Fix: Optimize Prompts and Regex for use_sql() (#11148)

### What problem does this PR solve?

Fix: Optimize Prompts and Regex for use_sql() #11127 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/db/services/dialog_service.py

@@ -619,7 +619,12 @@ def chat(dialog, messages, stream=True, **kwargs):
 
 
 def use_sql(question, field_map, tenant_id, chat_mdl, quota=True, kb_ids=None):
-    sys_prompt = "You are a Database Administrator. You need to check the fields of the following tables based on the user's list of questions and write the SQL corresponding to the last question."
+    sys_prompt = """
+You are a Database Administrator. You need to check the fields of the following tables based on the user's list of questions and write the SQL corresponding to the last question. 
+Ensure that:
+1. Field names should not start with a digit. If any field name starts with a digit, use double quotes around it.
+2. Write only the SQL, no explanations or additional text.
+"""
     user_prompt = """
 Table name: {};
 Table of database fields are as follows:
@@ -640,6 +645,7 @@ Please write the SQL, only SQL, without any other explanations or text.
         sql = re.sub(r".*select ", "select ", sql.lower())
         sql = re.sub(r" +", " ", sql)
         sql = re.sub(r"([;；]|```).*", "", sql)
+        sql = re.sub(r"&", "and", sql)
         if sql[: len("select ")] != "select ":
             return None, None
         if not re.search(r"((sum|avg|max|min)\(|group by )", sql.lower()):