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...
SQL进阶第一章---CASE表达式之CHECK约束 & 使用CASE表达式在Update语句里面进行条件分支 用CHECK约束定义多个列的条件关系 假设某个公司规定“女性员工的工资必须是在20万日元以下”,不得不说句这个规定真是太TM不合理了,在这个公司的人事表中,这条物理的规定是使用CHECK约束来描述的。 CONSTRAINTcheck_salaryCHECK(CA...
Alter table dept50 add constraint dept50_fk foreign key(d_id) references dept60(id); 1. 2. 3. 4. 5. 六、定义check约束 创建表时定义check约束 例 创建dept30表,包括ID、薪水,薪水不能小于1000,并自定义名字; Create table dept30(id number , salary number(8,2) , constraint dept30_ck ...
例如<Table 'Sample.MyTable', Constraint 'MYTABLE_UNIQUE3', Field(s) FullName="Molly Bloom"; failed unique check> or <Table 'Sample.MyTable', Constraint 'MYTABLE_PKEY2', Field(s) FullName="Molly Bloom"; failed unique check>。 如果更新指定的值不在其VALUELIST参数中列出,则不能更新字段值...
SQL 复制 USE AdventureWorks2022; GO BEGIN TRANSACTION; BEGIN TRY -- Intentionally generate a constraint violation error. UPDATE HumanResources.Department SET Name = N'MyNewName' WHERE DepartmentID BETWEEN 1 AND 2; END TRY BEGIN CATCH SELECT ERROR_NUMBER() AS ErrorNumber ,ERROR_SEVERITY() AS...
SQLCODE - 120% msg字符串包括违背唯一性约束的字段和值。 例如<Table 'Sample.MyTable', Constraint 'MYTABLE_UNIQUE3', Field(s) FullName="Molly Bloom"; failed unique check> or <Table 'Sample.MyTable', Constraint 'MYTABLE_PKEY2', Field(s) FullName="Molly Bloom"; failed unique check>。
procsql;createtablework.employees /*将限制条件直接跟在变量后*/(IDchar(5)primarykey, Namechar(10), Genderchar(1)notnullcheck(genderin('M','F')), HDate date label='Hire Date'); Creating a Constraint by Using a Constraint Specification ...
Check constraints:If the identified table (or base table of the identified view) has any check constraints, each check constraint must be true or unknown for each row that is updated in the table. All checks constraints are effectively validated at the end of the statement. In the case of ...
ClassMethodInsertOrUpdate(){&sql(CREATETABLESQLUser.CaveDwellers(NumINTUNIQUE,CaveClusterCHAR(80)NOTNULL,TroglodyteCHAR(50)NOTNULL,CONSTRAINTCaveDwellerPKPRIMARYKEY(Num)))ifSQLCODE=0{w!,"表创建"}elseifSQLCODE=-201{w!,"表已经存在"}else{w!,"SQL表创建错误代码: ",SQLCODEq}} ...
If any column that is part of a unique constraint is updated, SQL Server implements the update as a "deferred update", which means as a pair of DELETE/INSERT operations. This "deferred update" causes replication to send a pair of DELETE/INSERT statements to the subscribers. There ...