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...
SQL中的CASE WHEN使用 Case具有两种格式。简单Case函数和Case搜索函数。...简单Case函数的写法相对比较简洁,但是和Case搜索函数相比,功能方面会有些限制,比如写判断式。还有一个需要注意的问题,Case函数只返回第一个符合条件的值,剩下的Case部分将会被自动忽略。...语
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。 这段sql会进行判断每行数据的State字段。最后查询结果会多一个State1字段,State1字段的值就在case when判断里赋值的, 这样程序上再获取到一个数据源之后,就直接取出State1字段值,就完全了上述代码...
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 ...
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 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 Lan...
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 Lan...