UPDATE is an INSERT, UPDATE, DELETE, or MERGE operation that may have input parameters and that returns an integer (number of affected rows).
更新是一个INSERT、UPDATE、DELETE或MERGE操作,可以有输入参数,返回一个整数(受影响的行数)。
When a specified SQL operation — a DELETE, INSERT, or UPDATE — occurs on a table, a trigger can be activated that defines a set of actions.
当一个指定的SQL操作(如DELETE, INSERT,或者是UPDATE操作)作用于某张表时,一个定义了一组操作的触发器就可以被激活。
Since those triggered actions are typically one or more insert, UPDATE, or DELETE statements, the overhead of triggers can be substantial in a mass insert operation.
由于那些被触发的动作通常是一条或多条insert、UPDATE或delete语句,因此,在数据量很大的insert中,触发器的开销会很大。
应用推荐