PostgreSQL 常用语句

╰+攻爆jí腚メ 2021-11-22 05:12 303阅读 0赞

postgres=# create database mydb;
    CREATE DATABASE
    
    
    postgres=# alter database mydb;
    ALTER DATABASE
    
    
    postgres=# create table mydbtable(name varchar(80),year int);
    CREATE TABLE
    
    
    postgres=# create table mydbtable(name varchar(80),year int);
    ERROR:  relation "mydbtable" already exists
    
    
    postgres=# insert into mydbtable (name,year) values ('xiaoming',23);
    INSERT 0 1
    
    
    postgres=# table mydbtable;
       name   | year 
    ----------+------
     xiaoming |   23
    (1 row)
    
    
    postgres=# select * from mydbtable;
       name   | year 
    ----------+------
     xiaoming |   23
    (1 row)
    
    
    
    postgres=# select name from mydbtable;
       name   
    ----------
     xiaoming
    (1 row)
    
    
    
    postgres=# insert into mydbtable (name,year) values ('xiaohong',23);
    INSERT 0 1
    postgres=# select name from mydbtable;
       name   
    ----------
     xiaoming
     xiaohong
    (2 rows)
    
    
    
    postgres=# update mydbtable set name = 'xiaohei' where name='xiaohong';
    UPDATE 1
    postgres=# select name from mydbtable;
       name   
    ----------
     xiaoming
     xiaohei
    (2 rows)
    postgres=# 
    
    
    postgres=# delete from mydbtable where name='xiaohei';
    DELETE 1
    postgres=# select name from mydbtable;
       name   
    ----------
     xiaoming
    (1 row)
    
    
    postgres=# delete from mydbtable;
    DELETE 1
    postgres=# select * from mydbtable;
     name | year 
    ------+------
    (0 rows)
    postgres=# 
    
    
    postgres=# create database testdb;
    CREATE DATABASE
    
    
    postgres=# alter database testdb;
    ALTER DATABASE

转载于:https://www.cnblogs.com/sea-stream/p/11197772.html