psycopg2

簡介

Psycopg 是Python語言的PostgreSQL數據庫接口。 它的主要優勢在於完全支持Python DB API 2.0，以及安全的多線程支持。它適用於隨時創建、銷毀大量游標的、和產生大量並發INSERT、UPDATE操作的多線程數據庫應用。Psycopg包內含 ZPsycopgDA，一個Zope數據庫接口。

示例1：新建表、插入、修改

#-*- coding: utf-8 -*-
import psycopg2

def main(user,pwd,ip,port,dbname):
    connection = "dbname=%s user=%s password=%s host=%s port=%s" % (dbname, user,pwd, ip, port)

    db = psycopg2.connect(connection)
    cur = db.cursor()
    #創建表
    sql_stat = "CREATE TABLE test_class_id(id INT PRIMARY kEY NOT NULL, test_class TEXT, test_id CHAR(10))";
    cur.execute(sql_stat)
    #插入表
    sql_stat = "insert into test_class_id(id, test_class, test_id) values (1, 'a', '3')"
    cur.execute(sql_stat)

    sql_stat = "insert into test_class_id(id, test_class, test_id) values (2, 'a', '3')"
    cur.execute(sql_stat)
    #更改字段值
    sql_stat = "update test_class_id set test_class='b' where id=1"
    cur.execute(sql_stat)

    db.commit()

if __name__ == "__main__":
    user = '****'
    pwd = '****'
    ip = '***'
    port = '5432'
    dbname = '****'
    main(user, pwd, ip, port, dbname)
    print "Done~~"

結果

注：這里有多次提交execute  最后一次提交commit，如果沒有最后的一次commit，你們前面的提交也是不執行的。

示例2：批量表操作

 -*- coding: utf-8 -*-
import psycopg2

class_ids = []
class_ids.append({"test_id": 1, "test_class":"A", "test_id":"1"})
class_ids.append({"test_id": 2, "test_class":"A", "test_id":"2"})
class_ids.append({"test_id": 3, "test_class":"B", "test_id":"3"})

def main(user,pwd,ip,port,dbname):
    connection = "dbname=%s user=%s password=%s host=%s port=%s" % (dbname, user,pwd, ip, port)
    db = psycopg2.connect(connection)
    cur = db.cursor()

    #sql_del = "delete from cdb_chk_group"
    #cur.execute(sql_del)
 #批量操作
    sql_stat = 'insert into test_class_id(id, test_class, test_id) values (%(test_id)s, %(test_class)s,%(test_id)s)'
    cur.executemany(sql_stat, class_ids)

    db.commit()

if __name__ == "__main__":
    user = '****'
    pwd = '****'
    ip = '****'
    port = '5432'
    dbname = '****'
    main(user, pwd, ip, port, dbname)
    print "Done~~"

驗證

用法補充

1. 查詢數據，並輸出結果

查詢一條

>>> cur.execute("select * from test;")
>>> cur.fetchone()
(1, 100, "abc'def")

查詢所有條

>>> cur.execute("select * from test;")
>>> cur.fetchall()
[(1, 100, "abc'def"),(2, 100, "abc'def")]