PHP MySQL将多列转换为多行

Question

So I have a database table that is structured something like this...

NAME | PHONE | EMAIL1 | EMAIL2 | EMAIL3

Those would be my columns, imagine this is a row in that database..

John | 555-555-5555 | email1@website.com | email2@website.com | email3@website.com

I need to be able to dump these entries to a CSV which I have the code for working already BUT the format is the issue.

I need each email to be displayed on a single row with the corresponding name and number, in the following format...

John | 555-555-5555 | email1@website.com
John | 555-555-5555 | email2@website.com
John | 555-555-5555 | email3@website.com

I need to retrieve thousands of rows and display them this way, is there some way using a PHP while loop I can display the rows from my database table in this format? Any help is greatly appreciated.

Answer 1

This process is called unpivoting.
And is most commonly done with UNION ALL within MySQL.

SELECT 
   NAME
 , PHONE
 , EMAIL1 
FROM 
 table

UNION ALL 

SELECT 
   NAME
 , PHONE
 , EMAIL2 
FROM 
 table

UNION ALL 

SELECT 
   NAME
 , PHONE
 , EMAIL3 
FROM 
 table