Question

我的逻辑必须有点时髦，因为当我测试以确保这些CASE陈述是真的时，我不会得到预期的结果......

例如，如果Sample1 = 'FI'，Sample2 = 'GOVT'和Sample3 = 'GOVT'，我没有得到'OKFI' ...我知道我必须在某个地方有一些古怪的逻辑......

关于这些事情的最佳实践的任何想法？

CREATE FUNCTION SampleFunction
(
    @Sample1 varchar(50),
  @Sample2 varchar(50) = null,
  @Sample3 varchar(50) = null
)
RETURNS VARCHAR(255)
AS
BEGIN

declare @output varchar(255)



SET @output = 

CASE WHEN @Sample1 = 'CASH' THEN 'CASH' 

WHEN @Sample1 = 'ST' THEN 
    CASE WHEN @Sample2 ='TBILL' THEN
        CASE WHEN @Sample3 = 'TBILL' THEN 'OKFI' 

WHEN @Sample1 = 'FI' THEN
    CASE WHEN @Sample2 = 'GOVT' THEN
        CASE WHEN @Sample3 = 'GOVT' THEN 'OKFI'

WHEN @Sample1 = 'DERV' THEN
    CASE WHEN @Sample2 = 'CURRCONT' THEN 
        CASE WHEN @Sample3 = 'FORWARD' THEN 'CASH'
            WHEN @Sample3 = 'SPOT' THEN 'CASH' 
WHEN @Sample2 = 'SWAP' THEN
    CASE WHEN @Sample3 = 'CURRSWAP' THEN 'CASH'
        WHEN @Sample3 = 'INDXSWAP' THEN 'OTHER'

WHEN @Sample2 = 'FUTURE' THEN
CASE WHEN @Sample3 = 'COMFUT' THEN 'COM'
    WHEN @Sample3 = 'BFUT' THEN 'OKFI'
    WHEN @Sample3 = 'NDXFUT' THEN 'OKSHARES' 
    WHEN @Sample3 = 'EQFUT' THEN 'OKSHARES' 
    WHEN @Sample3 = 'CURRFUT' THEN 'CASH'

WHEN @Sample2 = 'OPTION' THEN
CASE WHEN @Sample3 = 'CUROPTION' THEN 'CASH' END

ELSE 'OTHER' 

END END END
END END END
END END END RETURN @Output

END -- FUNCTION

Answer 1

您应该创建@table变量，甚至是列Sample1, Sample2, Sample3, Output的物理永久表 - 在其中插入所有组合和所需的输出，然后根据您的{{1}从中选择Output }，@Sample1，@Sample2变量。

通过CASE中的几十个CASE，你只会迷路。

这样的事情：

@Sample3

<强> SQLFiddle DEMO

如果您想坚持使用CASE，原始查询的问题就是错误地放置了CREATE FUNCTION SampleFunction2 ( @Sample1 VARCHAR(50) , @Sample2 VARCHAR(50) = NULL , @Sample3 VARCHAR(50) = NULL ) RETURNS VARCHAR(255) AS BEGIN DECLARE @output VARCHAR(255) DECLARE @tempResults TABLE ( Sample1 VARCHAR(50) , Sample2 VARCHAR(50) , Sample3 VARCHAR(50) , [Output] VARCHAR(255) ) INSERT INTO @tempResults VALUES ( 'CASH', NULL, NULL, 'CASH' ) ,( 'ST', 'TBILL', 'TBILL', 'OKFI' ) ,( 'FI', 'GOVT', 'GOVT', 'OKFI' ) ,( 'DERV', 'CURRCONT', 'FORWARD', 'CASH' ) ,( 'DERV', 'CURRCONT', 'SPOT', 'CASH' ) ,( NULL, 'SWAP', 'CURRSWAP', 'CASH' ) ,( NULL, 'SWAP', 'INDXSWAP', 'OTHER' ) ,( NULL, 'FUTURE', 'COMFUT', 'COM' ) ,( NULL, 'FUTURE', 'BFUT', 'OKFI' ) ,( NULL, 'FUTURE', 'NDXFUT', 'OKSHARES' ) ,( NULL, 'FUTURE', 'EQFUT', 'OKSHARES' ) ,( NULL, 'FUTURE', 'CURRFUT', 'CASH' ) ,( NULL, 'OPTION', 'CUROPTION', 'CASH' ) SELECT @output = [Output] FROM @tempResults WHERE (@Sample1 IS NULL OR Sample1 = @Sample1) AND (@Sample2 IS NULL OR Sample2 = @Sample2) AND (@Sample3 IS NULL OR Sample3 = @Sample3) IF @output IS NULL SET @output = 'OTHER' RETURN @output END：

END

<强> SQLFiddle DEMO

在SQL Server 2008中使用嵌套的CASE语句

1 个答案: