SQLÐÐתÁдúÂë
1. SQLÐÐתÁдúÂë
-
-
±íÀïÃæÓÐÕâôһ×éÊý¾Ý:
code price
'MCU0-3' 15
'MCU0-3' 20
'MCU0-3' 22
'MCU3-15' 17
'MCU3-15' 16
'MCU3-15' -10
'MCU3-15' 50
'MCU3-27' 99
'MCU3-27' 96
'MCU3-27' 54
'MCU3-27' 14
'MCU3-27' 46
'MCU3-27' 86
ÏÖÔÚÐèÒªµÃµ½ÕâÑùµÄ½á¹û:
MCU0-3 MCU3-15 MCU3-27
15 17 99
20 16 96
22 -10 54
null 50 14
null null 46
null null 86
SQLÓï¾äÊÇÕâÑùдµÄ:
SELECT ID = IDENTITY(INT, 1, 1), price into #T1 from [table] where code = 'MCU0-3'
SELECT ID = IDENTITY(INT, 1, 1), price into #T2 from [table] where code = 'MCU3-15'
SELECT ID = IDENTITY(INT, 1, 1), price into #T3 from [table]
Ïà¹ØÎĵµ£º
¹¤×÷ÖÐÅöµ½µÄС¼¼ÇÉ£¬±ÈÈç˵ҪÓÃÊý¾Ý±íÀïÈ¡³ö×¢²áÓû§µÄ×ÊÁÏ£¬ÐÔ±ðΪ1ÔòÏÔʾΪÄÐÉú£»ÐÔ±ðΪ2ÔòÏÔʾΪŮÉú£»ÒÔǰ¶¼ÊÇ´Ó±íÀïÈ¡³öÊý¾Ý£¬È»ºóÔÙÓôúÂë½øÐÐÅжϣ¬Îª1ÔòÏÔʾΪÄÐÉú£»Îª2ÔòÏÔʾΪŮÉú£»Æäʵµ¥ÓÃSQLÓï¾ä¾Í¿ÉÒÔ×öµ½£¬ÈçÏ£º
Ö±½ÓʹÓÃcase when else Óï¾ä
Case¾ßÓÐÁ½ÖÖ¸ñʽ¡£¼òµ¥Caseº¯ÊýºÍCaseË ......
Êý¾Ý¿â¿ìÕÕÊÇMSSQL2005µÄй¦ÄÜ£¬½öÔÚ Microsoft SQL Server 2005 Enterprise Edition ÖпÉÓ᣶øÇÒSQL Server Management Studio ²»Ö§³Ö´´½¨Êý¾Ý¿â¿ìÕÕ£¬´´½¨¿ìÕÕµÄΨһ·½Ê½ÊÇʹÓà Transact-SQL¡£
Êý¾Ý¿â¿ìÕÕÊÇÊý¾Ý¿â£¨³ÆÎª“Ô´Êý¾Ý¿â”£©µÄÖ»¶Á¾²Ì¬ÊÓͼ¡£ÔÚ´´½¨Ê±£¬Ã¿¸öÊý¾Ý¿â¿ìÕÕÔÚÊÂÎñÉ϶¼ÓëÔ´Êý¾Ý¿âÒ»Ö ......
»ù±¾µÄSql±àдעÒâÊÂÏî
¾¡Á¿ÉÙÓÃIN²Ù×÷·û£¬»ù±¾ÉÏËùÓеÄIN²Ù×÷·û¶¼¿ÉÒÔÓÃEXISTS´úÌæ¡£
²»ÓÃNOT IN²Ù×÷·û£¬¿ÉÒÔÓÃNOT EXISTS»òÕßÍâÁ¬½Ó+Ìæ´ú¡£
OracleÔÚÖ´ÐÐIN×Ó²éѯʱ£¬Ê×ÏÈÖ´ÐÐ×Ó²éѯ£¬½«²éѯ½á¹û·ÅÈëÁÙʱ±íÔÙÖ´ÐÐÖ÷²éѯ¡£¶øEXISTÔòÊÇÊ×Ïȼì²éÖ÷²éѯ£¬È»ºóÔËÐÐ×Ó²éѯֱµ½ÕÒµ½
µÚÒ»¸öÆ¥ÅäÏî¡£NOT EXISTS±ÈNOT INЧÂÊÉ ......
×¢£º³ö´¦ÒѲ»¿É¿¼£¬²»¹ý£¬ÆäÖв»ÉÙÓï¾ä»¹ÊÇÂù¾«ÃîµÄ¡£
Student(S#(ѧºÅ),Sname(ÐÕÃû),Sage(ÄêÁä),Ssex(ÐÔ±ð)) ѧÉú±í
Course(C#(¿Î³Ì±àºÅ),Cname(¿Î³ÌÃû³Æ),T#(ÀÏʦ±àºÅ)) ¿Î³Ì±í
SC(S#(ѧºÅ),C#(¿Î³Ì±àºÅ),score(·ÖÊý)) ³É¼¨±í
Teacher(T#(ÀÏʦ±àºÅ),TnameSname(ÐÕÃû)) ½Ìʦ±í
ÎÊÌ⣺
1¡¢²éѯ“001” ......