SQL如果value为零,则不返回列

Question

此查询返回一行,其中包含"准备","处理","完成","失败"和"错误"列,每行包含总计.有没有办法重写此查询,以便不返回总计为零的列？

我正在使用它来填充mschart控件,如果该类别有0个实例,我不会在图表上标记.

SELECT        
              SUM(CASE WHEN Status = 'R' THEN 1 ELSE 0 END) AS Ready,
              SUM(CASE WHEN Status = 'P' THEN 1 ELSE 0 END) AS Processing, 
              SUM(CASE WHEN Status = 'C' THEN 1 ELSE 0 END) AS Complete,
              SUM(CASE WHEN Status = 'F' THEN 1 ELSE 0 END) AS Failed,
              SUM(CASE WHEN Status = 'E' THEN 1 ELSE 0 END) AS Error
FROM  MailDefinition 

Answer 1

不,因为必须知道查询的形状(它包含的字段).只有数据可以改变,这就是你应该寻找的东西.您可以根据列中的数据0或null数据动态删除或隐藏标签.