可以使用 SQL Server Management Studio 或 Transact-SQL 在表中创建检查约束,以指定 SQL Server 的一个或多个列中可接受的数据值。 要详细了解如何添加列约束,请参阅 ALTER TABLE column_constraint。 有关详细信息,请参阅 Unique 约束和 check 约束。 备注 若要查询现有的检查约束,请使用 sys.check_constraints...
可以使用 SQL Server Management Studio 或 Transact-SQL 在表中创建检查约束,以指定 SQL Server 的一个或多个列中可接受的数据值。 要详细了解如何添加列约束,请参阅ALTER TABLE column_constraint。 有关详细信息,请参阅Unique 约束和 check 约束。
You can create a check constraint in a table to specify the data values that are acceptable in one or more columns in SQL Server by using SQL Server Management Studio or Transact-SQL. For more information on adding column constraints, see ALTER TABLE column_constraint. For more information, ...
altertablePersonsaddprimarykey(id_p);altertablePersonsadd constraintuc_PersonIDprimarykey(id_p, lastname); 3)FOREIGN KEY(两种写法) altertableOrdersaddFOREIGNKEY(Id_P)REFERENCESPerson(Id_P);altertableOrdersaddCONSTRAINTfk_PerOrdersFOREIGNKEY(Id_P)REFERENCESPersons(Id_P); 4)CHECK(两种写法) altertable...
To define a CHECK constraint on a column To replace a stored procedure Use an inline function as a filter predicate for a security policy The integration of .NET Framework CLR into SQL Server is discussed in this article. CLR integration doesn't apply to Azure SQL Database. For Azure Synaps...
如果停用條件約束,請使用 CHECK CONSTRAINT *constraint_name* 的ALTER TABLE選項重新啟用條件約束檢查,並使用 WITH CHECK 選項來驗證條件約束。 下列範例會顯示各組有效的條件約束: syntaxsql 複製 { [col < 10], [col between 11 and 20] , [col > 20] } { [col between 11 and 20], [col between ...
You can create a unique constraint in SQL Server by using SQL Server Management Studio or Transact-SQL to ensure no duplicate values are entered in specific columns that don't participate in a primary key. Creating a unique constraint automatically creates a corresponding unique index....
table_constraint 테이블에 추가한 PRIMARY KEY, UNIQUE, FOREIGN KEY, CONNECTION 제약 조건, CHECK 제약 조건이나 DEFAULT 정의의 속성을 지정합니다. 참고 CONNECTION 제약 조건은 에지 테이블 형식에만 적용됩니다. ...
add constraint ak_employeeSSN unique(ssn) 6:check约束 check不局限于一个特定的列,可以约束一个列,也可以通过某个列来约束另一个列 定义check约束使用的规则与where子句中的基本一样 下面我写几个 between 1 and 12 like '[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9][0-9]' ...
To define a CHECK constraint on a column To replace a stored procedure Use an inline function as a filter predicate for a security policy The integration of .NET Framework CLR into SQL Server is discussed in this article. CLR integration doesn't apply to Azure SQL Database. For Azure Synaps...