Advanced Queries in Structured Query Language

 

   Some of the advanced Queries in SQL are as Follows: 

   1. SQL ORDER BY Clause:

      Function: This query is used to sort the fetched records in either ascending or 

                        descending order.

     Syntax: 

    Select column1.column2 from tablename Order By Columname ASC|DESC

    Let us understand with the help of an Example  :

   Table1: Customers

                 customerId               customername             customercontact            country

                        1                              Alferd                               Maria                     Germany

                        2                               Ana                                   Ana                        Mexico    

                       4                             Antonio                              Antonio                    Mexico

 Query1: SELECT customername,contactname from customers ORDER BY customername

 Output:

				customername	contactname
				Alferd	Maria
				Ana	Ana
				Antonio	Antonio

  Query2:

  SELECT customername,contactname from customers ORDER BY customername DESC

 

 

  Output:

 


  

				customername	contactname
				Antonio	Antonio
				Ana	Ana
				Alferd	Maria

 

 

 

 2.  SQL MIN() and MAX() Functions:

 

     Syntax: Select  MIN(columnname) from tablename where condition.

 

    Function: This query is used to fetch out the minimum value from the column name

 

    Syntax: Select  MAX(columnname) from tablename where condition.

 

    Function: This query is used to fetch out the maximum value from the column name

 

 

3.SQL COUNT()  Function: 

 

  Syntax : Select  count(columnname) from tablename where condition;

 

  Function: This function is used to return the number of values in a particular column.

 

 

4. SQL AVG()  Function: 

 

    Syntax: Select Avg(columnname)   from tablename where condition;




    Function: This function is used to return the average of the  particular column.







5. SQL SUM()  Function:

 


    Syntax: Select Sum(columnname)   from tablename where condition;




    Function: This function is used to return the sum of a particular column.