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...
Note:TheCHECKconstraint is used to validate data while insertion only. To check if the row exists or not, visitSQL EXISTS. Example 1: SQL CHECK Constraint Success -- apply the CHECK constraint to the amount columnCREATETABLEOrders ( order_idINTPRIMARYKEY, amountINTCHECK(amount >0) );-- am...
SQL CHECK on CREATE TABLE The following SQL creates aCHECKconstraint on the "Age" column when the "Persons" table is created. TheCHECKconstraint ensures that the age of a person must be 18, or older: MySQL: CREATETABLEPersons ( ID intNOTNULL, ...
A check constraint can be defined in either aSQL CREATE TABLE statementor aSQL ALTER TABLE statement. Using a CREATE TABLE statement The syntax for creating a check constraint using a CREATE TABLE statement in Oracle is: CREATE TABLE table_name ( column1 datatype null/not null, column2 data...
使用Transact-SQL 为INSERT 和 UPDATE 语句禁用 CHECK 约束 在“对象资源管理器”中,连接到 数据库引擎的实例。 在标准菜单栏上,单击“新建查询”。 将以下示例复制并粘贴到查询窗口中,然后单击“执行”。 SQL USEAdventureWorks2022; GOALTERTABLEPurchasing.PurchaseOrderHeaderNO...
SELECT table_name, constraint_type, constraint_name FROM information_schema.table_constraints WHERE table_name='CUSTOMERS'; OutputThe above query will show all the details of the CUSTOMERS table, including how many columns have check constraints and what constraints we have specified in the table ...
SQL Server Azure SQL 数据库 Azure SQL 托管实例 检查当前数据库中指定表上的指定约束或所有约束的完整性。 Transact-SQL 语法约定 语法 syntaxsql DBCCCHECKCONSTRAINTS[ (table_name|table_id|constraint_name|constraint_id) ] [WITH[ {ALL_CONSTRAINTS|ALL_ERRORMSGS} ] [ , ] [NO_INFOMSGS] ] ...
IF OBJECT_ID ('dbo.Vendors', 'U') IS NOT NULL DROP TABLE dbo.Vendors; GO CREATE TABLE dbo.Vendors (VendorID int PRIMARY KEY, VendorName nvarchar (50), CreditRating tinyint) GO ALTER TABLE dbo.Vendors ADD CONSTRAINT CK_Vendor_CreditRating CHECK (CreditRating >= 1 AND CreditRating <= ...
Getting an error with following sql query with mysql v8 which was working with v5.7. Create table test ( empId char(36) not null, tolerance decimal(5,2) not null check (pct > 0 and pct <= 100), primary key (empId) ); ERROR 3813 (HY000): Column check constraint 'test_chk_1' re...
A check constraint can NOT include a Subquery. A check constraint can be defined in either a CREATE TABLE statement or a ALTER TABLE statement.Using a CREATE TABLE statement The syntax for creating a check constraint using a CREATE TABLE statement in SQL Server (Transact-SQL) is: CREATE TABLE...