count(*) - count(onhand) : COUNT « Aggregate Functions « Oracle PL / SQL

count(*) - count(onhand)

  

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> -- product Table Inserts:
SQL> insert into product(product_id, price, description, onhand, reorder)values (1,2.50,'Happy Birthday',100,20);

1 row created.

SQL> insert into product(product_id, price, description, onhand, reorder)values (2,23.00,'Happy Birthday',null,null);

1 row created.

SQL> insert into product(product_id, price, description, onhand, reorder)values (3,null,'Happy New Year',null,null);

1 row created.

SQL> insert into product(product_id, price, description, onhand, reorder)values (4,1.50,'Happy New Year',50,10);

1 row created.

SQL>
SQL>
SQL> select count(*) - count(onhand) from product;

COUNT(*)-COUNT(ONHAND)
----------------------
                     2

1 row selected.

SQL>
SQL> drop table product;

Table dropped.

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