SQL WHERE Clause

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.

  • NOTE – All the strings should be given inside single quotes (‘ ‘). Whereas, numeric values should be given without any quote.

Conditional Operators in WHERE clause –

 

Other SQL topics to check out:

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