Further to postgres on Rails in Fedora 18 but OT

[Bruno Wolff III]

On Thu, May 16, 2013 at 19:57:46 +1000,
   Roger <arelem at bigpond.com> wrote:
>
>In sqlite, the string tables contain numbers so the rails to_i 
>changes them to integer for adding.
>How can I do this with postgres please?

You can cast text to integer using ::integer. For example:
bruno=> select '123'::text::integer;
  int4 
------
   123
(1 row)

>Thanks in advance
>Roger
>
>The reason I didn't make the numeric fields integer, is because Rails 
>likes to have a select system for fields inputting integers and I do 
>not want this.

If you do this, I recommend putting a constraint on the fields so that 
they can only be integers. You can use regular expressions to do the 
matching.

>I have been searching on google all day for answers but as usual, 
>responses from Rails officianados is curt and  lacks explanation.

For postgres questions I would start by looking at the postgres documentation. 
It is very good.

In this case it might not be obvious where to look, but what you want is 
covered under type casts.
http://www.postgresql.org/docs/9.2/static/sql-expressions.html#SQL-SYNTAX-TYPE-CASTS

Note in my example above I used the :: notation because it is a lot more 
convenient to type than using the SQL standard CAST function. But you 
don't want to use that in real code as it will make it harder to switch 
databases later.

If you want to using formatting when converting between strings and numbers 
(mostly going from numeric types to string types) you can look at:
http://www.postgresql.org/docs/9.2/static/functions-formatting.html