触发器是由某个事件来触发某个操作.这些事件包括INSERT语句,UPDATE语句和DELETE语句.当数据库执行这些事件时,就会激活出发器的相应操作.创建触发器在MySQL中创建触发器通过SQL语句CREATE TRIGGER来实现,其语法形式如下:CREATE trigger trigger_name BEFORE|AFTER trigger_EVENT ON TABLE_NAME FOR EA ...
2)变量声明、赋值与引用 3)函数与操作符 字符串 日期 空值判断与处理 转换 语句 4)游标 5)触发器 6)过程 7)数据字典/系统表 8)SQL 9)全局变量 10)命令行查询工具 ISQL SQL PLUS 读取、执行SQL文件 Isql –Usa –Ppass –Shost –ifile sqlplus [-s] user/pass@db -@filename 11)杂项 1. select...
INSERT INTO [HumanResources].[EmployeePayHistory] ([EmployeeID] ,[RateChangeDate] ,[Rate] ,[PayFrequency]) VALUES (@EmployeeID, @RateChangeDate, @Rate, @PayFrequency); COMMIT TRANSACTION; END TRY BEGIN CATCH -- Rollback any active or uncommittable transactions before -- inserting information...
DBCC NULLIF TRIGGER DEALLOCATE OF TRUNCATE DECLARE OFF TRY_CONVERT DEFAULT OFFSETS TSEQUAL 刪除 開啟 UNION 拒絕 OPEN UNIQUE DESC OPENDATASOURCE UNPIVOT DISK OPENQUERY UPDATE DISTINCT OPENROWSET UPDATETEXT DISTRIBUTED OPENXML USE DOUBLE OPTION USER DROP 或者 VALUES DUMP ...
CREATE TRIGGER IF FIELD IS EMPTY DO NOT INSERT create trigger on northwind datase .. please help create TRIGGER remove white spaces from a fields in table-scan and fix Create Trigger to delete old data first before Inserts. create view as EXEC sp Create view dynamic pivot create view from ...
Before SQL/PSM was introduced in SQL:1999, the ANSI standard didn’t include flow control constructs. Therefore, there are significant syntax differences among RDBMS engines. SQL Server provides the following flow control keywords. BEGIN… END— Define boundaries f...
Do not start a transaction and ensure the session setting IMPLICIT_TRANSACTIONS is OFF before executing the CREATE or DROP statement. Feature DDL triggers Memory-optimized tables and natively compiled stored procedures cannot be created or dropped if there is a server or database trigger for that ...
-- Trigger on an INSERT, UPDATE, or DELETE statement to a table or view (DML Trigger) DROP TRIGGER [ IF EXISTS ] [schema_name.]trigger_name [ ,...n ] [ ; ] -- Trigger on a CREATE, ALTER, DROP, GRANT, DENY, REVOKE or UPDATE statement (DDL Trigger) DROP TRIGGER [ IF EXISTS ...
Do not start a transaction and ensure the session setting IMPLICIT_TRANSACTIONS is OFF before executing the CREATE or DROP statement. Feature DDL triggers Memory-optimized tables and natively compiled stored procedures cannot be created or dropped if there is a server or database trigger for that ...
If you are adding this pattern to existing triggers such as “AFTER INSERT, UPDATE, DELETE”, then make sure to check that the execution of this trigger was based on an update. This can be done by checking if there are any records in the Inserted and deleted tables that are used in ...