Run sql stored as value in a table in oracle and return recordset in SSRS report

Question

I've a query that creates a SQL Statement as a field. I want to execute this statement and return the recordset in SSRS report.

select 'select '||FILE_ID||' FILE_ID,'||
ltrim(sys_connect_by_path('REC_FLD_'||FIELD_NUMBER||' "'||FIELD_NAME||'"',','),',')||
' from RESPONSE_DETAILS where FILE_ID=' ||FILE_ID||';'
from (select t.*,count(*) over (partition by FILE_ID) cnt from RESPONSE_METADATA t)
where cnt=FIELD_NUMBER start with FIELD_NUMBER=1 
connect by prior FILE_ID=FILE_ID and prior FIELD_NUMBER=FIELD_NUMBER-1

This generates a SQL stetment - however I want this SQL to be executed.

This is an extension of this question.

I've tried to use execute immediate , cursors, dbms_sql but it does not produce output. Using it on toad. All it says is "PL/SQL procedure successfully completed"

Using the following

Declare 
  sql_stmt  VARCHAR2(3000);
  l_cursor  SYS_REFCURSOR;
  TYPE RefCurTyp    IS REF CURSOR;
  v_cursor          RefCurTyp;
  CURSOR c1 is
    select 'select '||FILE_ID||' FILE_ID,'||
    ltrim(sys_connect_by_path('REC_FLD_'||FIELD_NUMBER||' "'||FIELD_NAME||'"',','),',')||
    ' from RESPONSE_DETAILS where FILE_ID=' ||FILE_ID||';'
    from (select t.*,count(*) over (partition by FILE_ID) cnt from RESPONSE_METADATA t)
    where cnt=FIELD_NUMBER start with FIELD_NUMBER=1 
    connect by prior FILE_ID=FILE_ID and prior FIELD_NUMBER=FIELD_NUMBER-1;
BEGIN
  open c1;
  FETCH C1 into sql_stmt ;
  dbms_output.put_line(sql_stmt);
  close c1; 
  EXECUTE IMMEDIATE sql_stmt;
  open v_cursor for sql_stmt;
  return l_cursor;
  close l_cursor ;
END;

Answer 1

An anonymous PL/SQL block cannot return any data to the caller. If you want to return a SYS_REFCURSOR to the calling application, you would need to create a function (or a procedure). For example

CREATE OR REPLACE FUNCTION get_results
  RETURN sys_refcursor
IS
  l_sql_stmt  VARCHAR2(3000);
  l_cursor    SYS_REFCURSOR;
BEGIN
  select 'select '||FILE_ID||' FILE_ID,'||
          ltrim(sys_connect_by_path('REC_FLD_'||FIELD_NUMBER||' "'||FIELD_NAME||'"',','),',')||
         ' from RESPONSE_DETAILS where FILE_ID = ' ||FILE_ID||';'
    into l_sql_stmt
    from (select t.*,count(*) over (partition by FILE_ID) cnt from RESPONSE_METADATA t)
   where cnt=FIELD_NUMBER 
   start with FIELD_NUMBER=1 
 connect by prior FILE_ID=FILE_ID 
        and prior FIELD_NUMBER=FIELD_NUMBER-1;

  dbms_output.put_line(l_sql_stmt);
  open l_cursor for sql_stmt;
  return l_cursor;
END;

I am assuming from your code that you expect your SELECT statement to return a single SQL statement-- your code is fetching only one row from a query that potentially returns multiple SQL statements. I'm assuming that you only fetch one because you only expect the SELECT statement to return one row. Otherwise, since your query lacks an ORDER BY, you are executing arbitrarily one of N SQL statements that your code is generating.

If you are regularly going to be calling this method, you would almost certainly want to use bind variables in your dynamic SQL statement for the file_id rather than generating non-sharable SQL statements. I haven't made that change here.

There is another StackOverflow thread on calling a stored function returning a sys_refcursor from SSRS.