What is the difference between Scope_Identity(), Identity(), @@Identity, and Ident_Current()?

Question

I know Scope_Identity(), Identity(), @@Identity, and Ident_Current() all get the value of the identity column, but I woul

Answer 1

Good question.

• @@IDENTITY: returns the last identity value generated on your SQL connection (SPID). Most of the time it will be what you want, but sometimes it isn't (like when a trigger is fired in response to an INSERT, and the trigger executes another INSERT statement).

• SCOPE_IDENTITY(): returns the last identity value generated in the current scope (i.e. stored procedure, trigger, function, etc).

• IDENT_CURRENT(): returns the last identity value for a specific table. Don't use this to get the identity value from an INSERT, it's subject to race conditions (i.e. multiple connections inserting rows on the same table).

• IDENTITY(): used when declaring a column in a table as an identity column.

For more reference, see: http://msdn.microsoft.com/en-us/library/ms187342.aspx.

To summarize: if you are inserting rows, and you want to know the value of the identity column for the row you just inserted, always use SCOPE_IDENTITY().