Sorting by Multiple Columns

It is often necessary to sort data by more than one column. For example, if you are displaying an employee list, you might want to display it sorted by last name and first name (first by last name, and then within each last name sort by first name). This would be useful if there are multiple employees with the same last name.

To sort by multiple columns, simply specify the column names separated by commas (just as you do when you are selecting multiple columns).

The following code retrieves three columns and sorts the results by two of them—first by price and then by name.

SELECT prod_id, prod_price, prod_name
FROM Products
ORDER BY prod_price, prod_name;

prod_id     prod_price     prod_name
-------     ----------     --------------------
BNBG02      3.4900         Bird bean bag toy
BNBG01      3.4900         Fish bean bag toy
BNBG03      3.4900         Rabbit bean bag toy
RGAN01      4.9900         Raggedy Ann
BR01        5.9900         8 inch teddy bear
BR02        8.9900         12 inch teddy bear
BR03        11.9900        18 inch teddy bear

It is important to understand that when you are sorting by multiple columns, the sort sequence is exactly as specified. In other words, using the output in the example above, the products are sorted by the prod_name column only (if the prod_price value is the same). If all the values in the prod_price column had been unique, no data would have been sorted by prod_name.

..................Content has been hidden....................

You can't read the all page of ebook, please click here login for view all page.
Reset
3.141.35.60