Re: please help me on regular expression

2010/2/2 Tena Sakai <tsakai(at)gallo(dot)ucsf(dot)edu>:
> Hi everybody,
>
> I need a bit of help on postgres reqular expression.
> With a table of the following definition:
>
>           Table "tsakai.pheno"
>  Column   |       Type        | Modifiers
> -----------+-------------------+-----------
>  subjectid | integer           | not null
>  height    | character varying | not null
>  race      | character varying | not null
>  blood     | character varying | not null
>
> I want to catch entries in height column that includes a
> decimal point.  Here's my attempt:
>
>  select subjectid, height
>   from tsakai.pheno
>  where height ~ '[:digit:]+.[:digit:]+';
>
> Which returns 0 rows, but if I get rid of where clause,
> I get rows like:
>
>  subjectid | height
> -----------+--------
>     55379 | 70.5
>     55383 | 69
>     55395 | 70
>     56173 | 71
>     56177 | 65.5
>     56178 | 70
>       .      .
>       .      .
>
> And when I escape that dot after first plus sign with a backslash,
> like this:
>  where height ~ '[:digit:]+\.[:digit:]+';
> then I get complaint:
>
> WARNING:  nonstandard use of escape in a string literal
> LINE 3: where height ~ '[:digit:]+\.[:digit:]+';
>                       ^
> HINT:  Use the escape string syntax for escapes, e.g., E'\r\n'.
>
> From there, it was a downward spiral descent...
>

you have to use a prefix 'E' - E'some string with \backslash'

for your case the reg. expr could be

postgres=# select '70.5' ~ e'\\d+\.\\d+';
?column?
----------
t
(1 row)

http://www.postgresql.org/docs/8.1/static/functions-matching.html

or

postgres=# select '70.5' ~ e'[[:digit:]]+\.[[:digit:]]+';
?column?
----------
t
(1 row)

Regards
Pavel Stehule
> Please help.
>
> Thank you.
>
> Regards,
>
> Tena Sakai
> tsakai(at)gallo(dot)ucsf(dot)edu
>
>
>
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