Re: [GENERAL] LIKE operator

[Charset iso-8859-1 unsupported, filtering to ASCII...]
> Hi,
>
> With mSQL I used to perform queries like below from within PHP:
>
>   select field1, field2 from table1 where field1 like '%$some_variable%'
>
> where the '%' in the LIKE clause matches 0 or more characters of any value.
> That is, the query above would match the strings that contain
> '$some_variable' OR any string if $some_variable is empty.
>
> For example: my table has two rows with the first record containing
> field1='abc' and the second record containing field1='cde'.
>
>   If '$some_variable' is empty, then my query would return both rows.
>   If $some_variable='bc', then the query would return only the row where
> field1='abc'.
>
> With PostgreSQL I experience the following:
>
>   If '$some_variable' is empty, then my query returns *nothing*.
>   If $some_variable='bc', then the query would return only the row where
> field1='abc'.
>
> As the value of '$some_variable' is to be filled by some user while posting
> a form, I don't know in advance if it is going to be empty or not.
>
> How can I make the query results to be exactly as with mSQL without having
> to alter my query 'throwing out' every part of the 'where' clause where
> '$some_variable' is empty?
>

With 6.5 beta, I get:

    test=> create table t (x text);
    CREATE
    test=> insert into t values ('abc');
    INSERT 18697 1
    test=> insert into t values ('bcd');
    INSERT 18698 1
    test=> select * from t where x like '%%';
    x
    ---
    abc
    bcd
    (2 rows)

Not sure what 6.4 does, but I will say I overhauled the LIKE code in
6.5beta.


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