3. 如果CTE的表达式名称与某个数据表或视图重名,则紧跟在该CTE后面的SQL语句使用的仍然是CTE,当然,后面的SQL语句使用的就是数据表或视图了,如下面的SQL语句所示: -- table1是一个实际存在的表 with table1 as ( select * from persons where age < 30 ) select * from table1 -- 使用了名为table1的公...
Transact-SQL syntax conventionsSyntaxsyntaxsql העתק [ WITH <common_table_expression> [ ,...n ] ] <common_table_expression>::= expression_name [ ( column_name [ ,...n ] ) ] AS ( CTE_query_definition
YouTube – SQL WITH Clause | How to write SQL Queries using WITH Clause | SQL CTE (Common Table Expression) 特色 1. CTE 可以引用自身, 实现递归查询. (Oracle 用 connect by prior) 2. 它有点像表变量, 其后的 query 都可以引用它. 然后自动销毁. 很方便 3. 可读性很棒 复用与可读性优化 来看...
n ] ] <common_table_expression>::= expression_name [ ( column_name [ ,...n ] ) ] AS ( CTE_query_definition ) 参数 expression_name 是公用表表达式的有效标识符。 expression_name 须不同于在同一 WITH <common_table_expression> 子句中定义的任何其他公用表表达式的名称,但可以与基表或基视图的...
关于SQL中CTE(公用表表达式)(Common-Table-Expression)的总结
For more information about common table expressions, see WITH common_table_expression (Transact-SQL). Anteckning During preview, creation of nested CTE is supported by SQL Server Management Studio (SSMS) only. Intellisense in SSMS doesn't recognize nested CTE syntax but this doesn't block creati...
更多使用详细介绍与使用可参考:https://docs.microsoft.com/zh-cn/sql/t-sql/queries/with-common-table-expression-transact-sql?view=sql-server-ver15 一路走来数个年头,感谢RDIFramework.NET框架的支持者与使用者,大家可以通过下面的地址了解详情。
Common Table Expression (CTE) is a temporary named result set that simplifies SQL queries. MaxCompute supports the standard SQL CTE, enhancing the readability and execution efficiency of SQL statements. This topic describes the features, command syntax, and usage examples of CTE. Features CTE serves...
<common_table_expression>::= expression_name [ ( column_name [ ,n ] ) ]AS ( CTE_query_definition )现在使⽤CTE来解决上⾯的问题，SQL语句如下：复制代码代码如下:with cr as (select CountryRegionCode from person.CountryRegion where Name like 'C%')select * from person.StateProvince where ...
SQL Server 中的公用表表达式(Common Table Expressions,简称 CTE)是一种临时命名的结果集,它在执行查询时存在,并且只在该查询执行期间有效。CTE 类似于一个临时的视图或者一个内嵌的查询,但它提供了更好的可读性和重用性。 CTE 使用 WITH 子句来定义,后面紧跟着一个或多个 CTE 的名称和定义(即 SELECT 语句...