Question 36 :
How will you delete duplicating rows from a base table?
delete from table_name where rowid not in (select max(rowid) from table group by duplicate_values_field_name); or delete duplicate_values_field_name dv from table_name ta where rowid <(select min(rowid) from table_name tb where ta.dv=tb.dv);
Question 37 :
Difference between database triggers and form triggers?
-Data base trigger(DBT) fires when a DML operation is performed on a data base table. Form trigger(FT) Fires when user presses a key or navigates between fields on the screen
-Can be row level or statement level No distinction between row level and statement level.
-Can manipulate data stored in Oracle tables via SQL Can manipulate data in Oracle tables as well as variables in forms.
-Can be fired from any session executing the triggering DML statements. Can be fired only from the form that define the trigger.
-Can cause other database triggers to fire. Can cause other database triggers to fire, but not other form triggers.
Question 38 :
What is a cursor for loop?
Cursor For Loop is a loop where oracle implicitly declares a loop variable, the loop index that of the same record type as the cursor's record.
Question 39 :
How you will avoid duplicating records in a query?
By using DISTINCT
Question 40 :
What is a view ?
A view is stored procedure based on one or more tables, it's a virtual table.