diff --git a/src/calc.py b/src/calc.py
index 1111111..2222222 100644
--- a/src/calc.py
+++ b/src/calc.py
@@ -15,7 +15,7 @@ def divide(a, b):
-    return a / b
+    if b == 0:
+        raise ValueError("除数不能为 0")
+    return a / b
 
diff --git a/src/user.py b/src/user.py
index 3333333..4444444 100644
--- a/src/user.py
+++ b/src/user.py
@@ -10,7 +10,7 @@ def find_user(name):
-    sql = f"SELECT * FROM users WHERE name='{name}'"
-    return cursor.execute(sql)
+    return cursor.execute("SELECT * FROM users WHERE name=%s", (name,))
