Upravit

Sdílet prostřednictvím

SET IDENTITY_INSERT (Transact-SQL)

  • Článek

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics

Allows explicit values to be inserted into the identity column of a table.

Transact-SQL syntax conventions

Syntax

SET IDENTITY_INSERT [ [ database_name . ] schema_name . ] table_name { ON | OFF }

Arguments

database_name

The name of the database in which the specified table resides.

schema_name

The name of the schema to which the table belongs.

table_name

The name of a table with an identity column.

Remarks

At any time, only one table in a session can have the IDENTITY_INSERT property set to ON. If a table already has this property set to ON, and a SET IDENTITY_INSERT ON statement is issued for another table, SQL Server returns an error message that states SET IDENTITY_INSERT is already ON, and reports the table for which ON is set.

If the value inserted is larger than the current identity value for the table, SQL Server automatically uses the new inserted value as the current identity value.

The setting of SET IDENTITY_INSERT is set at execute or run time and not at parse time.

Permissions

User must own the table or have ALTER permission on the table.

Examples

The following example creates a table with an identity column and shows how the SET IDENTITY_INSERT setting can be used to fill a gap in the identity values caused by a DELETE statement.

USE AdventureWorks2022;
GO

Create tool table.

CREATE TABLE dbo.Tool
(
    ID INT IDENTITY NOT NULL PRIMARY KEY,
    Name VARCHAR (40) NOT NULL
);
GO

Insert values into products table.

INSERT INTO dbo.Tool (Name)
VALUES ('Screwdriver'),
    ('Hammer'),
    ('Saw'),
    ('Shovel');
GO

Create a gap in the identity values.

DELETE dbo.Tool
WHERE Name = 'Saw';
GO

SELECT *
FROM dbo.Tool;
GO

Try to insert an explicit ID value of 3.

INSERT INTO dbo.Tool (ID, Name)
VALUES (3, 'Garden shovel');
GO

The previous INSERT code should return the following error:

An explicit value for the identity column in table 'AdventureWorks2022.dbo.Tool' can only be specified when a column list is used and IDENTITY_INSERT is ON.

Set IDENTITY_INSERT to ON.

SET IDENTITY_INSERT dbo.Tool ON;
GO

Try to insert an explicit ID value of 3.

INSERT INTO dbo.Tool (ID, Name)
VALUES (3, 'Garden shovel');
GO

SELECT *
FROM dbo.Tool;
GO

Drop tool table.

DROP TABLE dbo.Tool;
GO

Related content