0\u5efa\u3002
\n9<\/strong>\u3001\u8bf4\u660e\uff1a\u521b\u5efa\u89c6\u56fe<\/strong>\uff1acreate view viewname as select statement
\n\u5220\u9664\u89c6\u56fe<\/strong>\uff1adrop view viewname
\n10<\/strong>\u3001\u8bf4\u660e\uff1a\u51e0\u4e2a\u7b80\u5355\u7684\u57fa\u672c\u7684sql\u8bed\u53e5
\n\u9009\u62e9\uff1a<\/strong>select * from table1 where \u8303\u56f4
\n\u63d2\u5165\uff1a<\/strong>insert into table1(field1,field2) values(value1,value2)
\n\u5220\u9664\uff1a<\/strong>delete from table1 where \u8303\u56f4
\n\u66f4\u65b0<\/strong>\uff1aupdate table1 set field1=value1 where \u8303\u56f4
\n\u67e5\u627e<\/strong>\uff1aselect * from table1 where field1 like \u2019%value1%\u2019 —like\u7684\u8bed\u6cd5\u5f88\u7cbe\u5999\uff0c\u67e5\u8d44\u6599!
\n\u6392\u5e8f<\/strong>\uff1aselect * from table1 order by field1,field2 [desc]
\n\u603b\u6570<\/strong>\uff1aselect count as totalcount from table1
\n\u6c42\u548c<\/strong>\uff1aselect sum(field1) as sumvalue from table1
\n\u5e73\u5747<\/strong>\uff1aselect avg(field1) as avgvalue from table1
\n\u6700\u5927<\/strong>\uff1aselect max(field1) as maxvalue from table1
\n\u6700\u5c0f<\/strong>\uff1aselect min(field1) as minvalue from table1
\n11\u3001\u8bf4\u660e\uff1a\u51e0\u4e2a\u9ad8\u7ea7\u67e5\u8be2\u8fd0\u7b97\u8bcd
\nA\uff1a UNION \u8fd0\u7b97\u7b26<\/strong>
\nUNION \u8fd0\u7b97\u7b26\u901a\u8fc7\u7ec4\u5408\u5176\u4ed6\u4e24\u4e2a\u7ed3\u679c\u8868\uff08\u4f8b\u5982 TABLE1 \u548c TABLE2\uff09\u5e76\u6d88\u53bb\u8868\u4e2d\u4efb\u4f55\u91cd\u590d\u884c\u800c\u6d3e\u751f\u51fa\u4e00\u4e2a\u7ed3\u679c\u8868\u3002\u5f53 ALL \u968f UNION \u4e00\u8d77\u4f7f\u7528\u65f6\uff08\u5373 UNION ALL\uff09\uff0c\u4e0d\u6d88\u9664\u91cd\u590d\u884c\u3002\u4e24\u79cd\u60c5\u51b5\u4e0b\uff0c\u6d3e\u751f\u8868\u7684\u6bcf\u4e00\u884c\u4e0d\u662f\u6765\u81ea TABLE1 \u5c31\u662f\u6765\u81ea TABLE2\u3002
\nB\uff1a EXCEPT \u8fd0\u7b97\u7b26
\nEXCEPT<\/strong> \u8fd0\u7b97\u7b26\u901a\u8fc7\u5305\u62ec\u6240\u6709\u5728 TABLE1 \u4e2d\u4f46\u4e0d\u5728 TABLE2 \u4e2d\u7684\u884c\u5e76\u6d88\u9664\u6240\u6709\u91cd\u590d\u884c\u800c\u6d3e\u751f\u51fa\u4e00\u4e2a\u7ed3\u679c\u8868\u3002\u5f53 ALL \u968f EXCEPT \u4e00\u8d77\u4f7f\u7528\u65f6 (EXCEPT ALL)\uff0c\u4e0d\u6d88\u9664\u91cd\u590d\u884c\u3002
\nC\uff1a INTERSECT \u8fd0\u7b97\u7b26
\nINTERSECT<\/strong> \u8fd0\u7b97\u7b26\u901a\u8fc7\u53ea\u5305\u62ec TABLE1 \u548c TABLE2 \u4e2d\u90fd\u6709\u7684\u884c\u5e76\u6d88\u9664\u6240\u6709\u91cd\u590d\u884c\u800c\u6d3e\u751f\u51fa\u4e00\u4e2a\u7ed3\u679c\u8868\u3002\u5f53 ALL<\/strong> \u968f INTERSECT \u4e00\u8d77\u4f7f\u7528\u65f6 (INTERSECT ALL)\uff0c\u4e0d\u6d88\u9664\u91cd\u590d\u884c\u3002
\n\u6ce8\uff1a<\/strong>\u4f7f\u7528\u8fd0\u7b97\u8bcd\u7684\u51e0\u4e2a\u67e5\u8be2\u7ed3\u679c\u884c\u5fc5\u987b\u662f\u4e00\u81f4\u7684\u3002
\n12<\/strong>\u3001\u8bf4\u660e\uff1a\u4f7f\u7528\u5916\u8fde\u63a5
\n<\/strong>A\u3001left \uff08outer\uff09 join<\/strong>\uff1a
\n\u5de6\u5916\u8fde\u63a5\uff08\u5de6\u8fde\u63a5\uff09\uff1a\u7ed3\u679c\u96c6\u51e0\u5305\u62ec\u8fde\u63a5\u8868\u7684\u5339\u914d\u884c\uff0c\u4e5f\u5305\u62ec\u5de6\u8fde\u63a5\u8868\u7684\u6240\u6709\u884c\u3002
\nSQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c
\nB\uff1aright \uff08outer\uff09 join: <\/strong>
\n\u53f3\u5916\u8fde\u63a5(\u53f3\u8fde\u63a5)\uff1a\u7ed3\u679c\u96c6\u65e2\u5305\u62ec\u8fde\u63a5\u8868\u7684\u5339\u914d\u8fde\u63a5\u884c\uff0c\u4e5f\u5305\u62ec\u53f3\u8fde\u63a5\u8868\u7684\u6240\u6709\u884c\u3002
\nC\uff1afull\/cross \uff08outer\uff09 join<\/strong>\uff1a
\n\u5168\u5916\u8fde\u63a5\uff1a\u4e0d\u4ec5\u5305\u62ec\u7b26\u53f7\u8fde\u63a5\u8868\u7684\u5339\u914d\u884c\uff0c\u8fd8\u5305\u62ec\u4e24\u4e2a\u8fde\u63a5\u8868\u4e2d\u7684\u6240\u6709\u8bb0\u5f55\u3002
\n12<\/strong>\u3001\u5206\u7ec4:Group by:
\n<\/strong>\u4e00\u5f20\u8868\uff0c\u4e00\u65e6\u5206\u7ec4 \u5b8c\u6210\u540e\uff0c\u67e5\u8be2\u540e\u53ea\u80fd\u5f97\u5230\u7ec4\u76f8\u5173\u7684\u4fe1\u606f\u3002
\n\u7ec4\u76f8\u5173\u7684\u4fe1\u606f\uff1a<\/strong>\uff08\u7edf\u8ba1\u4fe1\u606f\uff09 count,sum,max,min,avg \u00a0<\/strong>\u5206\u7ec4\u7684\u6807\u51c6)
\n<\/strong>\u00a0\u00a0\u5728SQLServer\u4e2d\u5206\u7ec4\u65f6\uff1a\u4e0d\u80fd\u4ee5text,ntext,image\u7c7b\u578b\u7684\u5b57\u6bb5\u4f5c\u4e3a\u5206\u7ec4\u4f9d\u636e
\n\u5728selecte\u7edf\u8ba1\u51fd\u6570\u4e2d\u7684\u5b57\u6bb5\uff0c\u4e0d\u80fd\u548c\u666e\u901a\u7684\u5b57\u6bb5\u653e\u5728\u4e00\u8d77\uff1b<\/strong><\/p>\n

<\/a>13\u3001\u5bf9\u6570\u636e\u5e93\u8fdb\u884c\u64cd\u4f5c\uff1a
\n\u5206\u79bb\u6570\u636e\u5e93<\/strong>\uff1a sp_detach_db; \u9644\u52a0\u6570\u636e\u5e93<\/strong>\uff1asp_attach_db <\/strong>\u540e\u63a5\u8868\u660e\uff0c\u9644\u52a0\u9700\u8981\u5b8c\u6574\u7684\u8def\u5f84\u540d
\n14.<\/strong>\u5982\u4f55\u4fee\u6539\u6570\u636e\u5e93\u7684\u540d\u79f0:<\/strong>
\nsp_renamedb ‘old_name’, ‘new_name’<\/p>\n

\u00a0<\/strong><\/p>\n

<\/a>\u4e8c\u3001\u63d0\u5347<\/strong><\/p>\n

<\/a>1\u3001\u8bf4\u660e\uff1a\u590d\u5236\u8868(\u53ea\u590d\u5236\u7ed3\u6784,\u6e90\u8868\u540d\uff1aa \u65b0\u8868\u540d\uff1ab) (Access\u53ef\u7528)
\n\u6cd5\u4e00\uff1a<\/strong>select * into b from a where 1<>1\uff08\u4ec5\u7528\u4e8eSQlServer\uff09
\n\u6cd5\u4e8c\uff1a<\/strong>select top 0 * into b from a
\n2\u3001\u8bf4\u660e\uff1a\u62f7\u8d1d\u8868(\u62f7\u8d1d\u6570\u636e,\u6e90\u8868\u540d\uff1aa \u76ee\u6807\u8868\u540d\uff1ab) (Access\u53ef\u7528)
\n<\/strong>insert into b(a, b, c) select d,e,f from b;<\/p>\n

<\/a>3\u3001\u8bf4\u660e\uff1a\u8de8\u6570\u636e\u5e93\u4e4b\u95f4\u8868\u7684\u62f7\u8d1d(\u5177\u4f53\u6570\u636e\u4f7f\u7528\u7edd\u5bf9\u8def\u5f84) (Access\u53ef\u7528)
\n<\/strong>insert into b(a, b, c) select d,e,f from b in \u2018\u5177\u4f53\u6570\u636e\u5e93\u2019 where \u6761\u4ef6
\n\u4f8b\u5b50\uff1a..from b in ‘”&Server.MapPath(“.”)&”\\data.mdb” &”‘ where..<\/p>\n

<\/a>4\u3001\u8bf4\u660e\uff1a\u5b50\u67e5\u8be2(\u8868\u540d1\uff1aa \u8868\u540d2\uff1ab)
\n<\/strong>select a,b,c from a where a IN (select d from b ) \u6216\u8005: select a,b,c from a where a IN (1,2,3)<\/p>\n

<\/a>5\u3001\u8bf4\u660e\uff1a\u663e\u793a\u6587\u7ae0\u3001\u63d0\u4ea4\u4eba\u548c\u6700\u540e\u56de\u590d\u65f6\u95f4
\n<\/strong>select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b<\/p>\n

<\/a>6\u3001\u8bf4\u660e\uff1a\u5916\u8fde\u63a5\u67e5\u8be2(\u8868\u540d1\uff1aa \u8868\u540d2\uff1ab)
\n<\/strong>select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c<\/p>\n

<\/a>7\u3001\u8bf4\u660e\uff1a\u5728\u7ebf\u89c6\u56fe\u67e5\u8be2(\u8868\u540d1\uff1aa )
\n<\/strong>select * from (SELECT a,b,c FROM a) T where t.a > 1;<\/p>\n

<\/a>8\u3001\u8bf4\u660e\uff1abetween\u7684\u7528\u6cd5,between\u9650\u5236\u67e5\u8be2\u6570\u636e\u8303\u56f4\u65f6\u5305\u62ec\u4e86\u8fb9\u754c\u503c,not between\u4e0d\u5305\u62ec
\n<\/strong>select * from table1 where time between time1 and time2
\nselect a,b,c, from table1 where a not between \u6570\u503c1 and \u6570\u503c2<\/p>\n

<\/a>9\u3001\u8bf4\u660e\uff1ain \u7684\u4f7f\u7528\u65b9\u6cd5
\n<\/strong>select * from table1 where a [not] in (\u2018\u503c1\u2019,\u2019\u503c2\u2019,\u2019\u503c4\u2019,\u2019\u503c6\u2019)<\/p>\n

<\/a>10\u3001\u8bf4\u660e\uff1a\u4e24\u5f20\u5173\u8054\u8868\uff0c\u5220\u9664\u4e3b\u8868\u4e2d\u5df2\u7ecf\u5728\u526f\u8868\u4e2d\u6ca1\u6709\u7684\u4fe1\u606f
\n<\/strong>delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )<\/p>\n

<\/a>11\u3001\u8bf4\u660e\uff1a\u56db\u8868\u8054\u67e5\u95ee\u9898\uff1a
\n<\/strong>select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where …..<\/p>\n

<\/a>12\u3001\u8bf4\u660e\uff1a\u65e5\u7a0b\u5b89\u6392\u63d0\u524d\u4e94\u5206\u949f\u63d0\u9192
\n<\/strong>SQL: select * from \u65e5\u7a0b\u5b89\u6392 where datediff(‘minute’,f\u5f00\u59cb\u65f6\u95f4,getdate())>5<\/p>\n

<\/a>13<\/strong>\u3001\u8bf4\u660e\uff1a\u4e00\u6761<\/strong>sql <\/strong>\u8bed\u53e5\u641e\u5b9a\u6570\u636e\u5e93\u5206\u9875<\/strong>
\n<\/strong>select top 10 b.* from (select top 20 \u4e3b\u952e\u5b57\u6bb5,\u6392\u5e8f\u5b57\u6bb5 from \u8868\u540d order by \u6392\u5e8f\u5b57\u6bb5 desc) a,\u8868\u540d b where b.\u4e3b\u952e\u5b57\u6bb5 = a.\u4e3b\u952e\u5b57\u6bb5 order by a.\u6392\u5e8f\u5b57\u6bb5
\n\u5177\u4f53\u5b9e\u73b0\uff1a<\/strong>
\n\u5173\u4e8e\u6570\u636e\u5e93\u5206\u9875\uff1a<\/p>\n

declare @start int,@end int<\/p>\n

@sql\u00a0 nvarchar(600)<\/p>\n

set @sql=\u2019select top\u2019+str(@end-@start+1)+\u2019+from T where rid not in(select top\u2019+str(@str-1)+\u2019Rid from T where Rid>-1)\u2019<\/p>\n

exec sp_executesql @sql
\n\u6ce8\u610f\uff1a\u5728<\/strong>top<\/strong>\u540e\u4e0d\u80fd\u76f4\u63a5\u8ddf\u4e00\u4e2a\u53d8\u91cf\uff0c\u6240\u4ee5\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\u53ea\u6709\u8fd9\u6837\u7684\u8fdb\u884c\u7279\u6b8a\u7684\u5904\u7406\u3002<\/strong>Rid<\/strong>\u4e3a\u4e00\u4e2a\u6807\u8bc6\u5217\uff0c\u5982\u679c<\/strong>top<\/strong>\u540e\u8fd8\u6709\u5177\u4f53\u7684\u5b57\u6bb5\uff0c\u8fd9\u6837\u505a\u662f\u975e\u5e38\u6709\u597d\u5904\u7684\u3002\u56e0\u4e3a\u8fd9\u6837\u53ef\u4ee5\u907f\u514d<\/strong> top<\/strong>\u7684\u5b57\u6bb5\u5982\u679c\u662f\u903b\u8f91\u7d22\u5f15\u7684\uff0c\u67e5\u8be2\u7684\u7ed3\u679c\u540e\u5b9e\u9645\u8868\u4e2d\u7684\u4e0d\u4e00\u81f4\uff08<\/strong>\u903b\u8f91\u7d22\u5f15\u4e2d\u7684\u6570\u636e\u6709\u53ef\u80fd\u548c\u6570\u636e\u8868\u4e2d\u7684\u4e0d\u4e00\u81f4\uff0c\u800c\u67e5\u8be2\u65f6\u5982\u679c\u5904\u5728\u7d22\u5f15\u5219\u9996\u5148\u67e5\u8be2\u7d22\u5f15<\/strong>\uff09<\/strong><\/p>\n

<\/a>14\u3001\u8bf4\u660e\uff1a\u524d10\u6761\u8bb0\u5f55
\n<\/strong>select top 10 * form table1 where \u8303\u56f4<\/p>\n

<\/a>15\u3001\u8bf4\u660e\uff1a\u9009\u62e9\u5728\u6bcf\u4e00\u7ec4b\u503c\u76f8\u540c\u7684\u6570\u636e\u4e2d\u5bf9\u5e94\u7684a\u6700\u5927\u7684\u8bb0\u5f55\u7684\u6240\u6709\u4fe1\u606f(\u7c7b\u4f3c\u8fd9\u6837\u7684\u7528\u6cd5\u53ef\u4ee5\u7528\u4e8e\u8bba\u575b\u6bcf\u6708\u6392\u884c\u699c,\u6bcf\u6708\u70ed\u9500\u4ea7\u54c1\u5206\u6790,\u6309\u79d1\u76ee\u6210\u7ee9\u6392\u540d,\u7b49\u7b49.)
\n<\/strong>select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b)<\/p>\n

<\/a>16\u3001\u8bf4\u660e\uff1a\u5305\u62ec\u6240\u6709\u5728 TableA \u4e2d\u4f46\u4e0d\u5728 TableB\u548cTableC \u4e2d\u7684\u884c\u5e76\u6d88\u9664\u6240\u6709\u91cd\u590d\u884c\u800c\u6d3e\u751f\u51fa\u4e00\u4e2a\u7ed3\u679c\u8868
\n<\/strong>(select a from tableA ) except (select a from tableB) except (select a from tableC)<\/p>\n

<\/a>17\u3001\u8bf4\u660e\uff1a\u968f\u673a\u53d6\u51fa10\u6761\u6570\u636e
\n<\/strong>select top 10 * from tablename order by newid()<\/strong><\/p>\n

<\/a>18\u3001\u8bf4\u660e\uff1a\u968f\u673a\u9009\u62e9\u8bb0\u5f55
\n<\/strong>select newid()<\/p>\n

<\/a>19\u3001\u8bf4\u660e\uff1a\u5220\u9664\u91cd\u590d\u8bb0\u5f55
\n1),<\/strong>delete from tablename where id not in (select max(id) from tablename group by col1,col2,…)
\n2)<\/strong>,select distinct * into temp from tablename
\ndelete from tablename
\ninsert into tablename select * from temp
\n\u8bc4\u4ef7\uff1a \u8fd9\u79cd\u64cd\u4f5c\u7275\u8fde\u5927\u91cf\u7684\u6570\u636e\u7684\u79fb\u52a8\uff0c\u8fd9\u79cd\u505a\u6cd5\u4e0d\u9002\u5408\u5927\u5bb9\u91cf\u4f46\u6570\u636e\u64cd\u4f5c
\n3),\u4f8b\u5982\uff1a\u5728\u4e00\u4e2a\u5916\u90e8\u8868\u4e2d\u5bfc\u5165\u6570\u636e\uff0c\u7531\u4e8e\u67d0\u4e9b\u539f\u56e0\u7b2c\u4e00\u6b21\u53ea\u5bfc\u5165\u4e86\u4e00\u90e8\u5206\uff0c\u4f46\u5f88\u96be\u5224\u65ad\u5177\u4f53\u4f4d\u7f6e\uff0c\u8fd9\u6837\u53ea\u6709\u5728\u4e0b\u4e00\u6b21\u5168\u90e8\u5bfc\u5165\uff0c\u8fd9\u6837\u4e5f\u5c31\u4ea7\u751f\u597d\u591a\u91cd\u590d\u7684\u5b57\u6bb5\uff0c\u600e\u6837\u5220\u9664\u91cd\u590d\u5b57\u6bb5<\/strong><\/p>\n

alter table tablename
\n–\u6dfb\u52a0\u4e00\u4e2a\u81ea\u589e\u5217
\nadd\u00a0 column_b int identity(1,1)
\ndelete from tablename where column_b not in(
\nselect max(column_b)\u00a0 from tablename group by column1,column2,…)
\nalter table tablename drop column column_b<\/p>\n

<\/a>20\u3001\u8bf4\u660e\uff1a\u5217\u51fa\u6570\u636e\u5e93\u91cc\u6240\u6709\u7684\u8868\u540d
\n<\/strong>select name from sysobjects where type=’U’ \/\/ U\u4ee3\u8868\u7528\u6237<\/p>\n

<\/a>21\u3001\u8bf4\u660e\uff1a\u5217\u51fa\u8868\u91cc\u7684\u6240\u6709\u7684\u5217\u540d
\n<\/strong>select name from syscolumns where id=object_id(‘TableName’)<\/p>\n

<\/a>22\u3001\u8bf4\u660e\uff1a\u5217\u793atype\u3001vender\u3001pcs\u5b57\u6bb5\uff0c\u4ee5type\u5b57\u6bb5\u6392\u5217\uff0ccase\u53ef\u4ee5\u65b9\u4fbf\u5730\u5b9e\u73b0\u591a\u91cd\u9009\u62e9\uff0c\u7c7b\u4f3cselect \u4e2d\u7684case\u3002
\n<\/strong>select type,sum(case vender when ‘A’ then pcs else 0 end),sum(case vender when ‘C’ then pcs else 0 end),sum(case vender when ‘B’ then pcs else 0 end) FROM tablename group by type
\n\u663e\u793a\u7ed3\u679c\uff1a
\ntype vender pcs
\n<\/strong>\u7535\u8111 A 1
\n\u7535\u8111 A 1
\n\u5149\u76d8 B 2
\n\u5149\u76d8 A 2
\n\u624b\u673a B 3
\n\u624b\u673a C 3<\/p>\n

<\/a>23\u3001\u8bf4\u660e\uff1a\u521d\u59cb\u5316\u8868table1<\/strong><\/p>\n

TRUNCATE TABLE table1<\/p>\n

<\/a>24\u3001\u8bf4\u660e\uff1a\u9009\u62e9\u4ece10\u523015\u7684\u8bb0\u5f55
\n<\/strong>select top 5 * from (select top 15 * from table order by id asc) table_\u522b\u540d order by id desc<\/p>\n","protected":false},"excerpt":{"rendered":"

\u7ecf\u5178SQL\u8bed\u53e5<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[61],"tags":[62],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/737"}],"collection":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=737"}],"version-history":[{"count":1,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/737\/revisions"}],"predecessor-version":[{"id":738,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/737\/revisions\/738"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=737"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=737"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=737"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}