选择“区分多个”列，将“不重复”计数

Question

How do you select distinct, and count of distinct? I have a table:

col1    col2
 1       1
 1       0
 0       0
 0       1
 1       1
 0       0

And I'm trying to get this:

col1    col2    count
 1       1        2
 1       0        1
 0       0        2
 0       1        1

Answer 1

You just need to use GROUP BY clause with multiple columns.

SELECT col1, col2, COUNT(*) FROM Table1
GROUP BY col1, col2