begin select count(*) into c from user_tables where table_name = upper('continent'); if c = 1 then execute immediate 'drop table continent'; end if; end; 这两个脚本都运行良好,但我的老板想要IF EXIT类的东西。任何人都可以帮助我。在这种情况下如何使用 IF EXIT ?
IF OBJECT_ID('your_schema.your_table_name', 'U') IS NOT NULL BEGIN DROP TABLE your_schema.your_table_name; END ELSE BEGIN PRINT 'Table does not exist'; END 注意事项 在执行这些脚本之前,请确保将your_table_name替换为你想要删除的表的名称。 在某些情况下,你可能还需要指定表的模式(schema)...
drop database [数据库名] 2 判断表是否存在 Sql代码 if exists (select * from sysobjects where id = object_id(N’[表名]’) and OBJECTPROPERTY(id, N’IsUserTable’) = 1) drop table [表名] if exists (select * from sysobjects where id = object_id(N’[表名]’) and OBJECTPROPERTY(id...
If a table does not exist, dropping it will throw an error. To fix this issue, we can add the optionalIF EXISTScommand while dropping a table. For example, -- delete Orders table if it existsDROPTABLEIFEXISTSOrders; Run Code Here, the SQL command will only drop a table if there exist...
DROPTABLEIFEXISTS`student`; CREATETABLE`student` ( `stuid`varchar(16)NOTNULLCOMMENT'学号', `stunm`varchar(20)NOTNULLCOMMENT'学生姓名', PRIMARYKEY (`stuid`) )ENGINE=InnoDBDEFAULTCHARSET=utf8; -- --- -- Records of student -- --- INSERT...
IF COL_LENGTH( '表名','列名') IS NULL PRINT 'not exists' ELSE PRINT 'exists' alter table 表名drop constraint 默认值名称 go alter table 表名drop column 列名 go --- --判断要创建临时表是否存在 If Object_Id('Tempdb.dbo.#Test') Is Not Null Begin print '存在' End Else Begin...
DROP TABLE DROP DATABASE DROP VIEW DROP FUNCTION 1、DROP CATALOG DROPCATALOG[IFEXISTS]catalog_name 1. 删除给定名字的 catalog。 IF EXISTS 如果目标 catalog 不存在,则不会执行任何操作。 2、DROP DATABASE DROPDATABASE[IFEXISTS][catalog_name.]db_name[(RESTRICT|CASCADE)] ...
2. Why Should We Check if a Table Exists Before Dropping It? The DROP TABLE clause deletes a table and all its data from the database in SQL. However, this commandthrows an error when the table doesn’t exist in the database used,disrupting the flow of the SQL script or application....
Submitted by: eXandr (i.reg) Votes: 4 It should be possible to determine not cause an error when deleting an object that does not exist Something like that: execute statement 'ALTER TABLE SOME_TABLE DROP [IF EXISTS] SOME_FIELD'; -- no ra...
DROP IF EXISTS Each of the DROP statements supports an IF EXISTS clause. This allows the drop of an object to complete successfully, with no error being issued, if the object does not exist. For example, to drop the EMPLOYEE table from WORKLIB, issue the following statement:...