sybase sql һ��

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1 total messages Started by missing Sun, 11 Jan 1998 00:00

#10483

Author: missing
Date: Sun, 11 Jan 1998 00:00

30 lines
1770 bytes

��������sybase T-sql д�����ֵ�����,ϣ���Ұ��æ.
�ְ����������.
�б� test1(a int , b int)
     test2(a int , b int ,c int)
test1��Ψһ����������,test2��(a,b)Ϊ����.
���(a,b)��ֵ������test1 ��,��test2��Ӧ����(a,b,1)
���߽�ԭֵ(a,b,0)��Ϊ(a,b,1).
���ѰѲ����������,�����¾�:
insert into test2
select distinct a,b,1
from test1
where not exists(select 1 from test2
                 where test1.a = test2.a
                   and test1.b = test2.b);
(Ҳ��֪�Ƿ�������)
��Ҫ����޸ĵ�����,��test2 ����(a,b,0),Ҫ���test1�Ƿ���(a,b)��¼
������Ϊ(a,b,1).
��д���������:
update test2
set c = 1
where (a,b) in (select distinct a,b from test1);
����sybase�ļ��ϲ�������֧�ֶ���,ִ��ʱ���﷨��.
������ʲô���֮��?
лл!
(��Ҫ����������ͼ,��Ϊtest1�еļ�¼����ʱ��ܶ�,��test2������
����ʷ,ֻҪ���ʱ(a,b)������test1��,test2��Ҫ����(a,b,1))

--
�� ��Դ: �й�ƴ�BBSվ [bbs.ustc.edu.cn]

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