Values and Subtotals

From SQLZOO
Jump to navigation Jump to search

Get values and Subtotals in one shot.

In this example you are shown how to obtain subtotals in your query, allowing you to easily see SUM results for different elements.

Table 1 shows the result without the subtotals and Table 2 shows the result with subtotals.

Table 1
itemserialnumberprice
Awl110
Awl310
Bowl210
Bowl510
Bowl610
Cowl410
Table 2
itemserialnumberprice
Awl110
Awl310
Awl20
Bowl210
Bowl510
Bowl610
Bowl30
Cowl410
Cowl10
schema:scott
DROP TABLE serial
 CREATE TABLE serial(
  item VARCHAR(20),
  serialnumber INTEGER,
  price INTEGER );
INSERT INTO serial VALUES ('Awl',1,10);
INSERT INTO serial VALUES ('Awl',3,10);
INSERT INTO serial VALUES ('Bowl',2,10);
INSERT INTO serial VALUES ('Bowl',5,10);
INSERT INTO serial VALUES ('Bowl',6,10);
INSERT INTO serial VALUES ('Cowl',4,10);

In this example a UNION is used to make the query show the subtotal results along with the price results and to ensure the subtotals come after the price a COALESCE function is also used.

SELECT item, serialnumber, price 
  FROM(SELECT item, serialnumber, price 
         FROM serial
         UNION
         SELECT item, NULL, SUM(price)
           FROM serial
           GROUP BY item ) t
           ORDER BY item, 
           COALESCE(serialnumber,1E9)