You mean a single field has multiple values? This means that your design is not normalized. You need to create a many to many table, and stores the id of the row in one column, and the values in another column. One row for each value.
For instance, a table that looks like this:
id | name | date | values
22 | blah | 20040315 | 1:3:5
23 | bleh | 20040322 | 5:2:56
should actually be 2 tables, like this:
id | name | date
22 | blah | 20040315
23 | bleh | 20040322
id | other_tables_id | values
1 | 22 | 1
2 | 22 | 3
3 | 22 | 5
4 | 23 | 5
5 | 23 | 2
6 | 23 | 56
Do a join to get your data, and you are set.
