在Linux环境使用psycopg2第三方库连接集群

1. 以root用户登录Linux环境。
2. 执行以下命令创建python_dws.py文件。

   vi python_dws.py

   请复制粘贴以下内容放入python_dws.py文件中：

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   #!/usr/bin/python# -*- coding: UTF-8 -*- from __future__ import print_function import psycopg2 def create_table(connection): print("Begin to create table") try: cursor = connection.cursor() cursor.execute("drop table if exists test;" "create table test(id int, name text);") connection.commit() except psycopg2.ProgrammingError as e: print(e) else: print("Table created successfully") cursor.close() def insert_data(connection): print("Begin to insert data") try: cursor = connection.cursor() cursor.execute("insert into test values(1,'number1');") cursor.execute("insert into test values(2,'number2');") cursor.execute("insert into test values(3,'number3');") connection.commit() except psycopg2.ProgrammingError as e: print(e) else: print("Insert data successfully") cursor.close() def update_data(connection): print("Begin to update data") try: cursor = connection.cursor() cursor.execute("update test set name = 'numberupdated' where id=1;") connection.commit() print("Total number of rows updated :", cursor.rowcount) cursor.execute("select * from test order by 1;") rows = cursor.fetchall() for row in rows: print("id = ", row[0]) print("name = ", row[1], "\n") except psycopg2.ProgrammingError as e: print(e) else: print("After Update, Operation done successfully") def delete_data(connection): print("Begin to delete data") try: cursor = connection.cursor() cursor.execute("delete from test where id=3;") connection.commit() print("Total number of rows deleted :", cursor.rowcount) cursor.execute("select * from test order by 1;") rows = cursor.fetchall() for row in rows: print("id = ", row[0]) print("name = ", row[1], "\n") except psycopg2.ProgrammingError as e: print(e) else: print("After Delete,Operation done successfully") def select_data(connection): print("Begin to select data") try: cursor = connection.cursor() cursor.execute("select * from test order by 1;") rows = cursor.fetchall() for row in rows: print("id = ", row[0]) print("name = ", row[1], "\n") except psycopg2.ProgrammingError as e: print(e) print("select failed") else: print("Operation done successfully") cursor.close() if __name__ == '__main__': try: conn = psycopg2.connect(host='10.154.70.231', port='8000', database='gaussdb', # 需要连接的database user='dbadmin', password='password') # 数据库用户密码 except psycopg2.DatabaseError as ex: print(ex) print("Connect database failed") else: print("Opened database successfully") create_table(conn) insert_data(conn) select_data(conn) update_data(conn) delete_data(conn) conn.close()

3. 按照实际集群信息，修改python_dws.py文件中的集群公网访问地址、集群端口号、数据库名称、数据库用户名、数据库密码。

   psycopg2接口不提供重试连接的能力，您需要在业务代码中实现重试处理。

   12345

   conn = psycopg2.connect(host='10.154.70.231', port='8000', database='gaussdb', # 需要连接的database user='dbadmin', password='password') # 数据库用户密码

4. 执行以下命令，使用psycopg第三方库连接集群。

   python python_dws.py