允许将显式值插入表的标识列中。
语法
SET IDENTITY_INSERT [ database.[ owner.] ] { table } { ON | OFF }
参数
database
是指定的表所驻留的数据库名称。
owner
是表所有者的名称。
table
是含有标识列的表名。
注释
任何时候，会话中只有一个表的 IDENTITY_INSERT 属性可以设置为 ON。如果某个表已将此属性设置为 ON，并且为另一个表发出了 SET IDENTITY_INSERT ON 语句，则 Microsoft® SQL Server™ 返回一个错误信息，指出 SET IDENTITY_INSERT 已设置为 ON 并报告此属性已设置为 ON 的表。
如果插入值大于表的当前标识值，则 SQL Server 自动将新插入值作为当前标识值使用。
SET IDENTITY_INSERT 的设置是在执行或运行时设置，而不是在分析时设置。
权限
执行权限默认授予 sysadmin 固定服务器角色和 db_owner 及 db_ddladmin 固定数据库角色以及对象所有者。
示例
下例创建一个含有标识列的表，并显示如何使用 SET IDENTITY_INSERT 设置填充由 DELETE 语句导致的标识值中的空隙。
代码
-- Create products table.
CREATE TABLE products (id int IDENTITY PRIMARY KEY, product varchar(40))
GO
-- Inserting values into products table.
INSERT INTO products (product) VALUES ('screwdriver')
INSERT INTO products (product) VALUES ('hammer')
INSERT INTO products (product) VALUES ('saw')
INSERT INTO products (product) VALUES ('shovel')
GO
-- Create a gap in the identity values.
DELETE products
WHERE product = 'saw'
GO
SELECT *
FROM products
GO
-- Attempt to insert an explicit ID value of 3;
-- should return a warning.
INSERT INTO products (id, product) VALUES(3, 'garden shovel')
GO
-- SET IDENTITY_INSERT to ON.
SET IDENTITY_INSERT products ON
GO
-- Attempt to insert an explicit ID value of 3
INSERT INTO products (id, product) VALUES(3, 'garden shovel').
GO
SELECT *
FROM products
GO
-- Drop products table.
DROP TABLE products
GO
CREATE TABLE products (id int IDENTITY PRIMARY KEY, product varchar(40))
GO
-- Inserting values into products table.
INSERT INTO products (product) VALUES ('screwdriver')
INSERT INTO products (product) VALUES ('hammer')
INSERT INTO products (product) VALUES ('saw')
INSERT INTO products (product) VALUES ('shovel')
GO
-- Create a gap in the identity values.
DELETE products
WHERE product = 'saw'
GO
SELECT *
FROM products
GO
-- Attempt to insert an explicit ID value of 3;
-- should return a warning.
INSERT INTO products (id, product) VALUES(3, 'garden shovel')
GO
-- SET IDENTITY_INSERT to ON.
SET IDENTITY_INSERT products ON
GO
-- Attempt to insert an explicit ID value of 3
INSERT INTO products (id, product) VALUES(3, 'garden shovel').
GO
SELECT *
FROM products
GO
-- Drop products table.
DROP TABLE products
GO
