diff --git a/be/app.py b/be/app.py
index eb9e897..fd76f14 100644
--- a/be/app.py
+++ b/be/app.py
@@ -18,7 +18,7 @@ db = pymysql.connect(host='192.168.0.89',
                      user='root',
                      password='2020yunjisuan!',
                      db='shuishan',
-                     charset='utf8')
+                     charset='utf8mb4')
 
 
 @app.route('/get-problem-items/')
@@ -77,8 +77,13 @@ def get_problem_description(_id: str):
 def case_test_():
     pid: str = request.json.get("pid")
     code: str = request.json.get("code")
+
+    pid = str(pid)
+    code = str(code)
     with open('wulin.txt', 'w', encoding='utf-8', newline='') as f:
-        f.write(pid)
+        f.write(pid+"\n")
+        f.write(code + "\n")
+
     f.close()
     results = testcase.submit_handler(code, pid, 'C')
 
@@ -108,8 +113,11 @@ def check_logic_error():
 def submit():
     pid: str = request.json.get("pid")
     code: str = request.json.get("code")
+    pid = str(pid)
+    code = str(code)
     with open('wulin2.txt', 'w', encoding='utf-8', newline='') as f:
-        f.write(pid)
+        f.write(pid + "\n")
+        f.write(code + "\n")
     f.close()
     results = mysubmit.submit_handler(code, pid, 'C')