批量修改数据库中数据（对数据库中某字段的值增加一个逗号，如果改值不存在逗号时）
update net_shop n
set n.payment_id = (select (case
when substr(n1.payment_id,
length(n1.payment_id),
1) = ',' then
n1.payment_id
else
n1.payment_id || ','
end) payment_id
from net_shop n1
where n1.payment_id is not null
and n1.id = n.id
),
n.carriage_id = (select (case
when substr(n1.carriage_id,
length(n1.carriage_id),
1) = ',' then
n1.carriage_id
else
n1.carriage_id || ','
end) payment_id
from net_shop n1
where n1.carriage_id is not null
and n1.id = n.id
);