alter user wang set default_transaction_read_only=on;
grant all on database test to wang;
grant select on all database test to wang;
grant select on all tables in schema public to wang;   // 起作用的是这句 要进入数据库test 操作,在那个db环境执行就授哪个db的权

ve=# grant all on schema public to foo ;
ve=# grant select,insert,update,delete on test to foo ;
ve=# grant select,insert,update,delete on public.test to foo ;

revoke all on database company from wang;   #撤销用户wang对数据库company 的所有权限
revoke select on all tables in schema public from wang; 

lyy=# revoke all on test1 from public;
REVOKE
lyy=# revoke all on test2 from public;
REVOKE

lyy=# revoke all on pg_class from public;
REVOKE
lyy=# revoke all on pg_class from yy;
REVOKE

lyy=# ALTER TABLE test1 OWNER TO yy; 
lyy=# \q

/* 赋给用户表的所有权限 */
GRANT ALL ON tablename TO user; 
/* 赋给用户数据库的所有权限 */
GRANT ALL PRIVILEGES ON DATABASE dbname TO dbuser;

/* 撤销用户权限 */
REVOKE privileges ON tablename FROM user;

/* 创建数据库 */
create database dbname; 

/* 删除数据库 */
drop database dbname; 

/* 增加让主键自增的权限 */
grant all on sequence tablename_keyname_seq to webuser;

 /* 重命名一个表 */
alter table [表名A] rename to [表名B]; 

/* 删除一个表 */
drop table [表名]; 

/* 在已有的表里添加字段 */
alter table [表名] add column [字段名] [类型]; 

/* 删除表中的字段 */
alter table [表名] drop column [字段名]; 

/* 重命名一个字段 */
alter table [表名] rename column [字段名A] to [字段名B]; 

/* 给一个字段设置缺省值 */
alter table [表名] alter column [字段名] set default [新的默认值];

/* 去除缺省值 */
alter table [表名] alter column [字段名] drop default; 

/* 插入数据 */
insert into 表名 ([字段名m],[字段名n],......) values ([列m的值],[列n的值],......); 

/* 修改数据 */
update [表名] set [目标字段名]=[目标值] where ...; 

/* 删除数据 */
delete from [表名] where ...; 

/* 删除表 */
delete from [表名];

/* 查询 */
SELECT * FROM dbname WHERE ...;

/* 创建表 */
create table (
  [字段名1] [类型1] primary key,

postgres=# create user username with password '****';

postgres=# create database dbtest owner username; -- 创建数据库指定所属者

postgres=# grant all on database dbtest to username; -- 将dbtest所有权限赋值给username

psql -U username databasename < /data/dum.sql -- 用户名和数据库名

lyy=# \c - yy
FATAL: Peer authentication failed for user "yy"
Previous connection kept

psql -E -U yy -d lyy
Password for user yy:
psql: FATAL: permission denied for database "lyy"
DETAIL: User does not have CONNECT privilege.

#grant connect on database lyy to yy;