Difference between Delete & Truncate

Differentiate between DELETE and TRUNCATE

Sr. No	Truncate	Delete
1	It cannot be rolled back	It can be
2	Truncate keeps the lock on table	Delete keeps the lock on each row.
3	Truncate resets the counter of the Identity column	It doesn’t do so
4	Trigger is not fired in Truncate	Trigger happens in table.

Join Clause

Join means combining two or more tables in a database.

Emp_id	Emp_name
1	Suryagroops
2	Suresh
3	Mayank dixit
4	Suryagroops
5	Ramesh
6	Ramesh
7	Shalini
8	Sushil

                                                                  

                                                                     tbl_emp

Cust_id	Cust_Salary
7	3500
8	2500
9	4566

                                                                   

                                                                      tbl_cust

SELECT        Cust_id, Cust_Salary, Emp_Name 

FROM tbl_cust, tbl_emp

WHERE tbl_cust.Cust_id = tbl_emp.Emp_id

Or

SELECT        tbl_cust.Cust_ID, tbl_cust.Cust_Name, tbl_emp.emp_name

FROM            tbl_cust INNER JOIN

                         tbl_emp ON tbl_cust.Cust_ID = tbl_emp.emp_id

Result-

Cust_id	Emp_Name	Cust_Salary
7	Shalini	3500
8	Sushil	2500

TOP Clause

Emp_id	Emp_name
1	Suryagroops
2	Suresh
3	Mayank dixit
4	Suryagroops
5	Ramesh
6	Ramesh
7	Shalini
8	Sushil

                                                                 tbl_emp

TOP Clause

SELECT TOP (3) Emp_Name FROM tbl_emp

Result-

Emp_id	Emp_name
1	Suryagroops
2	Suresh
3	Mayank dixit