结合了两个SQL SELECT COUNT（*）语句

Question

我正在使用Microsoft Access 2007.我有两个SELECT COUNT（*）语句，它们在没有合并的情况下正常运行，但我想将这些语句合并为一个通过VBA作为表单记录源。

1. SELECT Count(*) AS OrderCount FROM (SELECT DISTINCT OrderNo FROM tblDisposition);" 

2. SELECT Count(*) AS ReviewCount FROM tblDisposition WHERE [ReviewClose]=0; 

我知道已经有很多这样的问题，如：

two SQL COUNT() queries?

Access 2007: "SELECT COUNT(DISCTINCT ..."

How do I combine 2 select statements into one?

等等。这是我做过尝试，但还是失败了：

SELECT (SELECT Count(*) AS OrderCount FROM (SELECT DISTINCT OrderNo FROM tblDisposition))," 
     (SELECT Count(*) AS ReviewCount FROM tblDisposition WHERE [ReviewClose]=0);" 

我设置的结合SQL语句对myForm会为记录源和我有两个文本框，我设置控件的定单计数和ReviewCount。在我设置recorsource的表单加载事件中，两个文本字段都给出了#NAME错误，但是如果我只设置一个SQL语句，它将在文本字段上显示正确的计数。

Answer 1

可以使用下面的SQL语句得到这两方面作为一个单列的两个值一种让查询返回单行的方法。这也可以用Dual表完成，如here所述。

Answer 2

我想你的查询根本不起作用。尝试添加“* FROM”是这样的：

SELECT 
    (
     SELECT Count(*) AS OrderCount 
     FROM 
      (
       SELECT DISTINCT OrderNo FROM tblDisposition 
      ) 
    ) AS OrderCount, 
    (
     SELECT Count(*) AS ReviewCount 
     FROM tblDisposition 
     WHERE [ReviewClose]=0 
    ) AS ReviewCount 
FROM 
    (
     SELECT COUNT(*) FROM tblDisposition 
    ) 

注意，最终FROM条款实际上就是：

SELECT * FROM 
(SELECT Count(*) AS OrderCount FROM (SELECT DISTINCT OrderNo FROM tblDisposition)), 
(SELECT Count(*) AS ReviewCount FROM tblDisposition WHERE [ReviewClose]=0)