Check Object

后续版本的 Microsoft SQL Server 将删除该功能。请避免在新的开发工作中使用该功能,并着手修改当前还在使用该功能的应用程序。

The Check object represents the attributes of a single Microsoft SQL Server integrity constraint.

显示当前对象的 SQL-DMO 对象模型

注释

A SQL Server integrity constraint can be defined as part of a CREATE TABLE statement or can be added to, or removed from, a table as part of an ALTER TABLE statement.

With the Check object, you can:

  • Define a new integrity constraint for a SQL Server table.

  • Remove an existing constraint from a SQL Server table.

  • Generate a Transact-SQL script to document an existing integrity constraint.

The Name property represents a constraint name. It is character data and must be unique within a SQL Server database.

To create a SQL Server integrity constraint

  1. Create a Check object.

  2. Set the Name property.

  3. Set the Text property to define the constraint.

    Adding the Check object to its containing collection generates the appropriate CREATE statement. Specify only the integrity test condition in the Text property.

  4. Set the ExcludeReplication property.

  5. Add the Check object to the Checks collection of a Table object.

To remove a SQL Server integrity constraint

  1. Get the appropriate Table object from the Tables collection of a Database object.

  2. Use the BeginAlter method of the Table object to mark the start of alterations on the SQL Server table.

  3. Get the appropriate Check object from the Checks collection of the Table object.

  4. Use the Remove method of the Check object to drop its integrity constraint from the SQL Server table.

  5. Use the DoAlter method of the Table object to submit the change to the instance of SQL Server.