<think>我们遇到了连接openGauss时SASL认证机制不支持的问题,并且尝试了多种方法仍然报错。现在考虑使用opengauss-python-driver扩展(即openGauss官方提供的Python驱动)来连接数据库。这个驱动可能对openGauss有更好的兼容性。
### 解决方案:使用opengauss-python-driver连接openGauss
#### 步骤1:安装opengauss-python-driver
首先,我们需要安装这个驱动。可以通过pip安装:
```bash
pip install opengauss-python-driver
```
#### 步骤2:编写连接代码
使用opengauss-python-driver连接数据库的代码与使用psycopg2类似,但有一些特定的参数和注意事项。
以下是一个完整的连接示例类:
```python
from opengauss_python import openGauss
from opengauss_python.errors import OperationalError
import logging
class OpenGaussDriverConnector:
def __init__(self, dbname, user, password, host, port=5432):
self.dbname = dbname
self.user = user
self.password = password
self.host = host
self.port = port
self.logger = logging.getLogger("OpenGaussDriverConnector")
logging.basicConfig(level=logging.INFO)
def connect(self):
"""使用opengauss-python-driver建立连接"""
try:
# 使用openGauss.connect创建连接
conn = openGauss.connect(
dbname=self.dbname,
user=self.user,
password=self.password,
host=self.host,
port=self.port
)
self.logger.info("成功使用opengauss-python-driver连接到数据库")
return conn
except OperationalError as e:
self.logger.error(f"连接失败: {e}")
raise
# 使用示例
if __name__ == "__main__":
# 创建连接器实例
connector = OpenGaussDriverConnector(
dbname="mydb",
user="myuser",
password="mypassword",
host="127.0.0.1",
port=5432
)
try:
conn = connector.connect()
# 创建游标
cursor = conn.cursor()
cursor.execute("SELECT version();")
version = cursor.fetchone()
print("数据库版本:", version[0])
cursor.close()
conn.close()
except OperationalError as e:
print(f"连接过程中发生错误: {e}")
```
#### 代码解释
1. **导入模块**:我们导入了`openGauss`和`OperationalError`。`openGauss`是主要的连接类,`OperationalError`用于捕获操作错误。
2. **连接参数**:在初始化方法中,我们保存了数据库连接所需的参数(数据库名、用户名、密码、主机和端口)。
3. **连接方法**:在`connect`方法中,我们使用`openGauss.connect`方法创建连接。这个方法与psycopg2的`connect`方法类似。
4. **异常处理**:捕获`OperationalError`异常,并记录日志。
#### 注意事项
1. **驱动兼容性**:opengauss-python-driver是openGauss官方维护的驱动,针对openGauss的特性进行了优化,因此兼容性更好。
2. **连接参数**:该驱动支持的参数与psycopg2略有不同,具体可参考官方文档。
3. **SSL连接**:如果需要使用SSL连接,可以传入`sslmode`参数,例如:
```python
conn = openGauss.connect(
...,
sslmode="require"
)
```
#### 备选方案:使用连接字符串
也可以使用连接字符串(DSN)来连接:
```python
dsn = f"host={self.host} port={self.port} dbname={self.dbname} user={self.user} password={self.password}"
conn = openGauss.connect(dsn)
```
#### 错误排查
如果使用opengauss-python-driver仍然遇到问题,可以尝试以下步骤:
1. **检查网络**:确保客户端可以访问数据库服务器的IP和端口。
2. **检查数据库配置**:确认openGauss的`pg_hba.conf`文件中允许客户端的连接。
3. **检查用户权限**:确认连接的用户有权限访问指定的数据库。
### §§相关问题§§:
1. opengauss-python-driver与psycopg2在功能上有哪些主要区别?
2. 如何在openGauss中创建新用户和数据库?
3. 使用opengauss-python-driver如何执行事务操作?
4. 如何配置openGauss以允许远程连接?</think>### 安装与使用 openGauss-Python-Driver 扩展指南
当标准 psycopg2 驱动无法解决 SASL 认证问题时,openGauss 官方提供的 Python 驱动是更可靠的解决方案。以下是完整的安装和使用指南:
#### 安装步骤
```bash
# 1. 安装系统依赖
sudo apt update
sudo apt install -y python3-dev libpq-dev gcc make
# 2. 创建虚拟环境(推荐)
python3 -m venv og_env
source og_env/bin/activate
# 3. 安装 openGauss Python 驱动
pip install opengauss-python-driver cryptography
# 4. 验证安装
python -c "from opengauss_python import openGauss; print(openGauss.__version__)"
```
#### 完整连接类实现
```python
from opengauss_python import openGauss
import logging
import time
from threading import Lock
class OpenGaussDriverConnector:
def __init__(self,
host,
port,
dbname,
user,
password,
max_retries=3,
retry_delay=2,
pool_size=5):
self.conn_params = {
"host": host,
"port": port,
"dbname": dbname,
"user": user,
"password": password,
"sslmode": "prefer"
}
self.max_retries = max_retries
self.retry_delay = retry_delay
self.pool_size = pool_size
self.connection_pool = []
self.lock = Lock()
self.logger = self._setup_logger()
def _setup_logger(self):
logger = logging.getLogger("OpenGaussDriver")
logger.setLevel(logging.DEBUG)
handler = logging.StreamHandler()
formatter = logging.Formatter(
'%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
handler.setFormatter(formatter)
logger.addHandler(handler)
return logger
def _create_connection(self):
"""创建新数据库连接"""
for attempt in range(self.max_retries):
try:
self.logger.info(f"尝试连接数据库 (尝试 {attempt+1}/{self.max_retries})")
conn = openGauss.connect(**self.conn_params)
conn.autocommit = False
return conn
except Exception as e:
self.logger.error(f"连接失败: {str(e)}")
if attempt < self.max_retries - 1:
time.sleep(self.retry_delay)
raise ConnectionError("所有连接尝试均失败")
def initialize_pool(self):
"""初始化连接池"""
with self.lock:
if not self.connection_pool:
self.logger.info(f"初始化连接池 (大小: {self.pool_size})")
self.connection_pool = [
self._create_connection() for _ in range(self.pool_size)
]
def get_connection(self):
"""从池中获取连接"""
self.initialize_pool()
with self.lock:
if not self.connection_pool:
self.logger.warning("连接池为空,创建新连接")
return self._create_connection()
return self.connection_pool.pop()
def release_connection(self, conn):
"""释放连接回池中"""
with self.lock:
if len(self.connection_pool) < self.pool_size:
self.connection_pool.append(conn)
else:
self.logger.debug("连接池已满,关闭额外连接")
conn.close()
def execute_query(self, sql, params=None):
"""执行查询并返回结果"""
conn = self.get_connection()
try:
with conn.cursor() as cursor:
cursor.execute(sql, params)
if cursor.description:
columns = [desc[0] for desc in cursor.description]
results = cursor.fetchall()
return {"columns": columns, "data": results}
else:
return {"affected_rows": cursor.rowcount}
except Exception as e:
conn.rollback()
self.logger.error(f"查询执行失败: {str(e)}")
raise
finally:
self.release_connection(conn)
def close_all(self):
"""关闭所有连接"""
with self.lock:
self.logger.info("关闭所有数据库连接")
for conn in self.connection_pool:
try:
conn.close()
except:
pass
self.connection_pool = []
# 使用示例
if __name__ == "__main__":
# 创建连接器
connector = OpenGaussDriverConnector(
host="127.0.0.1",
port=5432,
dbname="mydb",
user="myuser",
password="mypassword",
pool_size=3
)
try:
# 执行查询
result = connector.execute_query(
"SELECT * FROM pg_catalog.pg_tables WHERE schemaname = %s",
("public",)
)
print("查询结果:")
print("Columns:", result["columns"])
for row in result["data"]:
print(row)
# 执行更新
update_result = connector.execute_query(
"UPDATE my_table SET status = %s WHERE id = %s",
("active", 1001)
)
print(f"更新影响行数: {update_result['affected_rows']}")
finally:
connector.close_all()
```
#### 关键特性说明
1. **连接池管理**
- 初始化时创建固定大小的连接池
- 线程安全的连接获取和释放
- 自动处理连接耗尽情况
2. **健壮的错误处理**
- 自动重试机制
- 详细的日志记录
- 事务回滚保障
3. **高级功能支持**
```python
# 批量插入示例
def bulk_insert(self, table, columns, data):
"""高效批量插入"""
placeholders = ",".join(["%s"] * len(columns))
sql = f"INSERT INTO {table} ({','.join(columns)}) VALUES ({placeholders})"
conn = self.get_connection()
try:
with conn.cursor() as cursor:
cursor.executemany(sql, data)
conn.commit()
return cursor.rowcount
finally:
self.release_connection(conn)
```
#### 性能优化建议
1. **连接参数调优**
```python
# 在连接参数中添加性能优化选项
self.conn_params.update({
"tcp_keepalives_idle": 60, # TCP保活空闲时间
"tcp_keepalives_interval": 10, # 保活探测间隔
"tcp_keepalives_count": 5, # 保活探测次数
"connect_timeout": 10 # 连接超时时间
})
```
2. **SSL/TLS 配置**
```python
# 安全连接配置
self.conn_params.update({
"sslmode": "verify-full",
"sslrootcert": "/path/to/root.crt",
"sslcert": "/path/to/client.crt",
"sslkey": "/path/to/client.key"
})
```
#### 故障排除命令
```bash
# 检查驱动兼容性
python -c "import ssl; print(ssl.OPENSSL_VERSION)"
# 查看驱动支持的协议
python -c "from opengauss_python import openGauss; print(openGauss._ssl.get_supported_protocols())"
# 测试连接性
python -c "from opengauss_python import openGauss; \
conn = openGauss.connect(host='127.0.0.1', port=5432, \
dbname='postgres', user='myuser', password='mypass'); \
print('连接成功!')"
```
#### 替代安装方法(离线环境)
1. 下载预编译包:
```bash
wget https://github.com/opengauss-mirror/openGauss-connector-python/archive/refs/tags/2.0.0.tar.gz
tar -xzf 2.0.0.tar.gz
cd openGauss-connector-python-2.0.0
python setup.py install
```
2. 使用Docker容器:
```Dockerfile
FROM python:3.9-slim
RUN apt update && apt install -y gcc libpq-dev
RUN pip install opengauss-python-driver cryptography
COPY app.py .
CMD ["python", "app.py"]
```
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