Mysql – How to add two count(*) results together on two different tables

countmysqlsum

I have two tables: Toys and Games.

+--------------------+------------------+
| Field              | Type             |
+--------------------+------------------+
| toy_id             | int(10) unsigned |
| little_kid_id      | int(10) unsigned |
+--------------------+------------------+

+--------------------+------------------+
| Field              | Type             |
+--------------------+------------------+
| game_id            | int(10) unsigned |
| little_kid1        | int(10) unsigned |
| little_kid2        | int(10) unsigned |
| little_kid3        | int(10) unsigned |
+--------------------+------------------+

A little kid can have multiple toys.
A little kid can be participating in multiple games at once.

I want a query that will give me the total number of toys + games that a little_kid is involved with.

Basically, I want the sum of these two queries:

SELECT COUNT(*) FROM Toys WHERE little_kid_id = 900;
SELECT COUNT(*) from Games WHERE little_kid1 = 900 
                              OR little_kid2 = 900 
                              OR little_kid3 = 900;

Is it possible to get this in a single SQL query? Obviously, I can sum them programmatically, but that's less desirable.

(I realize that the contrived example makes the schema look ineffecient. Let's assume that we can't change the schema.)

Best Solution

Wrap them up and use subqueries:

SELECT
(SELECT COUNT(*) FROM Toys WHERE little_kid_id = 900)+
(SELECT COUNT(*) from Games WHERE little_kid1 = 900 
                              OR little_kid2 = 900 
                              OR little_kid3 = 900)
AS SumCount

Voila!