Difference between Delete and Truncate

[Aileen_L]

Accidentally, I have deleted the some tables from my database and I am a beginner in oracle,I wanted to restore the deleted tables,now can you tell me some procedure to restore it back.Your suggestion will be appreciated.
Can you tell me what happens when I use delete and truncate.In which scenario it comes in use.

[Praetor]

The Deletecommand is used to remove the tuple from table.Through this command,you can delete the selected rows from the table.You can use Rollback and Commit statement after delete command.

Enter this command to calculate the number of rows

SQL> Select count(*) from my_table;

Delete the selected rows from table,The record which contains the Mem_post as a security would be deleted

SQL>Delete from my_table where Mem_post='Security';

Then enter the first command again to ensure number of rows.

[Katty]

Truncate command:

Truncate command removes all rows from the table at one fire,you can't specify any condition between this statement.You can't rollback the action of this statement.

SQL> Truncate table my_table;

[kelfro]

Hello friend !
As you are new in oracle and you just have deleted a table from your database and willing to restore it back. It is possible to restore it back but it is administrative task.

Before this task,you need to take a physical backup of database.If you have taken any backup before using delete or truncate.You can recover your database but as you mentioned you are a beginner in oracle so go through the sequence of study.