sql在查询中解决增长问题

Question

我正在努力计算2年之间增长的百分比，但它将增长率恢复为0。

SELECT my.finmonth,
   my.trnyear,
   my.drawofficenum,
   my1.ytdty,
   ly1.ytdly,
   CASE
     WHEN my1.ytdty <> 0 THEN ( my1.ytdty - ly1.ytdly ) / ly1.ytdly * 100
     ELSE 0
   END AS Growth2012
FROM   salestymonth my
   LEFT JOIN salestyytd my1
          ON my.finmonth = my1.finmonth
             AND my.trnyear = my1.trnyear
             AND my.drawofficenum = my1.drawofficenum
   LEFT JOIN saleslyytd ly1
          ON my.finmonth = ly1.finmonth
             AND my.trnyear = ly1.trnyear
             AND my.drawofficenum = ly1.drawofficenum
WHERE  my.finmonth = '1'
ORDER  BY ytdty DESC  

Answer 1

尝试1.00 *（my1.YTDTY - ly1.YTDLY）/ ly1.YTDLY。如果您的列类型是整数，除非您强制分子为小数或浮点数，否则不会从除法中得到非整数结果。