chore: initialize lawyers crawler project

Db.py

@@ -0,0 +1,58 @@
+import pymysql
+from config import DB_CONFIG
+
+class Db:
+    def __enter__(self):
+        # 使用配置文件中的信息
+        self.db = pymysql.connect(**DB_CONFIG)
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        # 关闭数据库连接
+        self.db.close()
+
+    # 插入数据
+    def insert_data(self, table_name, data):
+        cursor = self.db.cursor()
+        sql = f"INSERT INTO {table_name} ({', '.join(data.keys())}) VALUES ({', '.join(['%s'] * len(data))})"
+        cursor.execute(sql, list(data.values()))
+        self.db.commit()
+        inserted_id = cursor.lastrowid  # 获取插入行的 ID
+        cursor.close()
+        return inserted_id
+
+    # 查询数据
+    def select_data(self, table_name, columns="*", condition=None):
+        cursor = self.db.cursor(pymysql.cursors.DictCursor)
+        sql = f"SELECT {columns} FROM {table_name}"
+        if condition:
+            sql += f" WHERE {condition}"
+        cursor.execute(sql)
+        result = cursor.fetchall()
+        cursor.close()
+        return result
+
+    # 删除数据
+    def delete_data(self, table_name, condition):
+        cursor = self.db.cursor()
+        sql = f"DELETE FROM {table_name} WHERE {condition}"
+        cursor.execute(sql)
+        self.db.commit()
+        cursor.close()
+
+    # 更新数据
+    def update_data(self, table_name, data, condition):
+        cursor = self.db.cursor()
+        set_clause = ", ".join([f"{key} = %s" for key in data.keys()])
+        sql = f"UPDATE {table_name} SET {set_clause} WHERE {condition}"
+        cursor.execute(sql, list(data.values()))
+        self.db.commit()
+        cursor.close()
+    # 判断数据是否存在
+    def is_data_exist(self, table_name, condition):
+        cursor = self.db.cursor()
+        sql = f"SELECT COUNT(*) FROM {table_name} WHERE {condition}"
+        cursor.execute(sql)
+        result = cursor.fetchone()
+        cursor.close()
+        return result[0] > 0