What is the correct way to get the content of a varchar field in pgsql's source code

[Felix.徐 <ygnhzeus@xxxxxxxxx>]

Hi all,

I've learnt from the source code to open a table and scan it, like this:

Relation qma = try_relation_open(qmappersta, AccessShareLock);

  if(qma!=NULL){

    HeapScanDesc scan= heap_beginscan(qma,SnapshotNow,0,NULL);

  HeapTuple tup;

TupleDesc tupDesc= RelationGetDescr(qma);

    Datum   *values;

  bool *nulls;

    int value1;

    char value2;

    while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL){

        heap_deform_tuple(tup,tupDesc,values, nulls);

        /* int values can be retrieved easily */

        value1=values[0];

        /* how to retrieve the content of a varchar field here? */

        /* What I've tried: */

        value2=VARDATA_ANY(values[2]);

        /* But value2 seems to be incorrect

           if the original data is "abcd", then I will get "abcd2" here(in most cases, a "2" is appended to the data...), I'm wondering  how to get the data properly...

           I've also tried VARDATA macro and encountered with the same problem.

        */

    }

  }

Thanks!