Question

I have a data stored as comma separated in the database field. Like say in a field colors there are following rows.

red,blue, green
blue, white, purple, pink
yellow, khaki, maroon, orange
gray, lemon, black, brown

Next user has a textbox in a html form, where he enters a colors in a comma separated form. I want to search the database to return records matching his input. For example.

If I enter red, purple, orange, then the query should return three rows because first row has red, second row has purple and third has orange.

I m not getting the way to easier than breaking the user inputs into array and looping through each colors and search the database to get results. Is there any easier way to do this?

Edit

I know storing data in comma separated form is not a good practice but I m working on a updates on application which was made by other programmer. And at this stage I cannot afford to change table structures.

Thanks

Answer 1

1. Of course normalisation is the best approach if it is an option:

   CREATE TABLE colors ( color VARCHAR(6) NOT NULL PRIMARY KEY );
   
   INSERT INTO colors VALUES
     ('red'), ('blue'), ('green'), ('white'), ('purple'), ('pink'),
     ('yellow'), ('khaki'), ('maroon'), ('orange'), ('gray'),
     ('lemon'), ('black'), ('brown');
   
   CREATE TABLE itemColors (
     item_id BIGINT UNSIGNED NOT NULL,
     color   VARCHAR(6)      NOT NULL,
     FOREIGN KEY (item_id) REFERENCES my_table (id),
     FOREIGN KEY (color)   REFERENCES colors   (color)
   );
   
   INSERT INTO itemColors (item_id, color)
     SELECT my_table.id, colors.color
     FROM   my_table JOIN colors ON FIND_IN_SET(colors.color, my_table.colors);
   
   ALTER TABLE my_table DROP COLUMN colors;
   

   Then one would merely need do:

   SELECT *
   FROM   my_table
   WHERE  id IN (
                  SELECT item_id
                  FROM   itemColors
                  WHERE  color IN ('red','purple','orange')
                )
   

2. Otherwise you could build a query (in your application) that uses MySQL’s FIND_IN_SET() function:

   SELECT *
   FROM   my_table
   WHERE  FIND_IN_SET('red',    colors)
       OR FIND_IN_SET('purple', colors)
       OR FIND_IN_SET('orange', colors)