Re: Cast

#1

Eduardo Vázquez Rodríguez wrote:

Quote:

I made I mistake choosing the data types in my database I try to run a
query that look like this
Duration data type is varchar

SELECT name, SUM(duration) AS total
FROM table
GROUP BY name
HAVING name != 'John'

I get the following error:
ERROR: function sum(character varying) does not exist
HINT: No function matches the given name and argument types. You may
need to add explicit type casts.

1. How can I made a cast on the query from varchar to int?

Try with:

.... SUM(duration::integer) ...

Quote:

2. If I change the datatype on the database from varchar to int, do I
loose all the data on that field?

You can create a new integer column, copy all datas from the old
VARCHAR column to the new one and with a rename column and a remove column
you finish...

Regards
Gaetano Mendola

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Re: Cast

comp.databases.postgresql.novice comp.databases.postgresql.novice

Re: Cast - 09-08-2004 , 06:18 PM