How to fix the 'Ambiguous Column Name' error in SQL

How to fix the 'Ambiguous Column Name' error in SQL

The "ambiguous column name" error is raised in SQL when a query references a column name that is not unique across all the tables in the query.

This can happen if you are joining multiple tables and they have columns with the same name, or if you are using a table alias that conflicts with an existing column name.

Here is an example of a query that will raise an "ambiguous column name" error:

SELECT u.id, o.id
FROM users u
JOIN orders o
ON u.id = o.user_id

In this example, the id column is present in both the users and orders tables.

When the query is executed, the SQL engine will not be able to determine which id column to use, and it will raise an "ambiguous column name" error.

To fix this error, you need to specify which table's id column you want to use in the query.

You can do this by using a table alias and qualifying the column name with the alias.

Here is an example of how to fix the query above:

SELECT u.id AS user_id, o.id AS order_id
FROM users u
JOIN orders o
ON

Conclusion

The "ambiguous column name" error is raised in SQL when a query references a column name that is not unique across all the tables in the query.