Oracle PL/SQL/Select Query/UNIQUE — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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(нет различий)
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Версия 16:45, 26 мая 2010
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>
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