SQL Self JOIN
SQL Self JOIN
A self JOIN is a regular join, but the table is joined with itself.
Self JOIN Syntax
SELECT column_name(s)
FROM table1 T1, table1 T2
WHERE condition;
Demo Database
In this tutorial we will use the well-known Northwind sample database.
Below is a selection from the "Customers" table:

SQL Self JOIN Example
The following SQL statement matches customers that are from the same city:
SELECT A.CustomerName AS CustomerName1, B.CustomerName AS CustomerName2, A.City
FROM Customers A, Customers B
WHERE A.CustomerID <> B.CustomerID
AND A.City = B.City
ORDER BY A.City;
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