Question

I have been challenged on selecting on different tables based on a parameter.
My question will be pretty much similar to this, but here is my case:

Say I have a parameter list from the front end [1,2,3,4]

And based on this parameter, how can I do select on the different tables on an sql?

In Java, I can do:

StringBuffer sql = new StringBuffer();
if ( parameter == 1)
    sql.append("Select * from TABLEA");
else if  ( parameter == 2)
    sql.append("Select * from TABLEB");
else if  ( parameter == 3)
    sql.append("Select * from TABLEC");
else if  ( parameter == 4)
    sql.append("Select * from TABLED");

How can I do this on SQL itself?

Answer 1

In Oracle PLSQL, you can do it somewhat like this:

PROCEDURE TEST(
        o_retcd OUT NUMBER,
        o_errmsg OUT VARCHAR2,
        o_currStatus IN OUT SYS_REFCURSOR,
        i_type IN VARRAY --your parameters
              ) 
BEGIN

FOR i IN i_type.FIRST..i_type.LAST
    LOOP
         if i_type(i) = 1 then
          OPEN o_currStatus FOR
            select * from TABLEA;
         elsif i_type(i) = 2 then
          OPEN o_currStatus FOR
            select * from TABLEB;
         elsif i_type(i) = 3 then
          OPEN o_currStatus FOR
            select * from TABLEC;
         elsif i_type(i) = 4 then
          OPEN o_currStatus FOR
            select * from TABLED;
         end if;
    END LOOP;

  EXCEPTION
 --Exception handling
  WHEN OTHERS THEN
      o_retcd := 100;

END;