Reference column without table name during table join : Table Alias « Table Joins « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. Table Joins
3. Table Alias

SQL> CREATE TABLE emp
  2  (
  3     cid                NUMBER,
  4     city              VARCHAR2(30),
  5     customer_state             VARCHAR2(40),
  6     country_id                 CHAR(2)
  7  );

Table created.

SQL>
SQL> CREATE TABLE sales(
  2    product_id                NUMBER(6),
  3    cid               NUMBER,
  4    sold             NUMBER(3),
  5    amount                    NUMBER(10,2),
  6    cost                      NUMBER(10,2)
  7  );

Table created.

SQL>
SQL> select product_id, sold, city, customer_state
  2  from   sales, emp
  3  where  sales.cid = emp.cid
  4  and    product_id = 117;

no rows selected

SQL>
SQL>
SQL> drop table emp;

Table dropped.

SQL> drop table sales;

Table dropped.

SQL>