SQL SERVER -- Query Basics-- Part-15

Query Basics:-

                                                    Lets see how to pull data from Tables using basic SQL Query

SELECT :-  
                 Used to Retrieve data from the Table OR View

How to Retrieve all the columns from the Table:- 

SELECT * FROM EMP

How to Retrieve Specific(Selected) columns from the Table:- 

SELECT EMPNAME

      ,SAL

      ,LOC

FROM EMP

WHERE :- 
                Where Clause is Used to filter the data based any column.

SELECT *

FROM EMP

WHERE LOC='Bangalore'

GROUP BY :-   

                    Group By Clause is Used to Group the data and perform       Aggregate Operations like Totals and sub totals.

SELECT LOC,COUNT(EMPID) AS EmpCount

FROM EMP

GROUP BY LOC

ORDER BY :-   
                     Order by Clause is Used to Sort the data either in ascending OR Descending order based on any column.

SELECT *

FROM EMP

ORDER BY EMPNAME DESC

SELECT *

FROM EMP

ORDER BY EMPNAME ASC

HAVING :-   
                     Having Clause is Used filter Aggregated Data.

  SELECT LOC,COUNT(EMPID) AS EmpCount

FROM EMP

GROUP BY LOC

HAVING COUNT(EMPID)=1