Question

select column1,column2,column3 from table1 where column5=0 and column6=0
select column1,column2,column3 from table1 where column5!=0 and column6!=0

这两个sql语句从同一个table1读取数据。有没有办法编写一个返回相同数据的查询？

我想在单个查询中获得（column5 = 0 AND column6 = 0）和（column5！= 0 AND column6！= 0）的单独结果。

as example:
select column1 as c1,column2 as c2,column3 as c3 from table1 where column5=0 and  column6=0
union
select column1 as c1_,column2 as c2_,column3 as c3_ from table1 where column5!=0 and column6!=0

Answer 1

SELECT column1, column2, column3 
FROM table1 
WHERE (column5 = 0 AND column6 = 0) OR (column5 != 0 AND column6 != 0)

Answer 2

如果您希望从单个结果集中的两个查询中获取所有结果，则可以像这样使用UNION：

select column1,column2,column3 from table1 where column5=0 and column6=0
union
select column1,column2,column3 from table1 where column5!=0 and column6!=0

Answer 3

如其他人所提到的，您可以使用UNION。为了识别哪些记录来自哪个查询，你可以这样做：

select 'query1', column1,column2,column3 from table1 where column5=0 and column6=0
union
select 'query2', column1,column2,column3 from table1 where column5!=0 and column6!=0

然后在记录集处理中，您可以检查第一个值并决定如何处理其余值。

Answer 4

SELECT column1,column2,column3 from table1 where (column5=0 and column6=0) or (column5!=0 and column6!=0)

Answer 5

如果我理解正确，你想要将结果的两个部分分开。为此添加ORDER BY子句。

SELECT column1, column2, column3 
FROM   table1 
WHERE  (column5 =  0 AND column6 =  0)
    OR (column5 != 0 AND column6 != 0)
ORDER  BY (column5 = 0) DESC -- it's enough to include one column in this case.

如果您还希望能够区分它们，请添加另一个表示原点的列：

SELECT (column5 = 0) AS first_part, column1, column2, column3 
FROM   table1 
WHERE  (column5 =  0 AND column6 =  0)
    OR (column5 != 0 AND column6 != 0)
ORDER  BY 1 DESC;

Answer 6

select 
sum(
 case when (column5=0 or column6=0 ) 
 then 1 else 0 end 
   ) as c1 ,

 sum(
 case when (column5=0 or column6=0 ) 
 then 1 else 0 end 
   ) as c2 ,
 sum(
 case when (column5=0 or column6=0 ) 
 then 1 else 0 end 
  ) as c3 ,

sum(
 case when (column5!=0 or column6!=0 ) 
 then 1 else 0 end 
) as c1_ ,

  sum(
 case when (column5!=0 or column6!=0 ) 
 then 1 else 0 end 
  ) as c2_ ,
 sum(
 case when (column5!=0 or column6!=0)  
 then 1 else 0 end 
   ) as c3_ ,

from table1

为具有相同条件的同一个表的多个查询编写单个查询

6 个答案: