1.创建用户user1，分别在数据库musicdb1、数据库musicdb2创建表t11,t21并分别插入数据
su - omm
gsql -r
CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE DATABASE musicdb WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb1 WITH TABLESPACE = music_tbs;
CREATE DATABASE musicdb2 WITH TABLESPACE = music_tbs;
CREATE USER user1 IDENTIFIED BY 'kunpeng@1234';
ALTER USER user1 SYSADMIN;
--用户user1登录到数据库musicdb1，创建表t11，并插入、查看数据
\c musicdb1 user1
create table t11(col1 char(20));
insert into t11 values('Hello openGauss! 11');
select * from t11;
--用户user1登录到数据库musicdb2，创建表t21，并插入、查看数据
\c musicdb2 user1
create table t21(col1 char(20));
insert into t21 values('Hello openGauss! 22');
select * from t21;
root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type “help” for help. omm=# CREATE TABLESPACE music_tbs RELATIVE LOCATION ‘tablespace/test_ts1’;
CREATE TABLESPACE
omm=# CREATE DATABASE musicdb WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE DATABASE musicdb1 WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE DATABASE musicdb2 WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE USER user1 IDENTIFIED BY ‘kunpeng@1234’;
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=#
omm=# ALTER USER user1 SYSADMIN;
ALTER ROLE
omm=# \c musicdb1 user1
Password for user user1:
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database “musicdb1” as user “user1”.
musicdb1=> create table t11(col1 char(20));
CREATE TABLE
musicdb1=> insert into t11 values(‘Hello openGauss! 11’);
INSERT 0 1
musicdb1=> select * from t11;
col1
-.---------------------
Hello openGauss! 11
(1 row) musicdb1=> \c musicdb2 user1
Password for user user1:
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database “musicdb2” as user “user1”.
musicdb2=> create table t21(col1 char(20));
CREATE TABLE
musicdb2=> insert into t21 values(‘Hello openGauss! 22’);
INSERT 0 1
musicdb2=> select * from t21;
col1
–.--------------------
Hello openGauss! 22
(1 row) musicdb2=> |
2.user1用户连接到数据库musicdb1，并访问数据库musicdb1下的表t11：
可以使用DatabaseName.SchemaName.TableName来标识openGauss中的一个表。
–使用user1用户连接到数据库musicdb1，访问数据库musicdb1下的表t11
\c musicdb1 user1
select * from musicdb1.public.t11;
musicdb2=> \c musicdb1 user1
Password for user user1:
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database “musicdb1” as user “user1”.
musicdb1=> select * from musicdb1.public.t11;
col1
-.---------------------
Hello openGauss! 11
(1 row) musicdb1=> |
3.在这个连接中（使用数据库用户user1连接到数据库musicdb1）访问数据库musicdb2下的t21表(会报错)：
select * from musicdb2.public.t21;
ERROR: cross-database references are not implemented: "musicdb2.public.t21"
LINE 1: select * from musicdb2.public.t21;
musicdb1=> select * from musicdb2.public.t21;
ERROR: cross-database references are not implemented: “musicdb2.public.t21”
LINE 1: select * from musicdb2.public.t21;
^
musicdb1=> |
4.使用数据库用户user1连接到数据库musicdb2，访问数据库musicdb2下的t21表：
–可以正常访问，数据库中的表是存在的。但不能跨库访问。
\c musicdb2 user1
select * from musicdb2.public.t21;
musicdb1=> \c musicdb2 user1
Password for user user1:
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database “musicdb2” as user “user1”.
musicdb2=> select * from musicdb2.public.t21;
col1
-.---------------------
Hello openGauss! 22
(1 row) musicdb2=> |
