The following query counts and displays the total number
of rows in the stock table. Figure 1. Query
SELECT COUNT(*) FROM stock;
Figure 2. Query
result
(count(*))
73
The following query includes a WHERE clause to count specific
rows in the stock table, in this case, only those rows that
have a manu_code of SHM. Figure 3. Query
SELECT COUNT (*) FROM stock WHERE manu_code = 'SHM';
Figure 4. Query result
(count(*))
17
By including the keyword DISTINCT (or its synonym UNIQUE)
and a column name in the following query, you can tally the number
of different manufacturer codes in the stock table. Figure 5. Query