如何使用通配符参数和其他参数过滤数据？

Question

ALTER PROCEDURE MyProcName 
    @IsMatch varchar(50)
AS
    SELECT
        IMS_PolicyNumber, Rater_PolicyNumber
    FROM
        tblPolicies 
    WHERE
        (@IsMatch = 'No Match' AND Rater_PolicyNumber <> IMS_PolicyNumber OR Rater_PolicyNumber IS NULL) -- returns No Match records
        OR (@IsMatch = 'Match' AND Rater_PolicyNumber = IMS_PolicyNumber) --Returns Matching Records
        OR (@IsMatch = 'Both') --Returns both: matching and no matching records 

但现在我想添加通配符参数@Rater_PolicyNumber，这样用户就可以只输入Rater_PolicyNumber 的第一个字母并过滤结果，或者如果用户将其留空，则忽略此参数：

AND @Rater_PolicyNumber LIKE COALESCE('%'+ @Rater_PolicyNumber+'%','') 

但我很难让它与@IsMatch 参数一起工作：

如果我在@Rater_PolicyNumber 中传递值，则以下内容有效，但如果我将其留空 - 它会返回所有记录，而不仅仅是不匹配的记录。

WHERE
    ((@IsMatch = 'No Match' AND Rater_PolicyNumber <> IMS_PolicyNumber OR Rater_PolicyNumber is null) 
     OR Rater_PolicyNumber LIKE COALESCE('%'+ @Rater_PolicyNumber+'%',''))

我如何返回“不匹配”、“匹配”和“两者”记录，并仅在用户输入时才按@Rater_PolicyNumber 值过滤它们。

谢谢

Answer 1

使用多个and 和or 可能会变得很棘手。我已经应用了一些格式并在这些部分周围添加了括号以返回最初返回的记录，但如果@Rater_PolicyNumber 不为空，它也会应用like。

select IMS_PolicyNumber
  , Rater_PolicyNumber
from tblPolicies 
where (
       Rater_PolicyNumber like '%'+ @Rater_PolicyNumber+'%'
       or Rater_PolicyNumber is null
       or @Rater_PolicyNumber is null 
      )
  and (
        (@IsMatch = 'No Match' 
         and (Rater_PolicyNumber<>IMS_PolicyNumber 
              or Rater_PolicyNumber is null) 
          )
      -- returns No Match records
       or (@IsMatch= 'Match' and Rater_PolicyNumber=IMS_PolicyNumber) 
      -- Returns Matching Records
       or (@IsMatch = 'Both') 
      --Returns both: matching and no matching records 
      )

Answer 2

你可以试试这个吗？

        SELECT
            IMS_PolicyNumber, Rater_PolicyNumber
        FROM
            tblPolicies 
        WHERE CHARINDEX(@IsMatch,CASE WHEN  Rater_PolicyNumber = IMS_PolicyNumber THEN 'Match,Both' ELSE 'No MATCH,Both' END)>0