Why do we use WHERE 1=1 in the SQL Script?

A lot of people ask us why we use WHERE 1=1 in the SQL scripts. Here, we explain why we use WHERE 1=1 in the SQL Scripts. If you are a novice, you can also get knowledge of SQL Scripts.

The below script creates a customer table with sample records.

CREATE TABLE Customer
(
       ID int,
       [Name] VARCHAR(50),
       Loation VARCHAR(50)
)
GO
INSERT INTO Customer
SELECT 1,'Rajendra','India' UNION ALL
SELECT 2,'Manoj','USA' UNION ALL
SELECT 3,'Kashish','Jaipur'
Go

Suppose you write a dynamic SQL so that if the input value is null, we do not need to compare.

DECLARE @ID INT, @Location VARCHAR(50), @sql NVARCHAR(100)
SET @Location='India'
SET @sql = 'Select * from Customer where 1=1'
IF @Location<>''
       set @sql += ' and Location='''+@Location +''''
exec sp_executesql @sql 

If you do not enter the parameter value, the query returns all rows because it does not include the location condition due to the false if condition.

DECLARE @ID INT, @Location VARCHAR(50), @sql NVARCHAR(100)
SET @Location=''
SET @sql = 'Select * from Customer where 1=1'
IF @Location<>''
       set @sql += ' and Location='''+@Location +''''
exec sp_executesql @sql