SQL -- Aggregate Functions

The following example summarize the numeric results of a column. Here a list of agregate funtions:

MIN	returns the smallest value in a given column
MAX	returns the largest value in a given column
SUM	returns the sum of the numeric values in a given column
AVG	returns the average value of a given column
COUNT	returns the total number of values in a given column
COUNT(*)	returns the number of rows in a table

Here is an example of selecting the maximum price of any item ordered in the item_ordered table.

SELECT MAX(price)

FROM items_ordered;

SQL -- Selecting Distinct

The following example displays a listing of each of the unique (distinct) items from the items_ordered table.

 

Select the distinct items in the items_ordered table. In other words, display a listing of each of the unique items from the items_ordered table.

SELECT DISTINCT item

FROM items_ordered;

 

SQL -- Select Statement

1. Select the customerid, order_date, and item values from the items_ordered table for any items in the item column that start with the letter "S".

SELECT customerid, order_date, item, price

FROM items_ordered

WHERE item LIKE 'S%';