数据库编程

postgresql指令

To migrate existing data from a previous major version of PostgreSQL run:

brew postgresql-upgrade-database

To have launchd start postgresql now and restart at login:

brew services start postgresql

Or, if you don't want/need a background service you can just run:

pg_ctl -D /usr/local/var/postgres start

psycopg2使用

我是用的是Pyhton3自带的IDEL：

>>> import psycopg2
>>> cxn = psycopg2.connect(user='postgres')
>>> cur = cxn.cursor()
>>> cur.fetchall()
>>> cur.execute('SELECT * FROM pg_database')
>>> rows = cur.fetchall()
>>> for i in rows:
    print(i)

('noduez', 10, 6, 'C', 'C', False, True, -1, 13381, '561', '1', 1663, None)
('template1', 10, 6, 'C', 'C', True, True, -1, 13381, '561', '1', 1663, '{=c/noduez,noduez=CTc/noduez}')
('template0', 10, 6, 'C', 'C', True, False, -1, 13381, '561', '1', 1663, '{=c/noduez,noduez=CTc/noduez}')
('postgres', 16385, 6, 'C', 'C', False, True, -1, 13381, '561', '1', 1663, '{=Tc/postgres,postgres=CTc/postgres}')
>>> 

sqlite使用

>>> import sqlite3
>>> cxn = sqlite3.connect('/Users/mac/sqlite_test/test.sqlite3')
>>> cur = cxn.cursor()
>>> cur.execute('create tables users(login varchar(8), userid integer)')
>>> cur.execute('insert into users values("jhon", 100)')
<sqlite3.Cursor object at 0x1148fe0a0>
>>> cur.execute('insert into users values("jane", 110)')
<sqlite3.Cursor object at 0x1148fe0a0>
>>> cur.execute('select * from users')
 <sqlite3.Cursor object at 0x1148fe0a0>
>>> for eachUser in cur.fetchall():
    print(eachUser)

('jhon', 100)
('jane', 110)
>>>