Question

I’ve been playing around with a few SQL queries trying to get the column name when the field from the row is equal to 1.

My table looks like this:

user  | col 1 | col 2 | col 3 | col 4 |
user1 |    1  |    1  |     0 |    1  |
user2 |    0  |    1  |     1 |    1  |
user3 |    1  |    0  |     0 |    1  |

I’m trying to get each column name to display for when each value is equal to 1.

SELECT ColNames
FROM table
WHERE user1 = 1

Answer 1

As above, you need three tables. One for users, one for items, and one that joins the two. Here’s the structure and queries that I use for a similar function, maintaining user defined mailing lists:

CREATE TABLE `tbl_listmembers` (
`listmem_id` int(11) NOT NULL AUTO_INCREMENT,
`list_id` int(11) NOT NULL,
 `user_id` int(11) NOT NULL,


CREATE TABLE `tbl_lists` (
`list_id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` int(11) NOT NULL,
`list_name` varchar(45) DEFAULT NULL,
`list_description` varchar(250) DEFAULT NULL,


CREATE TABLE `tbl_user_accounts` (
 `user_id` int(11) NOT NULL AUTO_INCREMENT,
 `user_first_name` varchar(45) NOT NULL,
 `user_last_name` varchar(45) NOT NULL,

And the query that pulls up members from a particular list:

SELECT lm.list_id, lm.user_id, ua.user_first_name, ua.user_last_name, ua.user_id
FROM test.tbl_listmembers AS lm 
LEFT JOIN test.tbl_user_accounts AS ua ON (ua.user_id = lm.user_id)
WHERE (lm.list_id = combo_box_selected_listnumber)

Hope that helps.