How do you check if IDENTITY_INSERT is set to ON or OFF in SQL Server?

Question

I\'ve searched for this, but threads in which it appeared tended to have answers from people who didn\'t understand the question.

Take the following syntax:

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Answer 1

Here is my solution. It is very similar to @jmoreno's answer.

You would call it like this

DECLARE @IdentityInsert VARCHAR(20)
EXEC dbo.GetIdentityInsert 'YourDb', 'YourSchema', 'YourTable', @IdentityInsert OUT
SELECT @IdentityInsert 

This returns a 1-row recordset with column name IDENTITY_INSERT, that can be either ON, OFF, or NO_IDENTITY (if the given table doesn't have an identity column). It also sets the output parameter @IdentityInsert. So you can adjust the code to whichever method you prefer.

It would be nice to get this into a user-defined function, but unfortunately I couldn't find a way to avoid the TRY..CATCH block, which you cannot use in user-defined functions.

-- ================================================================================
-- Check whether the table specified has its IDENTITY_INSERT set to ON or OFF.
-- If the table does not have an identity column, NO_IDENTITY is returned.
-- Tested on SQL 2008.
-- ================================================================================
CREATE PROCEDURE dbo.GetIdentityInsert

      @dbname sysname
    , @schemaname sysname
    , @table sysname
    , @IdentityInsert VARCHAR(20) OUTPUT

AS

BEGIN

    SET NOCOUNT ON

    DECLARE @OtherTable nvarchar(max)
    DECLARE @DbSchemaTable nvarchar(max)

    DECLARE @ErrorMessage NVARCHAR(4000);
    DECLARE @ErrorSeverity INT;
    DECLARE @ErrorState INT;
    DECLARE @ErrorNumber INT;
    DECLARE @object_id INT;

    SET @DbSchemaTable = @dbname + '.' + @schemaname + '.' + @table

    SET @object_id = OBJECT_ID(@DbSchemaTable)
    IF @object_id IS NULL
    BEGIN
        RAISERROR('table %s doesn''t exist', 16, 1, @DbSchemaTable)
        RETURN
    END


    BEGIN TRY

        SET @object_id = OBJECT_ID(@DbSchemaTable)

        IF OBJECTPROPERTY(@object_id,'TableHasIdentity') = 0
        BEGIN
            SET @IdentityInsert = 'NO_IDENTITY'
        END
        ELSE
        BEGIN
            -- Attempt to set IDENTITY_INSERT on a temp table. This will fail if any other table
            -- has IDENTITY_INSERT set to ON, and we'll process that in the CATCH
            CREATE TABLE #GetIdentityInsert(ID INT IDENTITY)
            SET IDENTITY_INSERT #GetIdentityInsert ON
            SET IDENTITY_INSERT #GetIdentityInsert OFF
            DROP TABLE #GetIdentityInsert

            -- It didn't fail, so IDENTITY_INSERT on @table must set to OFF
            SET @IdentityInsert = 'OFF'
        END
    END TRY


    BEGIN CATCH

        SELECT 
            @ErrorMessage = ERROR_MESSAGE(),
            @ErrorSeverity = ERROR_SEVERITY(),
            @ErrorState = ERROR_STATE(),
            @ErrorNumber = ERROR_NUMBER();

        IF @ErrorNumber = 8107  --IDENTITY_INSERT is already set on a table
        BEGIN
            SET @OtherTable = SUBSTRING(@ErrorMessage, CHARINDEX(char(39), @ErrorMessage)+1, 2000)
            SET @OtherTable = SUBSTRING(@OtherTable, 1, CHARINDEX(char(39), @OtherTable)-1)

            IF @OtherTable = @DbSchemaTable 
            BEGIN
                -- If the table name is the same, then IDENTITY_INSERT on @table must be ON
                SET @IdentityInsert = 'ON'
            END
            ELSE
            BEGIN
                -- If the table name is different, then IDENTITY_INSERT on @table must be OFF
                SET @IdentityInsert =  'OFF'
            END
        END
        ELSE
        BEGIN
            RAISERROR (@ErrorNumber, @ErrorMessage, @ErrorSeverity, @ErrorState);
            --THROW     Use this if SQL 2012 or higher
        END

    END CATCH

    SELECT [IDENTITY_INSERT] = @IdentityInsert
END
GO