Question

declare @cid int

set @cid=(select ISNULL(MAX(cid),0)+1 from CustInfo)
insert into CustInfo(CID,CTypeId,CustNo,Regdate,
                     DOB,CCertID,CCertNo,CompId,PostedBy,PostedOn) 
(select @cid,1,0,'2012-9-10',
        dob,ccertid,ccertno,0,null,null 
 from updateCust3)

I have used above code to insert values from table updateCust3 to table UpdateCustInfo.
In this case the CID field should be incremented by one at each insert. I have used the above code but the cid doesn’t seem to increase so the error is duplicate value for the primary key. So how can I increase the value of cid? Since the change in table property is not allowed I cannot use identity property.

Answer 1

try this:

declare @cid int

set @cid=(select ISNULL(MAX(cid),0)+1 from CustInfo)
insert into CustInfo(CID,CTypeId,CustNo,Regdate,
                     DOB,CCertID,CCertNo,CompId,PostedBy,PostedOn) 
select @cid+row_number() over (order by (select 0)),1,0,'2012-9-10',
        dob,ccertid,ccertno,0,null,null 
 from updateCust3)

Edit: As MikaelEriksson mentioned in the comment, this has the risk, if you users are simultaneously trying to update the table, it will error out..