add demo DBManage to operate database.

Author: xdai555

demo/mysql_demo.py

@@ -12,3 +12,52 @@
 cur.execute("select * from user")
 print(cur.fetchone())
 
+
+class DBManage:
+    def __init__(self, db_info, db_name) -> None:
+        self.db_name = db_name
+        self.info = db_info
+        self.conn = None
+        self.cursor = None
+        self.connect()
+    
+    def connect(self):
+        try:
+            db_user = self.info['db_user']
+            db_host = self.info['db_host']
+            db_port = int(self.info['db_port'])
+            db_name = self.info['db_name']
+            db_pwd = self.info['db_password']
+
+            self.conn = pymysql.connect(
+                host=db_host,
+                user=db_user,
+                passwd=db_pwd,
+                database=db_name,
+                port=db_port)
+            self.cursor = self.conn.cursor(pymysql.cursors.DictCursor)
+        except Exception as e:
+            raise e
+        
+    def close(self):
+        self.cursor.close()
+        self.conn.close()
+    
+    def __enter__(self):
+        return self
+    
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+    
+    def exec_sql(self, sql):
+        """执行 SQL，以字典的方式获取执行结果
+
+        Args:
+            sql (str): 原生 SQL 语句
+
+        Returns:
+            list: 字典组成的执行结果列表，其中字典的 Key 为数据库表头，Value 为数据。
+        """
+        self.cursor.execute(sql)
+        return self.cursor.fetchall()
+