The solution is to add conditional logic to your T-SQL to check if the specified table exists before trying to drop the table. If it exists, you drop the table, if it doesn’t exist you can skip the DROP TABLE.
3.4、PostgreSQL 中,ALTER TABLE命令用于添加,修改,删除一张已经存在表的列。 3.4.1、用 ALTER TABLE 在一张已存在的表上添加列的语法如下: ALTER TABLE table_name ADD column_name datatype; 3.4.2、在一张已存在的表上 DROP COLUMN(删除列),语法如下: ALTER TABLE table_name DROP COLUMN column_name; 3...
DROP TABLE IF EXISTS <Temp-Table-Name> Example 1 2 DROPTABLEIF EXISTS #TempTab GO In SQL Server 2014 And Lower Versions Older versions of SQL Server does not have DIY or DROP IF EXISTS functionality. So, we have to use the old technique of checking for the object using OBJECT_ID. Let...
create table#temp(FIDintidentity(1,1),ReferenceIDvarchar(20))insert into#temp(ReferenceID)select top100000ReferenceID from chineseresume order by updatedate select*from #temp where Fid>40and fid<=60drop table #temp end SQL Server优化的方法<二> 一个系统的性能的提高,不单单是试运行或者...
DROP TABLE--删除一个表 DROP TRIGGER--删除一个触发器定义. DROP TYPE--删除一个用户定义数据类型 DROP USER--删除一个数据库用户帐号 DROP VIEW--删除一个视图 END--提交当前的事务 EXPLAIN--显示语句执行规划 FETCH--用游标从表中抓取行 GRANT--定义访问权限 ...
PRINT ' '; PRINT '--- Next, memory-optimized, faster. ---';DROPTYPEIFEXISTSdbo.typeTableC_mem; GOCREATETYPEdbo.typeTableC_mem-- !! Memory-optimized.ASTABLE( Column1INTNOTNULLINDEXix1, Column2CHAR(10) )WITH(MEMORY_OPTIMIZED =ON); GODECLARE@dateString_...
PRINT ' '; PRINT '--- Next, memory-optimized, faster. ---';DROPTYPEIFEXISTSdbo.typeTableC_mem; GOCREATETYPEdbo.typeTableC_mem-- !! Memory-optimized.ASTABLE( Column1INTNOTNULLINDEXix1, Column2CHAR(10) )WITH(MEMORY_OPTIMIZED =ON); GODECLARE@dateString_Begi...
C. Scenario: Replace session temp table D. Scenario: Table variable can be MEMORY_OPTIMIZED=ON Show 4 more Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance If you use temporary tables, table variables, or table-valued parameters, consider conversions of them to use memory...
DROP TABLE IF EXISTS reason_t1; CREATE TABLE reason_t1 ( TABLE_SK INTEGER , TABLE_ID VARCHAR(20) , TABLE_NA VARCHAR(20) ); 向表中插入一条记录: INSERT INTO reason_t1(TABLE_SK, TABLE_ID, TABLE_NA) VALUES (1, 'S01', 'StudentA'); 向表中插入一条记录,和上一条语法等效: INSERT...
history_table_name [, DATA_CONSISTENCY_CHECK = { ON | OFF } ] ) ] } Arguments database_name The name of the database in which the table is created. database_name must specify the name of an existing database. If not specified, database_name defaults to the current database. The...