-1
votes
1answer
28 views

Inserting null value without quotes postgresql

I'm creating a php application which relies on postgresql. Now i have this query: $query= 'INSERT INTO "users" ("name", "username", "email", "phone") VALUES (\''. $name .'\', \''. $username .'\', ...
0
votes
1answer
21 views

Return a default value in group by if selected column is null

I am trying to run a group by statement which works fine however, one of the "group" is null. How do I return "Unknown" for that row? For example: 10000 A 9999 B 9990 C 4 etc. First ...
1
vote
1answer
97 views

Alternatives to NULL for missing data [duplicate]

I am using PostgreSQL and trying to write value constraints. Is it possible to record missing data as distinct from NULL values in a numeric field without using an arbitrary numeric value? For many ...
1
vote
2answers
131 views

Returning empty string when string_agg has no records

I am trying to return a text field in a PostgreSQL query that is of the form 'stringOne' || string_agg(field, ',') || 'stringTwo' where for certain elements in the group clause, field is always ...
10
votes
3answers
408 views

Can IS DISTINCT FROM be combined with ANY or ALL somehow?

Is a postgres way of combining IS DISTINCT FROM with ANY or some other neat way of getting the same result? select count(*) from (select 'A' foo union all select 'Z' union all select null) z where ...
1
vote
3answers
710 views

Select query to retrieve values even if are null

I need some help in a query. Need to retrieve data from 1 table, even if one of the field has null value. Here's an example: Select name, SUM(credit) as credit From expenses Where name like ...
1
vote
0answers
53 views

How to merge rows based on how much data they have?

I am cleaning data and I formed a table something like this: file | product | color | product_id --------------------------------------------- one.csv pipe blue null ...
1
vote
3answers
5k views

Getting SELECT to return a constant value even if zero rows match

Consider this select statement: SELECT *, 1 AS query_id FROM players WHERE username='foobar'; It returns the column query_id with value 1 along with a player's other columns. How would ...
10
votes
1answer
892 views

Why does NOT IN with a set containing NULL always return FALSE/NULL?

I had a query (for Postgres and Informix) with a NOT IN clause containing a subquery that in some cases returned NULL values, causing that clause (and the entire query) to fail to return anything. ...
16
votes
3answers
9k views

PostgreSQL multi-column unique constraint and NULL values

I have a table like the following: create table my_table ( id int8 not null, id_A int8 not null, id_B int8 not null, id_C int8 null, constraint pk_my_table primary key (id), constraint ...
3
votes
1answer
562 views

PostgreSQL pl/perl trigger, differentiate null vs empty

I've been trying to speed up a generic auditing trigger that I had written in pl/pgsql some time back. On update, it generates a list of columns in the table being updated and inserts rows in the ...
3
votes
2answers
1k views

PostgreSQL: count datasets / lines containing NULL values

I'm looking for a easy function to get the number of datasets (of any table) containing NULL values. It's not important how many columns are involved. For example: CREATE TABLE tab1 ( id INTEGER ...
6
votes
4answers
3k views

Finding empty columns of a table in PostgreSQL

What query would return the name of the columns of a table where all rows are NULL?