github.com/matrixorigin/matrixone@v0.7.0/test/distributed/cases/function/func_aggr_group_concat.test (about)

     1  drop table if exists t1;
     2  create table t1(a int,b text,c text);
     3  insert into t1 values(1,"a","bc"),(2,"ab","c"),(3,"aa","bb"),(3,"aa","bb");
     4  select group_concat(distinct a,b,c separator '|') from t1;
     5  select group_concat(distinct b,c separator '|') from t1 group by a;
     6  select group_concat(distinct b,c separator '|') from t1;