How to transpose a table in SQLite?

Question

Hello so I have a table as such in SQlite:

   User    |  Group  |   Role    
John Smith |   A     |   admin
John Smith |   B     |   user
Jane Doe   |   A            


        

Answer 1

The excellent solution offered by @CPerkins has the potential drawback of losing information. For example, consider what would happen if the data for "Jack Brown" was presented in two rows:

Jack Brown |   A     |   admin
Jack Brown |   A     |   user

To ensure no information is lost, one could use GROUP_CONCAT instead of MAX:

SELECT User, 
       GROUP_CONCAT(CASE WHEN "group" == 'A' THEN role END) as A,
       GROUP_CONCAT(CASE WHEN "group" == 'B' THEN role END) as B,
       GROUP_CONCAT(CASE WHEN "group" == 'C' THEN role END) as C
FROM SO52961250 t
GROUP BY User;