Re: How does one perform a case-insenstive query on test or char fields - Mailing list pgsql-general

From Chad Wagner
Subject Re: How does one perform a case-insenstive query on test or char fields
Date
Msg-id 81961ff50701101511u31fb91dek892afe43a83e0263@mail.gmail.com
Whole thread Raw
In response to How does one perform a case-insenstive query on test or char fields  (af300wsm@gmail.com)
List pgsql-general


On 9 Jan 2007 13:44:32 -0800, af300wsm@gmail.com <af300wsm@gmail.com > wrote:
SELECT * FROM table WHERE thisfield = 'some text';

How would I rewrite this query to search through the table looking at
the text in the column "thisfield" for the string "some text" but have
it perform a case insensitive search?

I wouldn't consider this a "search", but rather a lookup.  You can find some tips on how to do this in the link below.

http://archives.postgresql.org/pgsql-php/2003-05/msg00045.php


If you need "thisfield" to be indexed, then I would suggest creating an index on the expression "LOWER(thisfield)", the below text is directly from the user guide:

For example, a common way to do case-insensitive comparisons is to use the lower function:

SELECT * FROM test1 WHERE lower(col1) = 'value';

This query can use an index, if one has been defined on the result of the lower(col1) operation:

CREATE INDEX test1_lower_col1_idx ON test1 (lower(col1));

You can read more about expression indexes here:

http://www.postgresql.org/docs/8.2/static/indexes-expressional.html



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