SQL Server - Where Clause

Where Clause :

                             Where clause is used to filter the rows based on the search condition .

                                     with where clause

                                                * We can retrieve or modify some specific records in the table

                                                * We can delete some specific records in the table

                                                * We cannot insert the records into the table but we can copy the data                                                      from one table to another table

Syntax:   Where < Search Condition >

    The search condition can be any of the following conditions .

                          

                               *  Where with AND condition

                               *  Where with OR condition

                               *  Where with combining  AND & OR conditions etc

                               

Examples :

Write a query to create a table from an existing table

Syntax

                 Select * into <NewTableName> from <OldTableName>

 Ex:

                 Select * into new_emp from emp

In the above case it creates a table new_emp by copying all the rows and columns of the emp table

Create a table from old table without any data in it 

Syntax: 

             Select * into <NTN> from <old-tablename> where <false-condition>

Ex:

             Select * into dummy_emp from emp where 1=2

Create a table from old table only with specified columns

 Select empno,ename into test_emp from emp

Write a query to copy the data from one table to another table

Syntax :

                Insert into <NTN> select * from <OTN> where <Condition>

Ex:  

                 Insert into dummy_emp select * from emp where deptno=10

Write a query create a table with only information of sales department from emp table

Select * into sales_emp from emp where deptno=(select deptno from dept where dname='sales')