Help with dynamic SQL

Question

Hello,
I have the following function that works ok:
CREATE OR REPLACE FUNCTION Get_Partition_Name (sTable VARCHAR2, iImportIndex INTEGER)
RETURN VARCHAR2 IS
cursor c is select A.partition_name from (select table_name, partition_name,
extractvalue (
dbms_xmlgen.
getxmltype (
'select high_value from all_tab_partitions where table_name='''
|| table_name
|| ''' and table_owner = '''
|| table_owner
|| ''' and partition_name = '''
|| partition_name
|| ''''),
'//text()') import_value from all_tab_partitions) A where table_name = sTable and A.import_value = iImportIndex;
sPartitionName VARCHAR(20);
err_num NUMBER;
BEGIN
open c;
fetch c into sPartitionName;
IF c%ISOPEN THEN
CLOSE c;
END IF;
RETURN sPartitionName;
EXCEPTION
WHEN OTHERS THEN
err_num := SQLCODE;
--save error in log table
LOG.SAVELINE(SQLCODE, SQLERRM);
END Get_Partition_Name;
I am trying to replace the cursor statement with dynamic SQL, something like (see below) but it doesn't work any more; I think I am missing some quotes.
CREATE OR REPLACE FUNCTION Get_Partition_Name (sTable VARCHAR2, iImportIndex INTEGER)
RETURN VARCHAR2 IS
TYPE t1 IS REF CURSOR;
c t1;
sSql VARCHAR2(500);
sPartitionName VARCHAR(20);
err_num NUMBER;
BEGIN
sSql := 'select A.partition_name from (select table_name, partition_name,
extractvalue (
dbms_xmlgen.
getxmltype (
''select high_value from all_tab_partitions where table_name=''''
|| table_name
|| '''' and table_owner = ''''
|| table_owner
|| '''' and partition_name = ''''
|| partition_name
|| ''''''),
''//text()'') import_value from all_tab_partitions) A where table_name = :a and A.import_value = :b';
OPEN c FOR sSql USING sTable, iImportIndex;
fetch c into sPartitionName;
IF c%ISOPEN THEN
CLOSE c;
END IF;
RETURN sPartitionName;
EXCEPTION
WHEN OTHERS THEN
err_num := SQLCODE;
--save error in log table
LOG.SAVELINE(SQLCODE, SQLERRM);
END Get_Partition_Name;
Please advise,
Regards,
M.R.

Answer 1

Assuming the requirement is to find the partition in the supplied table with the supplied high value and the issue is that dba/all_tab_partitions.high_value is a long, one alternative along the same lines as you've done already is as follows. (I've just used a cursor rather than a function for simplicity of demo).
SQL> var r refcursor
SQL> set autoprint on
SQL> declare
  2   ctx dbms_xmlgen.ctxhandle;
  3   v_table_name VARCHAR2(40) := 'LOGMNR_USER$';
  4   v_value      NUMBER       := 100;
  5  begin
  6   ctx := DBMS_XMLGEN.NEWCONTEXT
  7          ('select table_name
  8            ,      partition_name
  9            ,      high_value  hi_val
10            from   dba_tab_partitions
11            where  table_name     = :table_name');
12   dbms_xmlgen.setbindvalue(ctx,'TABLE_NAME',v_table_name);
13   open:r for
14   with x as
15   (select xmltype(dbms_xmlgen.getxml(ctx)) myxml
16    from   dual)
17   select extractvalue(x.object_value,'/ROW/TABLE_NAME') table_name
18   ,      extractvalue(x.object_value,'/ROW/PARTITION_NAME') partition_name
19   ,      extractvalue(x.object_value,'/ROW/HI_VAL') hi_val
20   from   x
21   ,      TABLE(XMLSEQUENCE(EXTRACT(x.myxml,'/ROWSET/ROW'))) x
22   where  extractvalue(x.object_value,'/ROW/HI_VAL') = v_value;
23  end;
24  /
PL/SQL procedure successfully completed.
TABLE_NAME
PARTITION_NAME
HI_VAL
LOGMNR_USER$
P_LESSTHAN100
100
SQL> I'm sure there are other ways as well. Especially with XML functionality, there's normally many ways to skin a cat.