如何在一个sql表中计算来自同一字段的不同行

Question

hi I have one table which I am trying to get the count of different rows on the same row field for example I a have this rows

Function field1 field2 field3
'dog'    1      1      5
'dog'    1      1      5
'cat'    1      1      5
'dog'    1      2      6

The output for this table should be:

Function count
'dog'    2
'cat'    1

because there are two different rows for 'dog' (some of the field are different) and one row for 'cat'

thank you so much

Answer 1

Assuming that you want to count rows identical based on a given subset of fields, this would be:

 SELECT func, COUNT(*) FROM (
     SELECT DISTINCT func, field1, field2 FROM yourtable
 ) AS tmp GROUP BY func;

This first distincts all the rows, so you get

'dog'    1      1      5
'cat'    1      1      5
'dog'    1      2      6

and then counts the first field, thus giving 2 and 1.

You can even do something like

 SELECT func, COUNT(*) AS different, SUM(total) AS total FROM (
     SELECT   func, field1, field2, field3, COUNT(*) AS total 
            FROM yourtable
     GROUP BY func, field1, field2, field3
 ) AS tmp GROUP BY func;

which will give:

 func   different   total
 dog    2           3
 cat    1           1

Answer 2

This should give you the results you are looking for:

Select  Function, Count(*) As Count
From
(
    Select  Distinct
            Function,
            Field1,
            Field2,
            Field3
    From    YourTable
) As A
Group By Function