Oracle: ORA-00918 Error Message

ORA-00918 Error Message

Learn the cause and how to resolve the ORA-00918 error message in Oracle.

Description

When you encounter an ORA-00918 error, the following error message will appear:

• ORA-00918: column ambiguously defined

Cause

You tried to execute a SQL statement that joined two or more tables, where a column with the same name exists in both tables.

Resolution

The option(s) to resolve this Oracle error are:

Option #1

Prefix the column with the table name and then re-execute the statement.

For example, if you tried to execute the following SQL statement:

SELECT supplier_id, quantity
FROM suppliers
INNER JOIN orders
ON suppliers.supplier_id = orders.supplier_id;

You would receive the following error message:

Since the supplier_id column exists in both the suppliers and orders table, you need to prefix the column with the table name as follows:

SELECT suppliers.supplier_id, quantity
FROM suppliers
INNER JOIN orders
ON suppliers.supplier_id = orders.supplier_id;