将多行记录转化为一个字符串，用array_to_string内置函数即可！
select array_to_string(array(
select distinct name from tab where 1=1
),'-->') as strs;
将一个字符串转化为多行记录，用regexp_splite_to_table即可！
select regexp_splite_to_table('asd,qwe,qeq,ere,fds,ert',',') as id;
分割之后再转化为整数
select cast( regexp_splite_to_table('1,2,3,4,5,6',',') as integer) as id;