What are the main differences between trancate and Delete?
And is "select" command is DML or DDL?

Thanks guys but i have one query, if i have some null values and some empty string in the table and if i execute select * from from table. whether it will print fields having null and empty string ?...

Can anyone explain me what are the main difference between a null value and blank value in database. It important please help me out. thank you.

Thank you!! :)

Can we put only subject.marks in place sum(marks)...
And one more thing can you please ellaborate how this query going to work, i mean in sub query it fetch one record or it going to fetch no. of...

Thanks for your reply...
i guess it going to work...

no one can help me out...in this forum

Hi i want need to fetch sec highest marks from given tables.
my database design is like:
My database design:
Table 1:

Student table
(PK)Stud_id, Stud_name

Table 2:

Hi,
I just want to retrieve name of the employees who have two or more than two email_id in employee table. pls help me out..

yes i too thinking of trigger " after inserting in salary". but was not too sure...

Anuone help on it...

Ya with the same Emp_id it will be ok but i wanta dd new Emp_id in sec table..
just want give more info like:

Emp table
Emp_id Emp_name
1 ABC
2 EFG

Salary table

i dont want to fetch the records i just want to insert new rec in sec table's field so when i enter new Emp_id in salary table then this Emp_id should also be reflected in first table.

There are two tables:
1) Emp table with fields.
Emp_id, Emp_name,Dept.
2) Salary table with fields.
Emp_id, Salary.

I want to insert new record in salary table, if i insert rec in salary table...

i want to insert new row in second table and this table connected to first table.
How can i do that?