MySQL Cookbook

Creating Single-Pick Form Elements from Database Content

Problem

A form needs to present a field that offers the user a set of options but allows only one of them to be selected.

Solution

Use a single-pick list element. These include radio button sets, pop-up menus, and scrolling lists.

Discussion

Single-pick form elements allow you to present multiple choices from which a single option can be selected. Our example involves several sets of single-pick choices:

• The list of colors in the cow_color table. These can be obtained with the following query:

  mysql> SELECT color FROM cow_color ORDER BY color;
  +---------------+
  | color         |
  +---------------+
  | Black         |
  | Black & White |
  | Brown         |
  | Cream         |
  | Red           |
  | Red & White   |
  | See-Through   |
  +---------------+

  Note that some of the colors contain a & character, which is special in HTML. This means they will need HTML-encoding when placed into list elements. (Actually, we’ll perform encoding for all the list elements in the form, but these values illustrate why it’s a good idea to get in that habit.)

• The list of legal figurine sizes in the size column of the cow_order table. The column is represented as an ENUM, so the possible values and the default value can be obtained using SHOW COLUMNS:

  mysql> SHOW COLUMNS FROM cow_order LIKE 'size'\G
  *************************** 1. row ***************************
    Field: size
     Type: enum('small','medium','large')
     Null: YES
      Key:
  Default: medium
    Extra:

• The list of state names and abbreviations. These are available ...