MySQL Count presence of multiple values in same column

Question

I have a single table called Customers with a CustID column and another column called ProductCode. There are 33 possible products (numbered 1 to 33) and each customer can have any combination of products. There is a single row for each customer and all of the products that each customer has are shown in the ProductCode column with a space in between ie:

CUSTID     PRODUCTCODE  
------     -----------

001        3 12 18 22 32  
002        9 6 18 36  
003        3 6 7 26  
004        9 11 33   
005        6 21 28 29 30 31  
006        1 3 6 21 30 31  

I need to be able to do a count of each product and add a text description of the code:

ProdCode    Description       Count  
~~~~~~~~    ~~~~~~~~~~~       ~~~~~  
1           Lawnmower         1  
3           Spade             3  
6           Clippers          4  
etc

Thanks!

Answer 1

Never, never, never store multiple values in one column!

As you see now this will only result in problems. Please normalize your DB structure with an additional table

customer_products
CUSTID     PRODUCTCODE  
------     -----------
001        3
001        12
001        18
---
002        9
002        6
...

Then you can remove the PRODUCTCODE column from your customer table.

Answer 2

One solution can be to change you schema to have two columns:-

1) Customer Id 2) Product Id

So data would look something like this:-

cust_id| product_id

001    | 3
001    | 6
002    | 9

... ...

So now in mysql query you can use query like

Select product_id,count(*) as num_products from table_name group by product_id;

Hope this helps.

If you cant alter your schema, then you have to fetch the data and in your scripting language you have to process it as you want.

Answer 3

Try this:

CREATE TABLE ord (custid VARCHAR(3), productcode VARCHAR(40));

INSERT INTO ord VALUES ('001', '3 12 18 22 32');
INSERT INTO ord VALUES ('002', '9 6 18 36');
INSERT INTO ord VALUES ('003', '3 6 7 26');
INSERT INTO ord VALUES ('004', '9 11 33');
INSERT INTO ord VALUES ('005', '6 21 28 29 30 31');
INSERT INTO ord VALUES ('006', '1 3 6 21 30 31');

CREATE TABLE products (code VARCHAR(2));

INSERT INTO products VALUES ('3');
INSERT INTO products VALUES ('12');
INSERT INTO products VALUES ('18');
INSERT INTO products VALUES ('22');
INSERT INTO products VALUES ('32');
INSERT INTO products VALUES ('9');
INSERT INTO products VALUES ('6');
INSERT INTO products VALUES ('31');

CREATE TABLE ord_prod (code VARCHAR(2), count_of_products INT) AS
  SELECT p.code, 
        (SELECT COUNT(1)
           FROM ord o
         WHERE INSTR(CONCAT(' ', o.productcode, ' '), CONCAT(' ', p.code, ' ')) > 0) AS count_of_products
    FROM products p;

Check at SQLFiddle: http://sqlfiddle.com/#!2/a7f94/1

Change your types as you need, add the rest of the products, add the description etc.