Question

我得到了

＆＃39; =＆＃39;＆＃34;附近的语法不正确对于所有＆＃39; =＆＃39;

在以下案例中：

DECLARE @TipoRegisto    AS VARCHAR(1)
DECLARE @idTipoRegisto  AS INT

SELECT 
       CASE @TipoRegisto            
              WHEN @idTipoRegisto = 0 THEN 'R' 
              WHEN @idTipoRegisto = 1 THEN 'I' 
              WHEN @idTipoRegisto = 2 THEN 'C' 
              ELSE  '' 
       END

有人可以解释原因吗？

Answer 1

您非常接近，Case返回您要将变量设置为

的值

DECLARE @TipoRegisto    AS VARCHAR(1)
DECLARE @idTipoRegisto  AS INT

SELECT @TipoRegisto = CASE
                           WHEN @idTipoRegisto = 0 THEN 'R' 
                           WHEN @idTipoRegisto = 1 THEN 'I' 
                           WHEN @idTipoRegisto = 2 THEN 'C' 
                           ELSE  '' 
                      END

Answer 2

试试这个：

DECLARE @TipoRegisto    AS VARCHAR(1)
DECLARE @idTipoRegisto  AS INT

SET @TipoRegisto = (SELECT 
                           CASE @idTipoRegisto            
                                WHEN 0 THEN 'R' 
                                WHEN 1 THEN 'I' 
                                WHEN 2 THEN 'C' 
                           ELSE  '' 
                     END)

在T-SQL Case表达式中评估变量

2 个答案: