Why EXECUTE IMMEDIATE is needed here?

Question

I am a SQL Server user and I have a small project to do using Oracle, so I’m trying to understand some of the particularities of Oracle and I reckon that I need some help to

Answer 1

I have modified your code a litle bit and it works as far as logic is concerned. But as exp[lained in earlier posts creating GTT on the fly at run time is not at all is a goood idea.

--- Firstly by dropping the table i.e NO TABLE EXISTS in the DB in AVROY 

SET serveroutput ON;
DECLARE
  table_count INTEGER;
  var_sql     VARCHAR2(1000) := 'create GLOBAL TEMPORARY table TEST (            
hello varchar(1000) NOT NULL)';
BEGIN

EXECUTE IMMEDIATE 'DROP TABLE AVROY.TEST'; --Added the line just to drop the table as per your comments

  SELECT COUNT(*)
  INTO table_count
  FROM all_tables
  WHERE table_name = 'TEST'
  AND OWNER        = 'AVROY';
  IF table_count   = 0 THEN
    EXECUTE IMMEDIATE var_sql;
    dbms_output.put_line('table created');
  ELSE
    INSERT INTO AVROY.test
      (hello
      ) VALUES
      ('hi'
      );
  END IF;
END;

--------------------OUTPUT-----------------------------------------------

anonymous block completed
table created

SELECT COUNT(*)
--  INTO table_count
  FROM all_tables
  WHERE table_name = 'TEST'
  AND OWNER        = 'AVROY';

COUNT(*)
------
1
--------

-- Second option is without DROPPING TABLE


SET serveroutput ON;
DECLARE
  table_count INTEGER;
  var_sql     VARCHAR2(1000) := 'create GLOBAL TEMPORARY table TEST (            
hello varchar(1000) NOT NULL)';
BEGIN

--EXECUTE IMMEDIATE 'DROP TABLE AVROY.TEST';

  SELECT COUNT(*)
  INTO table_count
  FROM all_tables
  WHERE table_name = 'TEST'
  AND OWNER        = 'AVROY';
  IF table_count   = 0 THEN
    EXECUTE IMMEDIATE var_sql;
    dbms_output.put_line('table created');
  ELSE
    INSERT INTO AVROY.test
      (hello
      ) VALUES
      ('hi'
      );
      dbms_output.put_line(SQL%ROWCOUNT||' Rows inserted into the table');
  END IF;
END;

-------------------------------OUTPUT-------------------------------------

anonymous block completed
1 Rows inserted into the table


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