Question

How to validate zipcode using regular expression?

It should be in the following pattern:-

[A-z][0-9][A-Z] [0-9][A-Z][0-9]

E.g.

B5D 2M4 
b5d 2m4 

I am using Oracle9i.

Thanks in advance,
Shubhojwal Ghosh

Answer 1

Unfortunately, since you are using a very old version of Oracle, you cannot use the standard regular expression functions like REGEXP_LIKE. If you were to upgrade to a moderately recent version of Oracle, that would be the way to go.

In older versions of Oracle, you would have to use the OWA_PATTERN package. Note that since the OWA_PATTERN.MATCH function returns a BOOLEAN, you cannot call it from SQL, just from PL/SQL. You could, of course, create your own wrapper function that returns an integer or a string to indicate whether the ZIP code is valid.

SQL> ed
Wrote file afiedt.buf

  1  declare
  2    function is_valid_zip( p_zip_code in varchar2 )
  3      return boolean
  4    is
  5    begin
  6      return owa_pattern.match( p_zip_code,
  7                                '[A-Z]{1}\d{1}[A-Z]{1}\d{1}[A-Z]{1}\d{1}',
  8                                'i' );
  9    end is_valid_zip;
 10  begin
 11    if( is_valid_zip( 'A1B2C3' ) )
 12    then
 13      p.l( '1) Match' );
 14    else
 15      p.l( '1) No match' );
 16    end if;
 17    if( is_valid_zip( '12345' ) )
 18    then
 19      p.l( '2) Match' );
 20    else
 21      p.l( '2) No match' );
 22    end if;
 23* end;
SQL> /
1) Match
2) No match

PL/SQL procedure successfully completed.