Re: LIKE predicate and '\' character

On Wed, Nov 07, 2001 at 12:56:46PM -0000, Andy Hallam wrote:

The PostgreSQL parser "eat" one '\' on arbitrary place in query. You
you want put '\' to some function (operator) you must use '\\'.

test=# select '\\';
?column?
----------
\
(1 row)

test=# select '\\\\';
?column?
----------
\\
(1 row)

test=# select 'hello\\pg' like 'hello\\pg';
?column?
----------
f
(1 row)

test=# select 'hello\\pg' like 'hello\\\\pg';
?column?
----------
t
(1 row)

Karel

> PostgreSQL - 7.1.3 (installed on Linux 2.4.2-2)
> PSQLODBC.DLL - 07.01.0007
> Visual C++ - 6.0
>
> I sent a previous mail with regard to using the '\' (backslash) character in
> an SQL SELECT statement.
> The outcome was that postgres does not escape the '\' itself - I need to do
> it myself before submitting the SQL - fair enough, I now do this.
>
> i.e
> instead of
> mydb=# SELECT * FROM users WHERE id = 'WORKGROUP\me';
> I now do
> mydb=# SELECT * FROM users WHERE id = 'WORKGROUP\\me';
>
> BUT, if I use the LIKE predicate I have to escape the escape.
>
> i.e
> mydb=# SELECT * FROM users WHERE id LIKE 'WORKGROUP\\\\me';
>
>
> Now this must be treated as a bug.
> As you can see it is not an error with the PSQLODBC driver as I ran the SQL
> from the command line with the same results.
> I am presuming that the backend parsing logic around the LIKE prodicate is
> ignoring the '\'.
>
> Is anyone working on this ?. Can anyone send me a fix, as without this I'm
> screwed.
>
> Thanks for any help
>
> Andy.
> ahm(at)exel(dot)co(dot)uk
>
>
>
>
>
>
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--
Karel Zak <zakkr(at)zf(dot)jcu(dot)cz>
http://home.zf.jcu.cz/~zakkr/

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