安装 psycopg2

1、下载并解压包

下载网址

https://opengauss.org/zh/download/

解压包

# tar -zxvf openGauss-5.0.2-CentOS-x86_64-Python.tar.gz 

解压安装包后，会得到两个目录lib和psycopg2。lib是psycopg2依赖的libpq等C动态库文件。

2、将解压后的lib和psycopg2目录拷贝到Python解释器的site-packages 下让python可以索引到

2.1、查找 site-packages 目录所在位置

# python3 -c "from distutils.sysconfig import get_python_lib;print(get_python_lib())"
/usr/lib/python3.6/site-packages

2.2、拷贝

# cp -rp psycopg2 /usr/lib/python3.6/site-packages
# cp -rp lib /usr/lib/python3.6/site-packages
# chmod 755 /usr/lib/python3.6/site-packages/psycopg2

3、切换到运行用户，设置环境变量

$ echo "export LD_LIBRARY_PATH=/usr/lib/python3.6/site-packages/lib:$LD_LIBRARY_PATH" >> ~/.bashrc
$ source ~/.bashrc

使用固定ip访问数据库

$ python3
Python 3.6.8 (default, Nov 16 2020, 16:55:22)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux
Type "help", "copyright", "credits" or "license" for more information.
import psycopg2
conn = psycopg2.connect(database="testdb", user="testuser", password="testuser", host="192.168.100.10", port="1921")
cur = conn.cursor()
cur.execute("select * from test")
rows = cur.fetchall()
for row in rows:
    print("ID = ",row[0],"NAME = ",row[1])

输出如下：

访问数据库primary节点

conn = psycopg2.connect(host="ip1[,ip2,ip3]",port=port1,database=db,user=user, password=password,target_session_attrs="read-write")

参考

https://gitee.com/opengauss/openGauss-connector-python-psycopg2/#%E5%AE%89%E8%A3%85-psycopg2