Dynamisk krydsfaneforespørgsel i Oracle

Du kan bruge dynamiske markører til at udføre dynamisk SQL kompileret fra en VARCHAR2-variabel:

DECLARE 
       w_sql             VARCHAR2 (4000);
       cursor_           INTEGER;
       v_f1    NUMBER (6);
       v_f2    NUMBER (2);
       v_some_value_2_filter_4    NUMBER (2);
       rc      INTEGER         DEFAULT 0;
BEGIN
        -- join as many tables as you need and construct your where clause
        w_sql :='SELECT f1, f2 from TABLE1 t1, TABLE2 t2, ... WHERE t1.f1 =' || v_some_value_2_filter_4 ; 

       -- Open your cursor
       cursor_ := DBMS_SQL.open_cursor;
       DBMS_SQL.parse (cursor_, w_sql, 1);
       DBMS_SQL.define_column (cursor_, 1, v_f1);
       DBMS_SQL.define_column (cursor_, 2, v_f2);
      -- execute your SQL
       rc := DBMS_SQL.EXECUTE (cursor_);

       WHILE DBMS_SQL.fetch_rows (cursor_) > 0
       LOOP
          -- get values from record columns
          DBMS_SQL.COLUMN_VALUE (cursor_, 1, v_f1);
          DBMS_SQL.COLUMN_VALUE (cursor_, 2, v_f2);

          -- do what you need with v_f1 and v_f2 variables

       END LOOP;

END;

Eller du kan bruge udfør omgående , nemmere at implementere, hvis du blot skal kontrollere en værdi eller udføre og indsætte/opdatere/slette forespørgsel

    w_sql :='select f1 from table where f1 = :variable';
    execute immediate w_sql into v_f1 using 'valor1'

Her mere info om dynamiske markører:http://docs. oracle.com/cd/B10500_01/appdev.920/a96590/adg09dyn.htm