PHP MySQL combine cells from different row with same value

Question

I have a database that has id numbers, names, class period, and teacher name. Each row includes a student's id, name, period, and teacher which means that there are multiple rows for each student. That's not my problem. My problem is that some classes have two teachers listed...which means there are two separate rows for 1 class period, one for each teacher. Unfortunately I have no control over the formatting of the data since it's exported from a system that doesn't have a lot of formatting options.

Here is an example, notice how rows 23 and 24 are for the same class period and student, but the only thing different is the teacher names.

pk  id      last    first   period  teacher
14  12345   Smith   John    3       HARRIS
15  12345   Smith   John    8       LEAL
17  12345   Smith   John    1       HOUSTON
23  56789   Doe     Jane    8       MERCER
24  56789   Doe     Jane    8       RUIZ
25  56789   Doe     Jane    3       BECK
26  56789   Doe     Jane    1       STEED

I would like to combine the two rows with the same period number and student name into one row. All the information would remain the same except the two different teacher's names would be combined into something like "Mercer & Ruiz." Ideally the final result would look something like,

24  56789   Doe Jane    8   MERCER & RUIZ

Is this possible using PHP and/or MySQL? I'm not looking for anyone to write the entire code or anything. I just can't seem to think of a way to accomplish it. I'd be happy with any direction/indication of a way to go about this.

As always, thanks for your time and help.

Answer 1

SELECT  MAX(pk), 
        ID,
        `last`, 
        `first`,
        GROUP_CONCAT(teacher SEPARATOR ' & ') teachers
FROM    tableName
// WHERE clause here...
GROUP BY `last`, `first`, `Period`
// ORDER BY clause here....

• SQLFiddle Demo

SOOURCE

• GROUP_CONCAT()

Answer 2

SELECT pk,id,last,first,period GROUP_CONCAT(teacher) 
FROM table 
GROUP BY id, first,last,period

Should do what you need.