我可以一起使用COUNT（）和DISTINCT吗？

Question

I would like to count the number of rows from a mysql table and not to include duplicate entries,

Could I use distinct with count() ?

Answer 1

当然。

SELECT COUNT(DISTINCT column) FROM table;

Answer 2

What you need is the following:

SELECT field_type_name, count(*) FROM fields GROUP BY field_type_name;

This will give you something like this:

image   14
string  75
text     9

Answer 3

 SELECT COUNT(DISTINCT field) from Table

看到这个 。

Answer 4

SELECT count(DISTINCT column Name) as alias from table_Name;