审判案件https://www.w3schools.com/sql/func_mysql_case.asp
像这样：

SELECT   Postcode, Cost =  
      CASE 
         WHEN Postcode LIKE '4%' THEN 8.00  
         WHEN Postcode LIKE '2%' THEN 4.65   
         ELSE 'unknown'  
      END

或

SELECT   Postcode, Cost =  
          CASE  
             WHEN Postcode  BETWEEN '1000' AND '1999' THEN 8.00  
             WHEN Postcode  BETWEEN '2000' AND '2999' THEN 4.65   
...
             ELSE 'unknown'  
          END