2
votes
1answer
27 views

Best way of finding rows referencing a given id on PostgreSQL

I'm trying to find if there would be anything violating the foreign key constraint when deleting a row, to check if I can delete it or not (can't use ON DELETE CASCADE) For that, I have a piece of ...
0
votes
1answer
50 views

Is there a faster way to get UNION ALL behavior in Postgres?

I have a table (t0), in my Postgres DB, with data that looks something like this: t1_id t2_id 1 1 2 1 2 1 4 null 4 null 5 null And I have a query to return my ...
0
votes
2answers
46 views

Calculating average with AVG for a list of numbers

This is probably a newbie question (bear with me) but how can I calculate the average for a list of numbers using SQL and the AVG function? I mean, I can add together numbers in SQL like: SELECT ...
0
votes
1answer
120 views

Query improvements without UNION

I have the following scenario. A users table, a records table and a memberships table. A user can be associated to zero or more records either directly with the records table records.user_id = ...
-1
votes
1answer
140 views

Group by for UNION not working Postgresql

I can't find a way to make Group by works in Postgresql, How can i make group by works so each name will be only one , not repeated many times like what i got in this picture? Here is a code for what ...
1
vote
1answer
426 views

Postgres: “Pivot” unioned table based on one column

I have a query that does this sort of thing: (SELECT rel_id, timestmap, y FROM table_1 AS full_ WHERE full_.timestamp BETWEEN %s AND %s ORDER BY full_.timestamp) UNION ALL (SELECT rel_id, ...
2
votes
2answers
1k views

Postgres 9.2 select multiple specific rows in one query

I have a table with three columns, Id Serial. Value real. timein Timestamp. I want to select the values based on a range of days ie. from two days ago until now. The table may contain one or two ...