SQL CASE WHEN或IF ELSE IF

Question

我有多个条件的情况下 满足我想知道如果我可以使用> <，而不是界定每一个案件

在这种情况下，当信用评级是小然后3然后，“否TRADE”将在

SELECT ClientId, 
    FirstName, 
    LastName, 
    Gender, 
    DateOfBirth, 
    CreditRating, 

     CASE CreditRating 

      WHEN 0 THEN 'NO TRADE' 
      WHEN 1 THEN 'NO TRADE' 
      WHEN 2 THEN 'NO TRADE' 
      WHEN 3 THEN 'POOR' 
      WHEN 4 THEN 'POOR' 
      WHEN 5 THEN 'AVARAGE' 
      WHEN 6 THEN 'AVARAGE' 
      WHEN 7 THEN 'GOOD' 
      ELSE 'PERFECT' 

      END AS RATING 

    FROM dbo.client 

Answer 1

当然有可能插入在字 和更大然后3，更小，然后5将是“差”，等等等等。

 CASE 

     WHEN CreditRating <= 2 THEN 'NO TRADE' 
     WHEN CreditRating <= 4 THEN 'POOR' 
     WHEN CreditRating <= 6 THEN 'AVARAGE' 
     WHEN CreditRating = 7 THEN 'GOOD' 

     ELSE 'PERFECT' 

     END AS RATING