PostgreSQL How to use a CSV in a query

Question

Ok I am very new to postgres so bear with me. I have been using the string_agg function in postgres to get my CSV. I want to know how to use my CSV in a query. I did this in SQL server by using a DECLARE but as I have read there is not a way to DECLARE globally in postgres. Any help, documentation, examples would be greatly appreciated.

To be honest i don't know what you're trying to achive. I don't see correlation between string_agg and DECLARE. Do you want to create CSV? or process given file? or do you just look for DECLARE equivalent? What have you done yet and what's your particular problem? — Gabriel's Messanger
– Gabriel's Messanger, Commented Oct 9, 2015 at 13:24
I guess I should clarify. I want to use string_agg like a CSV (Comma Sperated Value). So when I use it I can get a listing of lets say recordIDs. Now I want to use the that list in a function. — Louis Royster
– Louis Royster, Commented Oct 9, 2015 at 13:28
A very simple example of this would be running a string_agg to get all recordIDs that are less than 100. Then write a query 'code' Select * From Table1 Where recordID(string_agg) — Louis Royster
– Louis Royster, Commented Oct 9, 2015 at 13:31

Gabriel's Messanger · Accepted Answer · 2015-10-09 14:01:36Z

1

Ok, so based on your question and your comment. PostgreSQL has ARRAY type which fits nicely in SQL statements, so you can make an array from your CSV-string and use it in queries like:

SELECT * FROM table WHERE record_id = ANY(string_to_array( string_agg , ','));

Actually there is no need to use CSV at all. If you have such option change to use array_agg in the first place (instead of string_agg).

Function string_to_array(text, delimiter) splits string into array with delimiter passed as an argument. Expression record_id = ANY( array ) returns TRUE when "any" of the array elements is equal to record_id and FALSE otherwise.

edited Oct 9, 2015 at 14:01

answered Oct 9, 2015 at 13:45

Gabriel's Messanger

3,36822 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

PostgreSQL How to use a CSV in a query

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related