Update app.py

app.py

@@ -3,37 +3,37 @@ import sqlite3
 import datetime
 import os
 
-# Create or connect to the database
+DB_PATH = "attendance.db"
+
+# Create database if not exists
 def init_db():
-    conn = sqlite3.connect("attendance.db")
-    c = conn.cursor()
-
-    # Create tables if they don't exist
-    c.execute('''CREATE TABLE IF NOT EXISTS users (
-                    id INTEGER PRIMARY KEY AUTOINCREMENT,
-                    username TEXT UNIQUE,
-                    password TEXT,
-                    role TEXT,
-                    device_id TEXT
-                )''')
-
-    c.execute('''CREATE TABLE IF NOT EXISTS attendance (
-                    id INTEGER PRIMARY KEY AUTOINCREMENT,
-                    username TEXT,
-                    date TEXT,
-                    time TEXT,
-                    session TEXT
-                )''')
-    conn.commit()
-    return conn, c
-
-conn, c = init_db()
+    with sqlite3.connect(DB_PATH) as conn:
+        c = conn.cursor()
+        c.execute('''CREATE TABLE IF NOT EXISTS users (
+                        id INTEGER PRIMARY KEY AUTOINCREMENT,
+                        username TEXT UNIQUE,
+                        password TEXT,
+                        role TEXT,
+                        device_id TEXT
+                    )''')
+        c.execute('''CREATE TABLE IF NOT EXISTS attendance (
+                        id INTEGER PRIMARY KEY AUTOINCREMENT,
+                        username TEXT,
+                        date TEXT,
+                        time TEXT,
+                        session TEXT
+                    )''')
+        conn.commit()
+
+init_db()
 
 # Auth functions
 def register_user(username, password, role):
     try:
-        c.execute("INSERT INTO users (username, password, role) VALUES (?, ?, ?)", (username, password, role))
-        conn.commit()
+        with sqlite3.connect(DB_PATH) as conn:
+            c = conn.cursor()
+            c.execute("INSERT INTO users (username, password, role) VALUES (?, ?, ?)", (username, password, role))
+            conn.commit()
         return "✅ User registered successfully."
     except sqlite3.IntegrityError:
         return "❌ Username already exists."
@@ -42,24 +42,30 @@ def register_user(username, password, role):
 
 def login_user(username, password):
     try:
-        c.execute("SELECT * FROM users WHERE username=? AND password=?", (username, password))
-        return c.fetchone()
-    except Exception as e:
+        with sqlite3.connect(DB_PATH) as conn:
+            c = conn.cursor()
+            c.execute("SELECT * FROM users WHERE username=? AND password=?", (username, password))
+            return c.fetchone()
+    except Exception:
         return None
 
 def set_device(username, device_id):
     try:
-        c.execute("UPDATE users SET device_id=? WHERE username=?", (device_id, username))
-        conn.commit()
+        with sqlite3.connect(DB_PATH) as conn:
+            c = conn.cursor()
+            c.execute("UPDATE users SET device_id=? WHERE username=?", (device_id, username))
+            conn.commit()
         return "Device registered."
     except Exception as e:
         return f"❌ Device registration error: {str(e)}"
 
 def check_device(username, device_id):
     try:
-        c.execute("SELECT device_id FROM users WHERE username=?", (username,))
-        result = c.fetchone()
-        return result and result[0] == device_id
+        with sqlite3.connect(DB_PATH) as conn:
+            c = conn.cursor()
+            c.execute("SELECT device_id FROM users WHERE username=?", (username,))
+            result = c.fetchone()
+            return result and result[0] == device_id
     except:
         return False
 
@@ -68,8 +74,10 @@ def mark_attendance(username, session):
     try:
         date = datetime.date.today().isoformat()
         time = datetime.datetime.now().strftime("%H:%M:%S")
-        c.execute("INSERT INTO attendance (username, date, time, session) VALUES (?, ?, ?, ?)", (username, date, time, session))
-        conn.commit()
+        with sqlite3.connect(DB_PATH) as conn:
+            c = conn.cursor()
+            c.execute("INSERT INTO attendance (username, date, time, session) VALUES (?, ?, ?, ?)", (username, date, time, session))
+            conn.commit()
         return f"✅ Attendance marked at {time} for session: {session}"
     except Exception as e:
         return f"❌ Attendance error: {str(e)}"
@@ -77,8 +85,10 @@ def mark_attendance(username, session):
 # View attendance dashboard
 def view_attendance():
     try:
-        c.execute("SELECT * FROM attendance ORDER BY date DESC, time DESC")
-        records = c.fetchall()
+        with sqlite3.connect(DB_PATH) as conn:
+            c = conn.cursor()
+            c.execute("SELECT * FROM attendance ORDER BY date DESC, time DESC")
+            records = c.fetchall()
         if not records:
             return "No attendance records yet."
         return "\n".join([f"{r[1]} | {r[2]} | {r[3]} | {r[4]}" for r in records])