WHERE clause in SQL with GROUP BY

WHERE Clause in SQL with GROUP BY

WHERE clause in SQL with GROUP BY is used to extract only those records that fulfil a specified condition. Condition on any dimension or fields available within a Table.

Where clause is very useful and powerful command used in SQL query to extract data from huge Sample of data. It is used in SELECT command of SQL.

Below we will go through the normal where clause command syntax and with examples and then we will look how GROUP BY command can be applied on WHERE clause

WHERE Syntax:

SELECT 
     column1, column2, ...
FROM 
     table_name
WHERE 
     condition;

Example #1: WHERE condition on one column

Lets Take example to Filter on Product_Category equal to Furniture

SELECT 
      *
FROM
     [dbo].[Customers_Tbl]
WHERE
     [Product_Category] = 'Furniture'

Result:

Example #2: WHERE clause for two condition using Logical Function “AND”

Filter on Furniture which have Margin greater then 70%. In this example we are applying WHERE clause for two condition using Logical Function “AND”

SELECT
       [Product_Category], Region,[Product_Base_Margin]
FROM
      [dbo].[Customers_Tbl]
WHERE
       ([Product_Category] = 'Furniture') 
       AND 
       ([Product_Base_Margin] > 0.70

Result:

GROUP BY

Now lets understand Where clause in SQL with GROUP BY

GROUP BY is the command which used to make the output in aggregated way.

The GROUP BY clause arrange the rows members by groups (It is like a Pivot to grouping columns member to see aggregated value). The groups are determined by the columns that you specify in the GROUP BY clause.

Syntax:

SELECT
    select_list
FROM
    table_name
WHERE Condition
GROUP BY
    column_name1,
    column_name2, ..

Example #1: Query to extract data from table with group by Clause

Below Query Product_Category is appear only For individual Product_Container

SELECT
       Product_Category, Product_Container
FROM
       [dbo].[Customers_Tbl]
WHERE
      ([Product_Category] = 'Furniture')  
      OR 
      ([Product_Category] = 'Office supplies')
GROUP BY 
       Product_Category, Product_Container

Result:

Example #2: GROUP BY clause and aggregate functions without WHERE clause

b) SQL Server GROUP BY clause and aggregate functions without WHERE clause

SELECT
    [Order Priority], Sum([Order Quantity]) as order_Quantity
FROM
    [dbo].[Orders_Tbl]
GROUP BY
    [Order Priority]

Result: Here Order quantity is summed up by order Priority