Oracle PL/SQL/Select Query/UNIQUE

UNIQUE / DISTINCT

   <source lang="sql">

SQL> SQL> CREATE TABLE purchase (

 2       product_name  VARCHAR2(25),
 3       quantity      NUMBER(4,2),
 4       purchase_date DATE,
 5       salesperson   VARCHAR2(3)
 6       );

Table created. SQL> SQL> INSERT INTO purchase VALUES ("A", 1, "14-JUL-03", "CA"); 1 row created. SQL> INSERT INTO purchase VALUES ("B", 75, "14-JUL-03", "BB"); 1 row created. SQL> INSERT INTO purchase VALUES ("C", 2, "14-JUL-03", "GA"); 1 row created. SQL> INSERT INTO purchase VALUES ("D", 8, "15-JUL-03", "GA"); 1 row created. SQL> INSERT INTO purchase VALUES ("A", 20, "15-JUL-03", "LB"); 1 row created. SQL> INSERT INTO purchase VALUES ("B", 2, "16-JUL-03", "CA"); 1 row created. SQL> INSERT INTO purchase VALUES ("C", 25, "16-JUL-03", "LB"); 1 row created. SQL> INSERT INTO purchase VALUES ("D", 2, "17-JUL-03", "BB"); 1 row created. SQL> SQL> SELECT UNIQUE product_name

 2  FROM          purchase
 3  ORDER BY      product_name;

PRODUCT_NAME

---

A B C D 4 rows selected. SQL> SQL> SELECT Distinct product_name

 2  FROM          purchase
 3  ORDER BY      product_name;

PRODUCT_NAME

---

A B C D 4 rows selected. SQL> SQL> SQL> DROP TABLE purchase; Table dropped. SQL>

</source>