使用APPLY UPDATE some_table SET some_row = another_row, some_row2 = another_row/2 FROM some_table st CROSS APPLY (SELECT TOP 1 another_row FROM another_table at WHERE at.shared_id=st.shared_id) WHERE ... Run Code Online (Sandbox Code Playgroud) 在更新语句中使用交叉应用归档...
SQL Server 将PL/SQL查询转换为T-SQL，T-SQL通过select将行的值复制到另一行不幸的是，UPDATE语句在...
SELECT TOP (select count(*) cn from anotherTable where 0 = 0) cols FROM tableName where 0 = 0 ORDER BY col。 还有一点就是在sql server2005中可以在delete或者update中使用top了,不过感觉这个功能不会很常用。
语法:UPDATE 表名称 SET 列名称 = 新值 WHERE 列名称 = 某值 3、DELETE 语句:用于删除表中的行。 语法:DELETE FROM 表名称 WHERE 列名称 = 值 4、SELECT 语句:用于从表中选取数据。 语法:SELECT 列名称 FROM 表名称版权声明:本文为wwwwerewrew原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链...
甚至使用子查询确定要去的条数: SELECT TOP (select count(*) cn from anotherTable where 0 = 0) cols FROM tableName where 0 = 0 ORDER BY col。 还有一点就是在sql server2005中可以在delete或者update中使用top了,不过感觉这个功能不会很常用。
DELETE FROM your_table; 注意:这会逐行删除数据,并记录每行的删除操作,因此可能比 TRUNCATE TABLE 更慢,并且会触发 DELETE 触发器。 插入新数据(与方法一相同)。 方法三:使用带有 ON DUPLICATE KEY UPDATE 的INSERT(适用于MySQL) 如果你的表中定义了唯一键或主键,你可以使用 MySQL 的 ON DUPLICATE KEY UPDATE...
Joins in T-SQL are clauses used to combine rows from two or more tables, based on a related column between them. Joins specify how SQL should use data from one table to select the rows in another table. Several operators -- such as =, <, >, <>, <=, >=, !=, BETWEEN, LIKE,...
如果有两个 WHEN MATCHED 子句,一个必须指定 UPDATE 操作,另一个必须指定 DELETE 操作。 如果在 <merge_matched> 子句中指定了 UPDATE,并且根据 <merge_search_condition> <table_source> 中有多行与 target_table 中的一行匹配, SQL Server 便会返回错误。 MERGE 语句无法多次更新同一行,也无法更新和删除同...
An attribute or set of attributes, that refers to the primary key of another table is known as a foreign key. A foreign key is essentially used to connect two tables. 9. What Subsets of SQL are there? The principal SQL subsets are: ...
Insert Delete Update Update UPDATE <modified_table> SET col1 = <new_value>[, col2 = <new_value>] [FROM <modified_table> <join_type> JOIN <another_table> ON <join_condition>] WHERE <search_condition>] 2.5.Update 2.5.1.The syntax of the UPDATE statement ...