还好，网上弄到的，，没有dual的数据库，可以试图用select函数不带from数据表的方式来实现返回值。

一段测试代码：

 

try:        conn = psycopg2.connect(database=db.service_name, user=db.username, password=password, host=db.ip, port=db.port)        cursor = conn.cursor()    except Exception, e:        context_dict = {
   'msg': e, 'address': db.ip, 'port': db.port}        return render(request, 'sar/release_info.html', context_dict)    sql = "SELECT 'OK' AS txt"    try:        cursor.execute(sql)        x = cursor.fetchone()[0]    except Exception,e:        context_dict = {
   'msg': "密码认证通过，但SELECT功能出错", 'address': db.ip, 'port': db.port}        return render(request, 'sar/release_info.html', context_dict)    finally:        cursor.close()        conn.close()    if x == 'OK':        context_dict = {
   'msg': "数据库连接正常", 'sql': sql, 'address': db.ip, 'port': db.port }        return render(request, 'sar/release_info.html', context_dict)