CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING. --Syntax for SQL Server and Azure SQL DatabaseSimple...
Simple Case Statement CASE [input_expression] WHEN when_expression THEN when_true_result_expression [...n] [ELSE else_result_expression] END Search Case Statement CASE WHEN Boolean_expression THEN when_true_result_expression [...n] [ELSE else_result_expression] END ...
CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING. --Syntax for SQL Server and Azure SQL DatabaseSimple...
Case语句语法(MySQL):- WHEN search_condition THEN statement_listEND CASESimple CASE expression: 浏览3提问于2014-01-17得票数 0 回答已采纳 2回答 SQL Server Case语句 、、、 我正在尝试运行这条sql语句,但它生成了错误“update附近的语法不正确” When 'MediaFiles' Then update 浏览1提问于2011-12-19...
这段代码是完全ok的。是没什么问题。但是我们来进行一下优化,但是我们并不是从代码进行优化。我们从sql语句开始。 这里是获取某个字段值。然后进行一系列的判断,给变量赋值,我们完全可以在sql语句中使用case when语句来进来判断; 从而提高程序可读性和性能。
SQL Server allows for only 10 levels of nesting in CASE expressions.The CASE expression can't be used to control the flow of execution of Transact-SQL statements, statement blocks, user-defined functions, and stored procedures. For a list of control-of-flow methods, see Control-of-Flow ...
CASE WHEN expression THEN statement [ELSE statement] END 首先,在 case when 结构中,必须要置入一个判断表达式,这个 表达式可以是比较、运算或者逻辑表达式,也可以是一个嵌套的 case when 子结构,它的作用是根据判断表达式的值,选择执行哪一个表达 式。 以"成绩优秀" 为判断条件,case when 语句可以写成这样: ...
Assume that you execute a Transact-SQL query in Microsoft SQL Server 2012. When the query contains a long case statement, the query fails. Additionally, you receive the following error: Msg 8631, Level 17, State 1, Line ...
SQL USEAdventureWorks2022; GOSELECTProductNumber,Category=CASEProductLineWHEN'R'THEN'Road'WHEN'M'THEN'Mountain'WHEN'T'THEN'Touring'WHEN'S'THEN'Other sale items'ELSE'Not for sale'END,NameFROMProduction.ProductORDERBYProductNumber; GO B. Use a SELECT statement with a searched CASE expression ...
SQL Server allows for only 10 levels of nesting in CASE expressions.The CASE expression can't be used to control the flow of execution of Transact-SQL statements, statement blocks, user-defined functions, and stored procedures. For a list of control-of-flow methods, see Control-of-Flow ...