pgsql，即PostgreSQL安装后默认的pg_hba.conf内容如下，小白可能看不懂意思，这里简单讲解下
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domain socket connections only
local all all trust
# IPv4 local connections:
host all all 127.0.0.1/32 trust
# IPv6 local connections:
host all all ::1/128 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
local replication all trust
host replication all 127.0.0.1/32 trust
host replication all ::1/128 trust
host jww root 127.0.0.1/32 md5
host all name1 0.0.0.0/0 md5
将上述的配置文件整理成如下表格，会比较清晰！
| TYPE | DATABASE | USER | ADDRESS | METHOD |
|---|---|---|---|---|
| 类型，一般就host或local local是仅对于本地socket连接 |
数据库名称，all就是全部，不限定 replication是从数据库 |
数据库用户名，all就是全部，不限定 | 指定地址，0.0.0.0/0就是任意地址，127.0.0.1/32，::1/128都是本地 | trust或md5,trust就是信任，连接时无需密码；md5就是需要密码 |
| local | all | all | trust | |
| host | all | all | 127.0.0.1/32 | trust |
| host | all | all | ::1/128 | trust |
| local | replication | all | trust | |
| host | replication | all | 127.0.0.1/32 | trust |
| host | replication | all | ::1/128 | trust |
| host | test_db | root | 127.0.0.1/32 | md5 |
| host | product_db | name1 | 0.0.0.0/0 | md5 |
因此，安装好pgsql后，默认的配置，本地无需密码就可访问了，而不必担心外网无密码连接
而当需要外网连接时，仅需添加一行配置即可，建议是指定的ip地址，需要密码（METHOD填md5，千万不要填trust了）