DROP TABLE IF EXISTS user_profile; CREATE TABLE user_profile( id int , device_id int, gender varchar(10), age int unsigned, university varchar(10), province varchar(10) ); INSERT INTO user_profile (id,device_id,gender,age,university,province) VALUES(1,2138,'male',21,'北京大学','Beijin...
在这个命令里,你至少要为新表声明一个名字,还有各列的名字以及其数据类型。...如果你不再需要一个表,那么可以用DROP TABLE命令删除它。...像这样: DROP TABLE my_first_table;DROP TABLE products; 试图删除一个不存在的表是一个错误。...当然你还可以使用DROP TABLE IF EXISTS来避免错误消息,不过这并不...
语法:删表DROPTABLE SyntaxDROP[TEMPORARY] TABLE [IF EXISTS] tbl_name [, tbl_name] ... [RESTRICT | CASCADE]可一次删除一张或多张表。需具有所删除表上的DROP权限。表定义文件和数据文件均被移除。表被删除后表上的用户权限不会被自己主动删除。參数里表中指定的表名不存在则报错,但对于存在的表仍会删...
DROP[SETTINGS]PROFILE[IFEXISTS]name[,...][ONCLUSTER cluster_name][FROMaccess_storage_type] DROP VIEW Deletes a view. Views can be deleted by aDROP TABLEcommand as well butDROP VIEWchecks that[db.]nameis a view. Syntax: DROPVIEW[IFEXISTS][db.]name[ONCLUSTER cluster][SYNC] ...
$table->addKeyInfo('reminder_pk', XMLDB_KEY_PRIMARY,array('user'));if(!create_table($table)) {thrownewSQLException($table ." could not be created, check log for errors."); } execute_sql('ALTER TABLE {artefact_calendar_calendar} DROP COLUMN {reminder_status}'); ...
参数说明 name 要删除的队列的名称(可能是 schema 限定的)。 IFEXISTS 包含IF EXISTS 子句可指示服务器在队列不存在时不返回错误。服务器会发出通知。 示例 以下示例会删除名为 work_order 的队列: DROP QUEUE work_order; 上一篇:DROP PROFILE下一篇:DROP QUEUE TABLE ...
=> CREATE USER user2; CREATE USER => DROP USER IF EXISTS user2; DROP USER 当用户创建的对象仍然存在时,DROP USER 将失败: => DROP USER IF EXISTS user1; NOTICE: Table T_tbd1 depends on User user1 ROLLBACK: DROP failed due to dependencies DETAIL: Cannot drop User user1 because other ...
if exists ..drop table on linked server. IF Exists Then Drop Job If I stop a Microsoft SQL query before completion could any rows be affected? IF NOT EXIST and IF EXISTS question IF NOT EXISTS and CREATE SCHEMA if nvarchar(50) actual size is 100 then what should i state in .NET SQL...
DROP TABLE IF EXISTS [HumanResource].[Department] END Another benefit of DIE clause it can easily jam with ALTER Statement. Here is quick example ALTER TABLE DIE_TESTING DROP CONSTRAINT IF EXISTS DIE_ID_PK1; ALTER TABLE DIE_TESTING DROP COLUMN IF EXISTS DIE_NAME; ...
DROP PROFILE-- drop a user-defined profile. Synopsis → Wrap DROP PROFILE [IF EXISTS] <profile_name> [CASCADE | RESTRICT]; Description Include theIF EXISTSclause to instruct the server to not throw an error if the specified profile does not exist. The server will issue a notice if the pr...