Table Joins Oracle PLSQL

SQL>
SQL>
SQL> create table product(
  2          product_id              integer           primary key
  3          ,price                  number(7,2)
  4          ,description            varchar2(75)
  5          ,onhand                 number(5,0)
  6          ,reorder                number(5,0)
  7          ,supplier_no            integer
  8  );
Table created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (1,2.50,'Oracle',100,20);
1 row created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (2,23.00,'SQL Server',null,null);
1 row created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (3,null,'MySQL',null,null);
1 row created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (4,1.50,'DB2',50,10);
1 row created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (5,10.50,'Java',100,20);
1 row created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (6,45.00,'C++',null,null);
1 row created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (7,19.99,'Javascript',3,5);
1 row created.
SQL> insert into product(product_id, price, description, onhand, reorder)values (8,4.50,'Ruby',null,null);
1 row created.
SQL>
SQL> select * from product;
PRODUCT_ID      PRICE DESCRIPTION                                                                     ONHAND    REORDER SUPPLIER_NO
---------- ---------- --------------------------------------------------------------------------- ---------- ---------- -----------
         1        2.5 Oracle                                                                             100         20
         2         23 SQL Server
         3            MySQL
         4        1.5 DB2                                                                                 50         10
         5       10.5 Java                                                                               100         20
         6         45 C++
         7      19.99 Javascript                                                                           3          5
         8        4.5 Ruby
8 rows selected.
SQL>
SQL> create table product_supplier(
  2             product_id               integer
  3            ,supplier_no              integer
  4            ,price                    number(7,2)
  5            ,primary key (product_id, supplier_no)
  6  );
Table created.
SQL> insert into product_supplier values(1,10,2.25);
1 row created.
SQL> insert into product_supplier values(1,11,2.10);
1 row created.
SQL> insert into product_supplier values(1,12,2.85);
1 row created.
SQL> insert into product_supplier values(2,10,22.25);
1 row created.
SQL> insert into product_supplier values(2,11,22.00);
1 row created.
SQL> insert into product_supplier values(2,12,21.25);
1 row created.
SQL>
SQL> select * from product_supplier;
PRODUCT_ID SUPPLIER_NO      PRICE
---------- ----------- ----------
         1          10       2.25
         1          11        2.1
         1          12       2.85
         2          10      22.25
         2          11         22
         2          12      21.25
6 rows selected.
SQL>
SQL> create table supplier(
  2          supplier_no             integer           primary key
  3          ,supplier_name          varchar2(50)
  4          ,address                varchar(30)
  5          ,city                   varchar(20)
  6          ,state                  varchar2(2)
  7          ,area_code              varchar2(3)
  8          ,phone                  varchar2(8)
  9  );
Table created.
SQL> insert into supplier(supplier_no, supplier_name)values(10,'ABC Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(11,'BCD Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(12,'WWW Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(13,'XYZ Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(14,'R Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(15,'D Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(16,'B Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(17,'W Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(18,'P Gift Supply Co.');
1 row created.
SQL> insert into supplier(supplier_no, supplier_name)values(19,'R Gift Supply Co.');
1 row created.
SQL>
SQL> select * from supplier;
SUPPLIER_NO SUPPLIER_NAME                                      ADDRESS                        CITY         ST ARE PHONE
----------- -------------------------------------------------- ------------------------------ -------------------- -- --- --------
         10 ABC Gift Supply Co.
         11 BCD Gift Supply Co.
         12 WWW Gift Supply Co.
         13 XYZ Gift Supply Co.
         14 R Gift Supply Co.
         15 D Gift Supply Co.
         16 B Gift Supply Co.
         17 W Gift Supply Co.
         18 P Gift Supply Co.
         19 R Gift Supply Co.
10 rows selected.
SQL>
SQL> select supplier_name,
  2          description
  3  from supplier s,product_supplier ps,product p
  4  where s.supplier_no = ps.supplier_no
  5  and ps.product_id = p.product_id;
SUPPLIER_NAME                                      DESCRIPTION
-------------------------------------------------- ---------------------------------------------------------------------------
ABC Gift Supply Co.                                Oracle
BCD Gift Supply Co.                                Oracle
WWW Gift Supply Co.                                Oracle
ABC Gift Supply Co.                                SQL Server
SUPPLIER_NAME                                      DESCRIPTION
-------------------------------------------------- ---------------------------------------------------------------------------
BCD Gift Supply Co.                                SQL Server
WWW Gift Supply Co.                                SQL Server
6 rows selected.
SQL>
SQL> drop table supplier;
Table dropped.
SQL> drop table product_supplier;
Table dropped.
SQL> drop table product;
Table dropped.
SQL> --