Is there a way to count the number of different values?

Question

Is there a way to count the number of different values?

In PostgreSQL 9.4, I have a table:

id         p_id
PK        integer
-----------------
1           1
2           1
.............
123122       2233

Is there a way to count all the different values p_id

in a table with just one query ( without using subqueries ). I can use any window function.

+3

sql select postgresql distinct-values

user3663882 June 20. At 13:01

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1 answer

Mureinik · Accepted Answer · 2015-06-20T13:02:20+0000

You can use a modifier distinct

in a function count

:

SELECT COUNT(DISTINCT p_id) FROM mytable

Is there a way to count the number of different values?

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