Python 鏈接 PostgreSQL 數據庫

本文測試環境爲Windows 7和PostgreSQL 10.3。

首先檢查安裝psycopg2。

pip install psycopg2

建立數據庫鏈接，執行數據庫語句。

import psycopg2
#建立數據庫鏈接，數據庫配置信息根據實際狀況填寫
LocalPostgreSQLConnection = psycopg2.connect( host="127.0.0.1", port="5432",database="test", user="root", password="root")
cur = LocalPostgreSQLConnection.cursor()
cur.execute('''create table company
 (id int primary key not null,
 name text not null,
 age int not null,
 address char(50),
 salary real);''')
#提交事務，未提交數據庫沒法查詢結果
LocalPostgreSQLConnection.commit()
#關閉數據庫鏈接
LocalPostgreSQLConnection.close()

數據插入實例。

import psycopg2
LocalPostgreSQLConnection=psycopg2.connect(host="127.0.0.1",port="5432",database="test",user="root",password="root")
cur=LocalPostgreSQLConnection.cursor()
cur.execute('''
insert into company values(1,'Bill',22,'New York',22.50);
''')

LocalPostgreSQLConnection.commit()
LocalPostgreSQLConnection.close()

簡單查詢。

import psycopg2
LocalPostgreSQLConnection=psycopg2.connect(host="127.0.0.1",port="5432",database="test",user="root",password="root")
cur=LocalPostgreSQLConnection.cursor()
cur.execute("select id, name, address, salary from company")
rows = cur.fetchall()
#cursor.fetchall() 這個例程獲取全部查詢結果（剩餘）行，返回一個列表。空行時則返回空列表。
for row in rows:
 print("ID = ", row[0])
 print("NAME = ", row[1])
 print("ADDRESS = ", row[2])
 print("SALARY = ", row[3], "\n")
 print("select database successfully")
LocalPostgreSQLConnection.commit()
LocalPostgreSQLConnection.close()