At 11:29 AM 4/30/04, Yudie wrote:
>Great the function works, but what does it means?
>SELECT $1 ~ ''^[0-9]+$''
>
>Yudie
The ~ is a pattern matching operator. ^ matches beginning of string [0-9] matches any numeric digit 0
thru9. + matches one or more occurrences of what came before (digits in
this case) $ matches end of string
The ^ and $ are important - if they were left out, the pattern would match
a string containing both numeric and non-numeric data.
You can change the + to * if you decide that an empty string should be
considered numeric.
Frank