在存储过程中,如何实现按条件下移的过程。
比如:
第一条:select * from db1 where aa=1 and bb=2
然后在这个范围内查询第二条语句:
selcet db2.aa,db3.bb from db2,db3 where
db2.cc in (selcet id from db1 where bb=2)
and ..... 不知道我表述的各位高手可否看懂?
补充:就是类似于程序中的条件判断,在第一个条件范围内,加载
其他条件!
比如:
第一条:select * from db1 where aa=1 and bb=2
然后在这个范围内查询第二条语句:
selcet db2.aa,db3.bb from db2,db3 where
db2.cc in (selcet id from db1 where bb=2)
and ..... 不知道我表述的各位高手可否看懂?
补充:就是类似于程序中的条件判断,在第一个条件范围内,加载
其他条件!
那就是用
if EXISTS(select * from db1 where aa=1 and bb=2 )
begin
selcet db2.aa,db3.bb from db2,db3 where
db2.cc in (selcet id from db1 where bb=2)
and .....
end
else if EXISTS(select * from db1 where aa=1 and bb=2 )
begin
selcet db2.aa,db3.bb from db2,db3 where
db2.cc in (selcet id from db1 where bb=2)
and .....
end
.........
不知是不是你要的结果
select @ct=count * from db1 where aa=1 and bb=2;
if @ct>0
declare @count=0;
select @count=count (*) from db1 where aa=1 and bb=2;
if @ct>0
selcet db2.aa,db3.bb from db2,db3 where
db2.cc in (selcet id from db1 where bb=2)
and .....
db2.cc in (selcet id from db1 where bb=2)
and .....
if exists (select db1.id from db1,db2 where db1.id=db2.cc and db1.bb=2)
begin
...
end