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: DROP TABLE IF EXISTSWORKLIB....
2. 使用DROP TABLE IF EXISTS语句 MySQL提供了DROP TABLE IF EXISTS语句,该语句在删除表之前会自动检查表是否存在。如果表存在,则删除它;如果表不存在,则不执行任何操作,也不会报错。以下是一个示例: sql DROP TABLE IF EXISTS your_table; 这条语句非常简洁且有效,是处理表删除操作的推荐方式。 3. 完整示例...
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 raise error if field SOME_FIELD is not exist or execute statement 'DROP INDEX IDX1 [IF E...
I don't like these, and if you also don't like them, then you might try new DROP IF EXISTS (a.k.a. DIE :) ) statements in SQL Server 2016.From SQL Server 2016 CTP3 you can use new DIE statements instead of big IF wrappers, e.g.:...
I am trying to drop a column from a table. How can I check if the column exists or not? I went through the documentation athttps://www.postgresql.org/docs/9.2/static/sql-altertable.html, but didn't find any example how to do it. ...
BEGIN EXECUTE IMMEDIATE 'DROPTABLE XX'; EXCEPTION WHEN OTHERS THEN IF SQLCODE != -942 THEN RAISE; END IF; END; / COMMIT; sql 转载 mob60475700e001 2020-05-07 10:03:00 254阅读 2 mysqlnotexist # 如何实现"mysqlnotexist" ## 甘特图 ```mermaid gantt dateFormat YYYY-MM-DD title 实现"mysq...
如果不指定IF EXISTS,当目标表不存在时,系统会返回ERROR: table "non_exist_table" does not exist报错。 table_name 需要删除的表名称。 示例 删除表的示例语句如下。 DROP TABLE holo_test; HoloWeb可视化删除表 HoloWeb提供可视化删除表功能,无需写SQL命令就能删除表,步骤如下。 进入HoloWeb页面,详情请参见连接...
如果不指定IF EXISTS,当目标表不存在时,系统会返回ERROR: table "non_exist_table" does not exist报错。 table_name 需要删除的表名称。 示例 删除表的示例语句如下。 DROP TABLE holo_test; HoloWeb可视化删除表 HoloWeb提供可视化删除表功能,无需写SQL命令就能删除表,步骤如下。 进入HoloWeb页面,详情请参见连接...
TheDROP DATABASE IF EXISTS,DROP TABLE IF EXISTS, andDROP VIEW IF EXISTSstatements are always replicated, even if the database, table, or view to be dropped does not exist on the source. This is to ensure that the object to be dropped no longer exists on either the source or the replic...
从 SQL Server 2016 (13.x)开始,可以使用语法 DROP INDEX IF EXISTS。适用于:SQL Server 2008 (10.0.x) 及更高版本。SQL 复制 --Create a clustered index on the PRIMARY filegroup if the index does not exist. CREATE UNIQUE CLUSTERED INDEX AK_BillOfMaterials_ProductAssemblyID_ComponentID_StartDate...