rewrite

sqlite3/main.py

@@ -1,57 +1,151 @@
-import sqlite3
+import os
 from flask import Flask, request, jsonify, g
+from sqlalchemy import (
+    create_engine, MetaData, Table, select, insert, update, delete, text
+)
+from sqlalchemy.exc import SQLAlchemyError
 from waitress import serve
 
 app = Flask(__name__)
-app.config['DATABASE'] = 'database.db'
 
-def get_db():
-    if 'db' not in g:
-        conn = sqlite3.connect(app.config['DATABASE'])
-        conn.row_factory = sqlite3.Row
-        g.db = conn
-    return g.db
+# 数据库配置
+DATABASE_URL = os.environ.get('DATABASE_URL', 'sqlite:///database.db')
+engine = create_engine(DATABASE_URL)
 
-@app.teardown_appcontext
-def close_db(exception):
-    db = g.pop('db', None)
-    if db is not None:
-        db.close()
+# 缓存反射的元数据（避免每次请求都反射）
+metadata = MetaData()
+
+def get_table(table_name):
+    """反射表对象（若已缓存则直接返回）"""
+    if table_name not in metadata.tables:
+        Table(table_name, metadata, autoload_with=engine)
+    return metadata.tables[table_name]
+
+def build_where(table, conditions):
+    """将条件字典转换为 SQLAlchemy 条件表达式"""
+    if not conditions:
+        return None
+    clauses = []
+    for col, val in conditions.items():
+        column = table.columns[col]
+        if isinstance(val, dict):
+            # 支持多种比较操作
+            if 'eq' in val:
+                clauses.append(column == val['eq'])
+            if 'ne' in val:
+                clauses.append(column != val['ne'])
+            if 'gt' in val:
+                clauses.append(column > val['gt'])
+            if 'lt' in val:
+                clauses.append(column < val['lt'])
+            if 'ge' in val:
+                clauses.append(column >= val['ge'])
+            if 'le' in val:
+                clauses.append(column <= val['le'])
+            if 'like' in val:
+                clauses.append(column.like(val['like']))
+            if 'in' in val:
+                clauses.append(column.in_(val['in']))
+        else:
+            # 直接等值比较
+            clauses.append(column == val)
+    from sqlalchemy import and_
+    return and_(*clauses)
 
 @app.route('/execute', methods=['POST'])
-def execute_sql():
+def execute_structured():
     data = request.get_json()
-    if not data or 'sql' not in data:
-        return jsonify({'success': False, 'error': '缺少 sql 字段'}), 400
+    if not data:
+        return jsonify({'success': False, 'error': '请求体不能为空'}), 400
 
-    sql = data['sql'].strip()
-    params = data.get('params', [])
-
-    # 参数必须是列表、元组或字典
-    if not isinstance(params, (list, tuple, dict)):
-        params = []
+    action = data.get('action', 'select')
+    table_name = data.get('table')
+    if not table_name:
+        return jsonify({'success': False, 'error': '缺少 table 字段'}), 400
 
     try:
-        db = get_db()
-        cur = db.execute(sql, params)
-        db.commit()
-
-        try:
-            rows = cur.fetchall()
-            result = [dict(row) for row in rows]
-        except Exception:
-            result = []
-
-        return jsonify({
-            'success': True,
-            'data': result
-        })
+        table = get_table(table_name)
     except Exception as e:
-        db = g.get('db')
-        if db:
-            db.rollback()
+        return jsonify({'success': False, 'error': f'表加载失败: {str(e)}'}), 400
+
+    conn = None
+    try:
+        conn = engine.connect()
+        result = []
+        if action == 'select':
+            columns = data.get('columns', None)
+            if columns:
+                cols = [table.columns[c] for c in columns]
+            else:
+                cols = [table]   # select *
+
+            stmt = select(*cols)
+            where_cond = build_where(table, data.get('where'))
+            if where_cond is not None:
+                stmt = stmt.where(where_cond)
+
+            # 排序
+            order_by = data.get('order_by')
+            if order_by:
+                for item in order_by:
+                    col = table.columns[item['column']]
+                    stmt = stmt.order_by(col.desc() if item.get('desc') else col.asc())
+
+            # 分页
+            limit = data.get('limit')
+            if limit is not None:
+                stmt = stmt.limit(limit)
+            offset = data.get('offset')
+            if offset is not None:
+                stmt = stmt.offset(offset)
+
+            res = conn.execute(stmt)
+            rows = res.fetchall()
+            result = [dict(row._mapping) for row in rows]
+
+        elif action == 'insert':
+            values = data.get('values', {})
+            stmt = insert(table).values(**values)
+            res = conn.execute(stmt)
+            conn.commit()
+            result = [{'lastrowid': res.lastrowid}] if hasattr(res, 'lastrowid') else []
+
+        elif action == 'update':
+            values = data.get('values', {})
+            where_cond = build_where(table, data.get('where'))
+            stmt = update(table).values(**values)
+            if where_cond is not None:
+                stmt = stmt.where(where_cond)
+            res = conn.execute(stmt)
+            conn.commit()
+            result = [{'rowcount': res.rowcount}]
+
+        elif action == 'delete':
+            where_cond = build_where(table, data.get('where'))
+            stmt = delete(table)
+            if where_cond is not None:
+                stmt = stmt.where(where_cond)
+            res = conn.execute(stmt)
+            conn.commit()
+            result = [{'rowcount': res.rowcount}]
+
+        else:
+            return jsonify({'success': False, 'error': f'不支持的操作: {action}'}), 400
+
+        return jsonify({'success': True, 'data': result})
+
+    except SQLAlchemyError as e:
+        if conn:
+            conn.rollback()
         return jsonify({'success': False, 'error': str(e)}), 400
+    except Exception as e:
+        if conn:
+            conn.rollback()
+        return jsonify({'success': False, 'error': str(e)}), 400
+    finally:
+        if conn:
+            conn.close()
 
 if __name__ == '__main__':
-    # 单线程单进程，绑定 127.0.0.1:8005
-    serve(app, host='127.0.0.1', port=8005, threads=1)
+    # 单线程单进程，绑定 127.0.0.1
+    serve(app, host='127.0.0.1', port=8005, threads=1)