SQL
COUNT
Another arithmetic function is COUNT. This
allows us to COUNT up the number of row in a certain table. The syntax is,
SELECT
COUNT("column_name")
FROM "table_name"
For example, if we want to find the number of store entries in our table,
Table Store_Information
| store_name |
Sales |
Date |
| Los Angeles |
$1500 |
Jan-05-1999 |
| San Diego |
$250 |
Jan-07-1999 |
| Los Angeles |
$300 |
Jan-08-1999 |
| Boston |
$700 |
Jan-08-1999 |
SELECT
COUNT(store_name)
FROM Store_Information
Result:
Count(store_name)
4
COUNT and DISTINCT can
be used together in a statement to fetch the number of distinct entries in a
table. For example, if we want to find out the number of distinct stores, we'd
type,
SELECT
COUNT(DISTINCT store_name)
FROM Store_Information
Result:
Count(DISTINCT store_name)
3
|
|
|
|
