SQL Server 有各种强制执行实体完整性的机制,包括索引、唯一约束、主键约束和触发器。 写在前面 参考官方文档https://support.microsoft.com/zh-cn/help/139444/how-to-remove-duplicate-rows-from-a-table-in-sql-serverlink 原文摘录 需要检查是否是除了id列之外的整行重复,请对比
Query OK,0rows affected (0.01sec) mysql>mysql>DROPTABLEIFEXISTSB3; #删除一张表,我这里加了判断条件,意思是当这张表存在就删除,若不存在就不执行删除操作,这样可以避免报错～ Query OK,0rows affected,1warning (0.00sec) mysql>mysql>SHOW TABLES;+---+|Tables_in_A3|+---+|v_B3|+---+1rowinset...
Applies to: SQL Server 2008 (10.0.x) and later versions. SQL Database supports "default" as the filegroup name. Specifies a location to move the data rows that currently are in the leaf level of the clustered index. The data is moved to the new location in the form of a heap. You ...
mysql>create user'testuser01'@'%'identified by'Test01.~!#';QueryOK,0rowsaffected(0.01sec)# 删除用户testuser01 mysql>drop user'testuser01'@'%';QueryOK,0rowsaffected(0.01sec)# 再次创建testuser01成功 mysql>create user'testuser01'@'%'identified by'Test01.~!#';QueryOK,0rowsaffected(0.01s...
(0.01sec)mysql>SETGLOBALinnodb_adaptive_hash_index=OFF;QueryOK,0rowsaffected(0.00sec)mysql>SHOWGLOBALVARIABLESLIKE'innodb_adaptive_hash_index';+---+---+|Variable_name|Value|+---+---+|innodb_adaptive_hash_index|OFF|+---+---+1rowinset(0.01sec) 2、删除对应的磁盘数据文件ibd 在删除数据文件...
(3) unsigned | NO | | NULL | | | alexa | int(10) unsigned | NO | | NULL | | | uv | float | YES | | 0 | | | country | char(3) | NO | | | | +---+---+---+---+---+---+ 7 rows in set (0.00 sec) 这意味着 website 表是有效的,接着我们使用如下的代码将它...
If you wanted to process the rows displayed by a SELECT statement within a stored procedure, then you would need to store the result set rows in some other SQL Server table or object. Next, process the results in that object. Drop or Delete a SQL Server Stored Procedure ...
sp_droppullsubscriptiondeletes the corresponding row in theMSreplication_subscriptionstable and the corresponding Distributor Agent at the Subscriber. If no rows are left inMSreplication_subscriptions, it drops the table. Examples SQL -- This script uses sqlcmd scripting variables. They are in...
5Retention periodMetadata that controls how long rows in the database mirroring status table are preserved. Note This procedure drops warning thresholds, regardless of whether they were specified usingsp_dbmmonitorchangealertor Database Mirroring Monitor. ...
删除数据库的基本SQL语法格式为: DROPDATABASE database_name;//删除一个名为 database_name 的数据库 “database_name”为要删除的数据库的名称。若指定的数据库不存在,则删除出错。 mysql> DROP DATABASE database_name; Query OK, 0 rows affected (0.00 sec) ...