sql 问题....

[boytomato]

a 表(字段1,......)
(满意,......)
(不满意,....)

b 表(字段1,.....)
(满意,......)
(不满意,.....)
综合统计 a 表和 b 表中字段 1的比率,
即,(a 中的字段1字段1 ' 满意'所的条数 +b 表中字段1'满意'所点条数)
/(a中记录条数+b中记录条数)，即比率。
我问过一次不过在 delphi 不能通过。。。。。

[hiflower]

难道上次那个语句还不行吗？你是什么数据库啊？

[boytomato]

access .

[ntn115]

SQL的GROUP BY 字段1 HAVING 字段1=‘满意’
方法这样了，你自己看看，SQL的分组

[47522341]

var a1,a2,b1,b2: integer;
pre: double;
begin
with adoquery1 do
begin
close;
sql.clear;
sql.text := 'select count(*) as a from a表 where 字段1 = 满意';
open；
a1 := fieldbyname('a').integer;


close;
sql.clear;
sql.text := 'select count(*) as a from b表 where 字段1 = 满意';
open；
b1 := fieldbyname('a').integer;


close;
sql.clear;
sql.text := 'select count(*) as a from a表 ';
open；
a2 := fieldbyname('a').integer;


close;
sql.clear;
sql.text := 'select count(*) as a from b表 ';
open；
b2 := fieldbyname('a').integer;

end;

pre := (a1 + b1)/(a2 + b2)
end;

[47522341]

不好意思楼主；我对sql不熟悉；^_^；

[hiflower]

SELECT CountDD/CountTotal AS Ratio
FROM [SELECT 1 AS tempfield, COUNT(*) AS CountDD
FROM (SELECT *
FROM info1
UNION
SELECT *
FROM info2) x
WHERE x.info = '满意']. AS A LEFT JOIN [SELECT 1 AS tempfield,COUNT(*) AS CountTotal
FROM (SELECT *
FROM info1
UNION
SELECT *
FROM info2) y]. AS B ON A.tempfield=B.tempfield;

[boytomato]

都不行.....

[hiflower]

ACCESS 嘛，我试过行啊
你可以先试试其中的每个子查询，看看 CountDD 和 CountTotal 的结果是否正确。

下面我作了一些改进，以防有两个表出现完全相同的记录。


SELECT CountDD,CountTotal,CountDD/CountTotal AS Ratio
FROM [SELECT 1 AS tempfield, COUNT(*) AS CountDD
FROM (SELECT *,1
FROM info1
UNION
SELECT *,2
FROM info2) x
WHERE x.info = '满意']. AS A LEFT JOIN
[SELECT 1 AS tempfield,COUNT(*) AS CountTotal
FROM (SELECT *,1
FROM info1
UNION
SELECT *,2
FROM info2) y]. AS B ON A.tempfield=B.tempfield;

[ghostmaster]

gz!