TRY -
Approach 1
temp_var := 'ALTER TABLE tablename ADD ("COLUMN_NAME" INTEGER)';
EXECUTE IMMEDIATE (:temp_var );
Approach 2
EXECUTE IMMEDIATE 'ALTER TABLE tablename ADD ("COLUMN_NAME" INTEGER)';
TRY -
Approach 1
temp_var := 'ALTER TABLE tablename ADD ("COLUMN_NAME" INTEGER)';
EXECUTE IMMEDIATE (:temp_var );
Approach 2
EXECUTE IMMEDIATE 'ALTER TABLE tablename ADD ("COLUMN_NAME" INTEGER)';