CROSS JOIN In SQL

In this article, we will see how to use 'CROSS JOIN In SQL' When each row of Table 1 is merged within each row of Table 2, then it's called a CROSS JOIN or Cartesian Join or in simple words, we can say it like CROSS JOIN always returns the Cartesian product of the sets of the record from (another two or more tables) joined table.

Introduction

In this blog, we will see how to use 'CROSS JOIN In SQL'.

When each row of Table 1 is merged within each row of Table 2, then it's called a CROSS JOIN or Cartesian Join or in simple words, we can say that like CROSS JOIN it always returns the Cartesian product of the sets of the record from (another two or more tables) joined table.

We can write it with a comma-separated table name in order to achieve the same result or we can just write CROSS JOIN just like INNER JOIN without where clause,

SELECT TABLE1.Name, TABLE1.Age, TABLE2.ProjectName,TABLE2.DoA
FROM [EmpTable] AS TABLE1, [Projects] AS TABLE2
OR
SELECT TABLE1.Name, TABLE1.Age, TABLE2.ProjectName, TABLE2.DoA
FROM [EmpTable] AS TABLE1 CROSS JOIN [Projects] AS TABLE2

Let's consider the following two tables,

Table 1 - EmpTable 

 

Table 2 - Projects

Now it's time to see the result. As we already know in CROSS JOIN, each row from Table 1 merged (joins/combined) with all rows of Table 2 (other tables / joined tables ) if Table 1 is having X number of rows and Table 2 having some Y number of rows then the result will be X * Y number of rows.

Hope this will help you.

Thanks.