Fix db error

app.py

@@ -214,6 +214,15 @@ def main():
     #         db = FAISS.from_documents(sp_docs, embeddings)
     #         # db.save_local(DB_FAISS_UPLOAD_PATH)
     #         # st.write(f"Your model is already store in {DB_FAISS_UPLOAD_PATH}")
+
+    llm = load_llama2_llamaCpp()
+    qa_prompt = set_custom_prompt()
+    memory = ConversationBufferWindowMemory(k = 0, return_messages=True,  input_key= 'question', output_key='answer', memory_key="chat_history")
+    #memory = ConversationBufferMemory(memory_key="chat_history", return_messages=True)
+    doc_chain = load_qa_chain(llm, chain_type="stuff", prompt = qa_prompt)
+    question_generator = LLMChain(llm=llm, prompt=CONDENSE_QUESTION_PROMPT)
+
+    
     uploaded_file = st.file_uploader('Choose your .pdf file', type="pdf")
     print(uploaded_file)
     if uploaded_file is not None:
@@ -223,14 +232,6 @@ def main():
         for page in pdf_reader.pages:
             text += page.extract_text()
         db = FAISS.from_texts(text, embeddings)
-
-    llm = load_llama2_llamaCpp()
-    qa_prompt = set_custom_prompt()
-    memory = ConversationBufferWindowMemory(k = 0, return_messages=True,  input_key= 'question', output_key='answer', memory_key="chat_history")
-    #memory = ConversationBufferMemory(memory_key="chat_history", return_messages=True)
-    doc_chain = load_qa_chain(llm, chain_type="stuff", prompt = qa_prompt)
-    question_generator = LLMChain(llm=llm, prompt=CONDENSE_QUESTION_PROMPT)
-    if db is not None :
         qa_chain = ConversationalRetrievalChain(
             retriever =db.as_retriever(search_type="similarity_score_threshold", search_kwargs={'k':3,  "score_threshold": 0.7}), 
             question_generator=question_generator,