postgres學習筆記

字段基本型別

int
char(num)
varchar(num)
serial

更多詳情限制

not null primary key

unique

登入

psql -u dbuser 預設登入進入名為dbuser的資料庫中，如果不存在請-d指定相應進入的資料庫

psql -u username -p port -h localhost -d dbname

命令列

建立資料庫使用者具有超級許可權
createuser dbuser -s ;
createdb dbname ;
password dbuser ;

psql 進入postgres

基本命令 \l 顯示當前所有的資料庫 \c dbname 切換進入資料庫 \c 檢視當前的連線資訊 \d 當前庫的所有表資訊 \d tablename 當前表的所有字段資訊

\q 退出登入

建立使用者

create user dbuser ;
password dbuser ;
create user dbuser with password 'pwd' ;
create database dbname owner dbuser ;

授權

grant all privileges on database dbname to dbuser ;

建立資料庫

create database dbname ;
drop database dbname ;

備份資料

pg_dump -h host -u user dbname >  file.sql.bak

還原資料

psql -h host -u user -d dbname < file.sql.bak

建立新錶

//serial 指定自增
create table users(id serial primary key,name varchar(20) not null,info text,lasttime date,age int not null default 23) ;

插入資料

insert into user_tbl(name, signup_date) values(';張三';, ';2013-12-22';);

選擇記錄

select * from tablename limit length offset start ;

更新資料

update user_tbl set name = '李四'  where name = '張三' ;

刪除記錄

delete from user_tbl where name = '李四' ;

清空表資料

truncate table tset1

delete from tset1

新增字段

alter table user_tbl add email varchar(40);

更新結構

alter table user_tbl alter column signup_date set not null;
alter table gdt_accounts alter system_industry_id type varchar(12) ;

更名字段

alter table user_tbl rename column signup_date to signup;

刪除字段

alter table user_tbl drop column email;

**更名

alter table user_tbl rename to backup_tbl;

刪除**

drop table if exists backup_tbl;

sql優化

postgresql獲取資料庫中所有table表名

select tablename from pg_tables where tablename not like 'pg%' and tablename not like 'sql_%'

order by tablename;

postgresql獲取某個表tablename所有欄位名稱，型別，備註,是否為空等

select a.attname as name, pg_type.typname as typename, col_description(a.attrelid,a.attnum) as comment,a.attnotnull as notnull from pg_class as c,pg_attribute as a inner join pg_type on pg_type.oid = a.atttypid

where c.relname = 'tablename' and a.attrelid = c.oid and a.attnum>0

postgresql獲取某個表tablename的主鍵資訊

select pg_attribute.attname as colname,pg_type.typname as typename,pg_constraint.conname as pk_name from pg_constraint inner join pg_class on pg_constraint.conrelid = pg_class.oid inner join pg_attribute on pg_attribute.attrelid = pg_class.oid and pg_attribute.attnum = pg_constraint.conkey[1] inner join pg_type on pg_type.oid = pg_attribute.atttypid where pg_class.relname = 'tablename'

and pg_constraint.contype='p'

postgresql獲取資料庫中所有view名檢視

select viewname from pg_views

where schemaname ='public'

新增注釋

postgresql給列新增注釋資訊 create table user( userid int not null, phonenumber int); comment on column user.userid is 'the user id'; postgresql給表新增注釋資訊 comment on table user is 'our session logs'; postgresql 查詢注釋資訊 select description from pg_descriptionjoin pg_class on pg_description.objoid = pg_class.oidwhere relname = 'user' 查詢指定schema下注釋資訊

select description from pg_description join pg_class on pg_description.objoid = pg_class.oid join pg_namespace on pg_class.relnamespace = pg_namespace.oid where relname = '' and nspname=''

新增索引

建立索引

create index indexname on test1 (column);

分析優化

explain analyze  select 1 from tbl_user where user_spell like '%cyl%';

postgres學習筆記

django框架學習十六 postgreSQL

postgres遞迴查詢

修改postgres編碼

postgres學習筆記

django框架學習十六 postgreSQL

postgres遞迴查詢

修改postgres編碼

相關推薦