帮忙写一个SQL语句。 Update TBL1
Set Field1=NULL,
Field2 = NULL
FROM TBL1,TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id上面这个语句中,需要判断
if tbl2.fid = a
Field1=NULL,
Field2 = NULL
else
Field1=@f1
Field2 = @f2
这个SQL如何写?
Set Field1=NULL,
Field2 = NULL
FROM TBL1,TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id上面这个语句中,需要判断
if tbl2.fid = a
Field1=NULL,
Field2 = NULL
else
Field1=@f1
Field2 = @f2
这个SQL如何写?
Set Field1=case when tbl2.fid = 'a' then null else @f1 end ,
Field2 = case when tbl2.fid = 'a' then null else @f2 end
FROM TBL1,TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id
Set Field1=case when tbl2.fid = 'a' then NULL else @f1 end,
Field2 = case when tbl2.fid = 'a' then NULL else @f2 end
FROM TBL1,TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id
Set Field1=NULL,
Field2 = NULL
FROM TBL1,TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id and tbl2.fid = a
Update TBL1
Set Field1=@f1
Field2 = @f2
FROM TBL1,TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id and tbl2.fid <> a
Set Field1=case Field1 when a then null else Field1 end,
Field2 = case Field2 when a then null else Field2 end
FROM TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id
Set Field1=case when tbl2.fid = 'a' then NULL else @f1 end,
Field2 = case when tbl2.fid = 'a' then NULL else @f2 end
FROM TBL1,TBL2
WHERE TBL1.id= @p and tbl1.id = tbl2.id
Set Field1=case when b.fid = 'a' then null else @f1 end ,
Field2=case when b.fid = 'a' then null else @f2 end
FROM TBL1 a,TBL2 b
WHERE a.id= @p and a.id = b.id