Question

If I have a table:

CREATE TABLE Kids (
    kid_id int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
    kid_name varchar(45) NOT NULL,
    kid_favcolors (text) NULL,
    PRIMARY_KEY(kid_id)
    )

and I have a table:

CREATE TABLE Colors (
    color_id int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
    color_name varchar(45) NOT NULL,
    PRIMARY_KEY(color_id)
)

With rows that reference favorite colors via comma separated ids:

INSERT INTO Kids(kid_name, kid_favcolors) VALUES('Joe','1,2,3,4,5');
INSERT INTO Kids(kid_name, kid_favcolors) VALUES('Mary','1,2,3');

How would I create a statement that would return each entry in the Kid database with the Kid_name and the color_name of all of the ids referenced in the kid_favcolors column.

For example:

COLORS:

color_id    color_name
1           yellow
2           green
3           blue
4           purple
5           red
6           brown
7           black

KIDS:

kid_id      kid_name    kid_favcolors
1           Joe         1,2,3,4,5
2           Mary        1,2,3

and I want to retrieve

kid_id      kid_name    favorite_colors
1           Joe         yellow, green, blue, purple, red
2           Mary        yellow, green, blue

The queries are being executed on existing data and database structure. If there is no feasible solution, rearranging the structure of the data is possible but I assume would add a considerable amount of time to the solution. Either way, would like some help.

I am able to retrieve the colors from the database using:

SELECT STUFF((SELECT ', ' + color_name FROM colors WHERE color_id IN (1,2,3,4,5) FOR XML PATH('')),1, 2, '') AS colors

        colors
1       yellow, green, blue, purple, red

But when I try a more complex query I can’t seem to find a way to incorporate the above statement by pulling the ids from the Kids table.

SELECT kids.kid_id, kids.kid_name, favorite_colors FROM kids JOIN colors ON colors.id IN kids.kid_favcolors as favorite_colors

While it looks like it could work to me, not working. Not sure if I’m way off or really close.

Answer 1

I have worked up a solution; though it’s not pretty, it works.

SELECT 
  kid_id,
  kid_name, 
  (SELECT STUFF(
     (SELECT ', '+color_name FROM colors WHERE color_id in 
        (SELECT s from SplitString(kid_favcolors,',')) 
     FOR XML PATH(''))
   ,1,2,'')) AS favorite_colors 
FROM KIDS

kid_id      kid_name    favorite_colors
1           Joe         yellow, green, blue, purple, red
2           Mary        yellow, green, blue

I have talked to them about reworking the DB and implementing a current administration site to accommodate the changes

Split String function I used:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
create function [dbo].[SplitString] 
(
    @str nvarchar(4000), 
    @separator char(1)
)
returns table
AS
return (
    with tokens(p, a, b) AS (
        select 
            1, 
            1, 
            charindex(@separator, @str)
        union all
        select
            p + 1, 
            b + 1, 
            charindex(@separator, @str, b + 1)
        from tokens
        where b > 0
    )
    select
        p-1 zeroBasedOccurance,
        substring(
            @str, 
            a, 
            case when b > 0 then b-a ELSE 4000 end) 
        AS s
    from tokens
  )