Go Premium for a chance to win a PS4. Enter to Win


Postgresql function returning select query

Posted on 2002-07-10
Medium Priority
Last Modified: 2008-02-01

I'm pretty novice to Postgresql, and I wonder how I could do this ...

In M$ SQL Server, you can create a procedure like this:

create procudure test () as
  select * from mytable

In Postgresql, you can create functions returning rows too.  You have to declare your return value as the name of a table.

In the above case, this would be:
create function test() returns setof mytable as
' select * from mytable
' language 'sql';

But, what if I wanted to join two tables, how do I return results then ?

What I want, is the equivalent to this M$ SP:

create procedure test ()
  select field1, field2 from table1, table2
  where table1.field = table2.field

I want this because I like to create procedures (or functions) that hold my queries, rather than having them executed from within some other part of my code.

In Visual Basic, I'm used to creating ADO recordsets based on simple stored procedures like the one above.  I'd like to do similar things in Postgresql.
Question by:vindevogel

Expert Comment

ID: 7145218
vindevogel  Could u give me any links to tutorials on postgres stored procedures? I am looking for any such docs..and I'm sorry I cant answer ur question at this time..

Expert Comment

ID: 7226863
vindevogel - Why not just store your queries as views? Honestly, it seems to me that it is a serious waste of resources to create a procedure simply to process a query. That is exactly what views are for. (And also, that is your answer for how to return a joined query: make a view, and query the view in your stored procedure, if you really must do that...)

Generally, though, you should only use procedures for special data manipulation that you can't handle in a regular SQL query. If you don't want to 'see' the query in your application code, you should just create a standard include file that defines your queries. The whole point of a SQL DBMS is that it has a standardized interface (SQL), so that portability between applications and between DBMS's is fairly simple. Once you start stuffing everything away into stored procedures, you will have a headache every time you migrate. (I have one potential client that now needs to migrate 2500 stored procedures from SQL Server 7 to Oracle. This is a perfect example of someone mistakenly thinking you should use a procedure for everything. It might seem simple at first, but creates many headaches later :-(. )
LVL 54

Expert Comment

ID: 7294270

No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:
 - PAQ'd and pts removed
Please leave any comments here within the
next seven days.



Accepted Solution

ComTech earned 0 total points
ID: 7314784
This question will be placed in PAQ and points refunded.

Best regards,
Community Support
Administrator @ EE

Featured Post

NEW Veeam Backup for Microsoft Office 365 1.5

With Office 365, it’s your data and your responsibility to protect it. NEW Veeam Backup for Microsoft Office 365 eliminates the risk of losing access to your Office 365 data.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Lotus Notes has been used since a very long time as an e-mail client and is very popular because of it's unmatched security. In this article we are going to learn about  RRV Bucket corruption and understand various methods to Fix "RRV Bucket Corrupt…
Creating a Cordova application which allow user to save to/load from his Dropbox account the application database.
Video by: Steve
Using examples as well as descriptions, step through each of the common simple join types, explaining differences in syntax, differences in expected outputs and showing how the queries run along with the actual outputs based upon a simple set of dem…
This lesson discusses how to use a Mainform + Subforms in Microsoft Access to find and enter data for payments on orders. The sample data comes from a custom shop that builds and sells movable storage structures that are delivered to your property. …
Suggested Courses

877 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question