sqlite3 concatenate a column by group

there is function:

group_concat(X) group_concat(X,Y) So we can easily from

The group_concat() function returns a string which is the concatenation of all non-NULL values of X. If parameter Y is present then it is used as the separator between instances of X. A comma (",") is used as the separator if Y is omitted. The order of the concatenated elements is arbitrary.

So we can easily from say, we have table tname as 

id|attr

1|black

1|female

2|male

2|white

3|other

to by ``select id, group_concat(attr) from tname group by id'':

1|black,female

2|white,male

3|other