Sql 如何根据动态查询结果的值执行动态查询

我有以下SP，当

query 2的值=0

或
null
时，我想执行
query 3
，并想返回
query 1和query 2/query 3

当我执行SP时，我在
@val1=50
中有一个值，但它仍然在
if循环中，我只想返回
@val
，
@val1
，但我得到了5个值

exec usp_GetDefaultValue 'HQP','home','ConDefault','12345'

结果:

HQP:0//query 1 HQP:50//query 2@val:0@val1:0有人能帮我吗

ALTER PROCEDURE [dbo].[usp_GetDefaultValue]

    @Service varchar(20), @LOB varchar(10), @Scenario varchar(20), @Num varchar(10)

AS
BEGIN

    SET NOCOUNT ON;
    DECLARE @val as int
    DECLARE @val1 as int
    DECLARE    @Value  AS NVARCHAR(MAX)
    DECLARE    @DefValue  AS NVARCHAR(MAX)

    set @Value =  'SELECT '  + @Service + ' from PDetail where LOB = ''' + @LOB  + ''' and Scenario =  ''' + @Scenario + '''  and Number = ''' + @Num + ''' '  -- query 1
    set @DefValue =  'SELECT '  + @Service + ' from PDetail where LOB = ''' + @LOB  + ''' and Scenario =  ''none''  and Number =''none''  and pid = 1'         -- query 2

    exec @val = sp_executesql @Value
    exec @val1 = sp_executesql @DefValue

    if (@val1 = 0 or @val1 = null)  
        begin
            set @DefValue = null
            set @DefValue =  'SELECT '  + @Service + ' from PDetail where LOB = ''' + @LOB  + ''' and Scenario =  ''none''  and pid = 2'               -- query 3
            exec @val1 = sp_executesql @DefValue
        end

    select @val,@val1  -- want to return only two values

END

我建议你换衣服

  if (@val1 = 0 or @val1 = null) 

到

请记住，这是SQL，检查null的正确方法是使用
is null
您遇到了什么问题？请具体说明每当我看到这样的问题时，我总是认为主要问题是糟糕的表设计/结构。@Jeffrey Wieder:更新了我遇到的问题。请阅读Erland Sommarskog的。您的代码存在SQL注入的风险。
  if (@val1 IS NULL or @val1 = 0)