Hi,
I got ” ORA-00918: column ambiguously defined ” error in Oracle SQL .
Details of error are as follows.
ORA-00918: column ambiguously defined
The ORA-00918 error is related with the same column name in the join tables. When you use 2 column with the same name exists in the both tables when join two or more tables, you can get this error.
A column name used in a join exists in more than one table and is thus referenced ambiguously. In a join, any column name that occurs in more than one of the tables must be prefixed by its table name when referenced. The column should be referenced as TABLE.COLUMN or TABLE_ALIAS.COLUMN.
To solve this error, you need to use the Table alias or TABLE_NAME.COLUMN_NAME usage especially in the Table Join as follows.
SQL> SELECT employee_id, first_name,last_name,city, department_name
FROM hr.employees e
JOIN hr.departments d
ON d.department_id = e.department_id
JOIN hr.locations l
ON d.location_id = l.location_id where l.location_id>2400;
EMPLOYEE_ID FIRST_NAME LAST_NAME CITY DEPARTMENT_NAME
----------- -------------------- ------------------------- ------------------------------ ------------------------------
145 John Russell Oxford Sales
146 Karen Partners Oxford Sales
147 Alberto Errazuriz Oxford Sales
148 Gerald
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