SQL WHERE Clause

August 12, 2022

The SQL WHERE clause is used to specify a condition that further is used to fetch the data from a single or by joining multiple tables. When the condition aligned with the where clause is true then it returns the values from the table that matches that particular condition. The WHERE clause should be only when it is necessary.

We see the usage of the WHERE clause is more often with the SELECT statements but the use of the WHERE clause is also with UPDATE or DELETE as well which we will cover in other articles.

Syntax of SQL WHERE Clause –

SELECT column1,column2,column3,...,columnN FROM table_name WHERE condition;

As in the syntax, it can be seen that a condition is aligned with the SQL WHERE clause.

Demo table –

Product Table

Category	Region	City	Country	Customer_ID	Customer_name
Office Supplies	Central	Chicago	United States	SM-20950	Suzanne McNair
Technology	East	New York City	United States	AH-10465	Amy Hunt
Office Supplies	East	New York City	United States	AH-10465	Amy Hunt
Office Supplies	East	Dover	United States	EP-13915	Emily Phan
Office Supplies	East	Dover	United States	EP-13915	Emily Phan
Technology	West	Aurora	United States	TP-21565	Tracy Poddar
Office Supplies	West	Aurora	United States	TP-21565	Tracy Poddar
Office Supplies	East	Long Beach	United States	AR-10825	Anthony Rawles
Office Supplies	West	Pasadena	United States	HA-14920	Helen Andreada
Furniture	West	Pasadena	United States	HA-14920	Helen Andreada

Example – Consider the Product table of the Customer database and fetch records of those Customers who belong to the City of “Chicago” from the Product Table.

SELECT Category,Region,City, [Country/Region],[Customer ID],[Customer Name] FROM [dbo].[Products] WHERE City = 'Chicago';

The output after executing the above statement is as shown –

Category	Region	City	Country	Customer_ID	Customer_name
Office Supplies	Central	Chicago	United States	SM-20950	Suzanne McNair

The following query fetches the Category, Region, City, Country, Customer ID, and Customer Name from the Products table for City with the name Chicago.