Question

I have a typical table, e.g.

id(int) name(varchar) address(varchar) date(datetime)

I also have a table that references validation functions for each one, e.g.

id(int) function(varchar) fail_message(varchar)
   1    email             Please enter a valid email address
   2    required          This field can not be left blank

I’d like to be able to associate each column from the first table with one or more of these validators.

The only way I can think of doing this is to stuff the ids into the column names e.g. (column name: email;1;2) and keep track of it through PHP, but that seems very messy.

Is there a good way to do this with relational databases? Would a NoSQL implementation suit this problem better?

Answer 1

Similar to what Dan said, a relatively easy way to implement an association in sql would be to do the following:

id(int) function_id(int) col_name(varchar)
1       1                address
2       1                second_address
3       2                address
4       2                name

And then when you want to do the failure check, use the above table to link the error message to the column name (e.g. ‘select function_id from above_table where col_name=”address”‘) and then query the failure table. These tables could subsequently be combined using a view with a join so that a single query would suffice.

Hope this helps.