MySQL: variable = variable + select statement

Question

I've got several records in a temp table, and I'd like to take a value from each record and add it to a variable, eg

color          | caption
--------------------------------
red              stop
blue             state line
yellow           yield
orange           construction

var1 = 'red;blue;yellow;orange'

In MSSQL, I could do that this way:

-- MSSQL
select var1 = var1 + color
from signShapes

In MySQL, that doesn't work. I'd just get "orange."

-- mySQL
select var1 = concat(var1, color)
from signShapes

No, I know I could accomplish this with a cursor or a loop. I'm curious if I could do this without either, similarly to the MSSQL method.

Answer 1

 SELECT var1 = GROUP_CONCAT(color SEPARATOR ';')
 FROM signShapes
 GROUP BY color;

Answer 2

Why not just do this?

select var1 = group_concat(color separator ';')
from signShapes;