Question

I am trying to do record inserts on a table where the Primary Key is an Identity field.

I have tried calling
mycontext.ExecuteCommand("SET identity_insert myTable ON")
but this doesn’t do any good.

I get an error saying IDENTITY_INSERT is OFF when I submit changes.

How can I turn it ON from the C# code before I submit changes?

EDIT

I have read that this is because ExecuteCommand’s code gets executed in a different session.

EDIT 2

Is there any way I can execute some DDL to remove the Identity Specification from my C# code, do the inserts, and then turn Identity Specification back on?

Answer 1

You need to do all the steps in a single T-SQL code block – which is going to be really hard if not impossible if you want to turn it on, then execute your LINQ-to-SQL query, and then turn it back off 🙁

The only real solution I see is to package up the entire SQL into a SQL statement and execute that:

SET IDENTITY_INSERT MyTable ON

(do your update here)

SET IDENTITY_INSERT MyTable OFF

and execute that as a single code block using .ExecuteContext()

Marc

PS: for your EDIT#2 : no, unfortunately, there’s no (easy) way to remove the identity from a column, and turn it back on. Basicall you’d have to create a new column without the IDENTITY, copy the values over, drop the IDENTITY column and then do the same backwards when you’re done – sorry! 🙁

PS #2: this really begs the question: what on earth to do need to do an “identity insert” for? On a regular basis, from an app? Granted – you might run into this need once in a while, but I’d always do this separately, in SQL Mgmt Studio – certainly not in my app….. (just curious what your use case / motivation is).