Fixes an issue in which AFTER DELETE triggers occur in the wrong order in the ON DELETE CASCADE action chain in SQL Server 2014 or 2016.
对于3,需要使用on delete cascade建立外键约束。实验: alter table emp_test add constraint fk_emp_dept_test foreign key(dept) references dept_test(deptno) on delete cascade; delete from dept_test where deptno = 1; 1 row deleted. SQL> select * from dept_test; DEPTNO DEPTNAME --- --- 2 ...
altertable成绩表addconstraint FK_StudentNo foreign key(StudentNo)references Student(StudentNo) ONUPDATECASCADEONDELETECASCADE 级联更新,级联删除,这样在删除主表Student时,成绩表中该学生的所有成绩都会删除。 --检查约束: altertable表名 addconstraintCK_字段名 check(条件表达式)--条件表达式中的条件用关系运算符...
在关系型数据库中,外键约束是用来维护表之间关系的一种机制。当一个表的外键关联的主表中的数据发生变化时,外键约束可以自动更新或删除相关的数据,以保持数据的一致性。ON DELETE CASCADE是一种...
[Id]) ON DELETE CASCADE); CREATE TABLE [Term] ( [Id] int NOT NULL IDENTITY, [Name] nvarchar(max) NOT NULL, [FirstDay] date NOT NULL, [LastDay] date NOT NULL, [SchoolId] int NOT NULL, CONSTRAINT [PK_Term] PRIMARY KEY ([Id]), CONSTRAINT [FK_Term_Schools_SchoolId] FOREIGN KEY...
For more information, see Create an ApsaraDB RDS for SQL Server instance. Usage notes Note DTS does not migrate foreign keys from the source to the destination database. As a result, operations like cascade and delete in the source database are...
1. 删除 ?删除(On Delete):删除记录之前触发这个事件。 ? 打开(On Open):窗体被打开,但还未显示出来时 触发这个事件。 wenku.baidu.com|基于19个网页 2. 表中删除行 SET DEFAULT 意味着,当您在被引用的表中删除行(ON DELETE) 或更新被引用的键 (ON UPDATE) 时,SQL Server 会将引 … ...
[PRIMARY] GO ALTER TABLE [dbo].[ADDRESS_QUEUE] WITH CHECK ADD CONSTRAINT [FK_ADDRESS_QUEUE_VEHICLE_HISTORY] FOREIGN KEY([HISTORY_ID]) REFERENCES [dbo].[VEHICLE_HISTORY] ([HISTORY_ID]) ...
on update cascade # 同步更新 on delete cascade # 同步删除 ); insert into dep(dep_name,dep_desc) values('sb教学部','教书育人'),('外交部','多人外交'),('nb技术部','技术能力有限部门'); insert into emp(name,dep_id) values('jason',2),('egon',1),('tank',1),('kevin',3); ...
(SQL on OBS or Hadoop) CREATE FOREIGN TABLE (for OBS Import and Export) CREATE FOREIGN TABLE (SQL on other GaussDB(DWS)) CREATE FUNCTION CREATE GROUP CREATE INDEX CREATE REDACTION POLICY CREATE ROW LEVEL SECURITY POLICY CREATE PROCEDURE CREATE RESOURCE POOL CREATE ROLE CREATE SCHEMA CREATE ...