Using REPLACE string function with TRIM (Oracle/PLSQL)

Question

I have a problem with a 3rd party product I use which handles external XML files. It causes the database to crash as a result of not being able to parse ampersands correctly (they're not escaped).

If I was to do this via SQLPlus I'd simply use 'SET DEFINE OFF' or 'SET ESCAPE ON' or both!

However, this process calls a function from a package.

Part of the body of the package is as follows:

CURSOR extractxml_c
      IS
       SELECT TRIM( extractvalue(column_value, '/TARLROW/HUSID'))     husid,
              TRIM( extractvalue(column_value, '/TARLROW/UKPRN'))     ukprn,
              TRIM( extractvalue(column_value, '/TARLROW/NUMHUS'))    numhus,
              TRIM( extractvalue(column_value, '/TARLROW/CAMPID'))    campid,
              TRIM( extractvalue(column_value, '/TARLROW/NAMECAT'))   namecat,
              TRIM( extractvalue(column_value, '/TARLROW/COURSEAIM')) courseaim,
              TRIM( extractvalue(column_value, '/TARLROW/CTITLE'))    ctitle,
              TRIM( extractvalue(column_value, '/TARLROW/OWNSTU'))    ownstu,
              TRIM( extractvalue(column_value, '/TARLROW/STATUS') )   status,
              TRIM( extractvalue(column_value, '/TARLROW/YEAR'))      year,
              TRIM( extractvalue(column_value, '/TARLROW/QUALENT2'))  qualent2,
              TRIM( extractvalue(column_value, '/TARLROW/COMDATE'))   comdate,
              TRIM( extractvalue(column_value, '/TARLROW/POSTCODE'))  postcode,
              TRIM( extractvalue(column_value, '/TARLROW/ETHNIC'))    ethnic,
              TRIM( extractvalue(column_value, '/TARLROW/DOMICILE'))  domicile,
              TRIM( extractvalue(column_value, '/TARLROW/YRLLINST') ) yrllinst,
              TRIM( extractvalue(column_value, '/TARLROW/UCASAPPID')) ucasappid,
              TRIM( extractvalue(column_value, '/TARLROW/OWNINST'))   owninst,
              TRIM( extractvalue(column_value, '/TARLROW/TTCID') )    ttcid,
              TRIM( extractvalue(column_value, '/TARLROW/QUALENT3'))  qualent3,
              NULL                                                    pidm,
              p_cohort                                                chrt_code,
              p_term_code                                             term_code,
              USER                                                    user_id,
              SYSDATE                                                 activity_date,
              'Banner: ESC_HST_CHRT_HINTAR_XML'                       data_origin,
              NULL                                                    surrogate_id,
              NULL                                                    version,
              NULL                                                    vpdi_code,
              gkkpsql.API_RetrieveRunSequence                         run_seq
        FROM TABLE(XMLSequence( l_xmltype.extract('/TARLREPORT/TARLROWS/TARLROW'))) ;

I'd like to replace the ampersand characters pulled from the XML file using the replace function at the CTITLE section in the above code.

Something like this:

SELECT REPLACE('&' , '|| chr(38) || ') 

However, I can't seem to get the syntax correct. On package compilation I keep getting missing right parenthesis errors.

I've used:

TRIM( extractvalue(column_value, (REPLACE('&' , '|| chr(38) || ') '/TARLROW/CTITLE'))    ctitle,

and

REPLACE('&' , '|| chr(38) || ') TRIM( extractvalue(column_value, '/TARLROW/CTITLE'))    ctitle,

and neither are working.

Any ideas how I'd replace characters pulled from a TRIM( extractvalue ) string function?

TIA

Answer 1

REPLACE takes three arguments; the optional third one is the replacement string. The first is the original string that you want to transform. So I think you want:

REPLACE(TRIM(extractvalue(column_value, '/TARLROW/CTITLE')),
  '&', chr(38)) ctitle

You don't need the concatenation characters (||) as far as I can tell, unless you're doing something else with this later. The REPLACE and TRIM can go in either order, but one needs to be inside the other.

Not sure what you mean about it causing the database to cash though. This is just a string. It's only treated as a substitution variable if you're using the ampersand in an SQL*Plus command. And your final string will still end up with an ampersand in it. It sounds like you're trying to solve the wrong problem.