存储过程与函数 MySQL 从 5.0 版本开始支持存储过程和函数。存储过程和函数能够将复杂的 SQL 逻辑封装在一起,应用程序无须关注存储过程和函数内部复杂的 SQL 逻辑,而只需要简单地调用存储过程和函数即可。 存储过程概述 含义:存储过程的英文是 Stored Procedure 。它的思想很简单,就是一组经过预先
truncate和delete只删除数据不删除表的结构(定义);drop语句将删除表的结构被依赖的约束(constrain),触发器(trigger),索引(index);依赖于该表的存储过程/函数将保留,但是变为invalid状态; delete语句是DML语句,这个操作会放到rollback segement中,事务提交之后才生效,如果有相应的trigger,执行的时候将被触发;truncate,dro...
Re: Server crashes after trigger execution 959 Peter Brawley 10/23/2020 09:50AM How I can make the trigger calculates the sum of a column for specific condition 3,591 Robin vanpersie 10/03/2020 10:25PM Re: How I can make the trigger calculates the sum of a column for specific conditi...
In this type of UPDATE, the new value for the column to be updated is fetched by a SELECT statement in a subquery. So, let’s take an example here from our “employees” table. Here is our target record that we want to update. In this case, we will update the department number i....
InnoDB data dictionary is not updated while renaming the column. (Bug #19465984) FTS crash after renaming table to different database. (Bug #16834860) Failed preparing of trigger on truncated tables cause error 1054. (Bug #18596756) Metadata changes might cause problems with trigger execution. ...
I am new to mySQL triggers. I have a simple table (id, name, content columns) with an insert and update trigger that should handle the 'content'column. When I issue an update command that does not involve the column handled bu the trigger, it still does its action. What is the prope...
Incompatible Change: Within trigger bodies, INSERT or UPDATE statements containing a SET clause that used OLD or NEW values as assignment targets could raise an assertion or lead to a server exit. Such assignments are no longer permitted. (Bug #32803211) Performance: Internal functions used to co...
消息:在%strigger中,不允许更新%s行。 ·错误:1363 SQLSTATE: HY000 (ER_TRG_NO_SUCH_ROW_IN_TRG) 消息:在%s触发程序中没有%s行。 ·错误:1364 SQLSTATE: HY000 (ER_NO_DEFAULT_FOR_FIELD) 消息:字段'%s'没有默认值。 ·错误:1365 SQLSTATE: 22012 (ER_DIVISION_BY_ZERO) ...
settings of the top-level statement.How to repeat:create table t1 (id int not null); create table t2 (id int not null); insert t1 values (1),(2),(3); update t1 set id=null; create trigger t1_bu before update on t1 for each row insert into t2 values (3); update t1 set id...
It is possible to implement other semantics using triggers. Additionally, MySQL requires that the referenced columns be indexed for performance. However, InnoDB does not enforce any requirement that the referenced columns be declared UNIQUE or NOT NULL. The handling of foreign key references to ...