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ûÓÐ,ÓÃcase when À´´úÌæ¾ÍÐÐÁË.
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select getdate() as ÈÕÆÚ,case month(getdate())
when 11 then 'ʮһ'
when 12 then 'Ê®¶þ'
else substring('Ò»¶þÈýËÄÎåÁùÆ߰˾ÅÊ®', month(getdate()),1)
end+'ÔÂ' as Ô·Ý
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SELECT <myColumnSpec> =
CASE
WHEN <A> THEN <somethingA>
WHEN <B> THEN <somethingB>
ELSE <somethingE>
END
ÔÚÉÏÃæµÄ´úÂëÖÐÐèÒªÓþßÌåµÄ²ÎÊý´úÌæ¼âÀ¨ºÅÖеÄÄÚÈÝ¡£ÏÂÃæÊÇÒ»¸ö¼òµ¥µÄÀý×Ó£º
USE pubs
GO
SELECT
Title,
'Price Range' =
CASE
WHEN price IS NULL THEN 'Unpriced'
WHEN price < 10 THEN 'Bargain'
WHEN price BETWEEN 10 and 20 THEN 'Average'
ELSE 'Gift to impress relatives'
END
from titles
ORDER BY price
GO
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SELECT 'Number of Titles', Count(*)
from titles
GROUP BY
CASE
WHEN price IS NULL THEN 'Unpriced'
WHEN price < 10 THEN 'Bargain'
&nb
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& ......
/* °üº¬CÍ·Îļþ */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/* °üº¬SQLCAÍ·Îļþ */
EXEC SQL INCLUDE sqlca;
EXEC SQL INCLUDE sqlda;
int main()
{
EXEC SQL BEGIN DECLARE SECTION;
int money;
......
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DCL—Êý¾Ý¿ØÖÆÓïÑÔ(GRANT£¬REVOKE£¬COMMIT£¬ROLLBACK)
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--SQL ËÙ²éÊÖ²á
/*******************************************/
SELECT
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--Óï·¨£º
SELECT column_name(s) from table_name
--Ö÷Òª×Ö¾ä¿ÉժҪΪ:
SELECT select_list [INTO new_table]
from table_source
[WHERE search_condition]
[GROUP BY group_by_expression]
[HAVING s ......
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