Fix bugs in api and add examples (#3353)

### What problem does this PR solve?

Fix bugs in api.
Add simple examples for api.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

api/apps/sdk/dataset.py

     """
     id = request.args.get("id")
     name = request.args.get("name")
-    kbs = KnowledgebaseService.query(id=id, name=name, status=1)
-    if not kbs:
-        return get_error_data_result(message="The dataset doesn't exist")
-    for kb in kbs:
-        if not KnowledgebaseService.accessible(kb_id=kb.id,user_id=tenant_id):
-            return get_error_data_result(message=f"You don't own the dataset {kb.id}")
+    if id:
+        kbs = KnowledgebaseService.get_kb_by_id(id,tenant_id)
+        if not kbs:
+            return get_error_data_result(f"You don't own the dataset {id}")
+    if name:
+        kbs = KnowledgebaseService.get_kb_by_name(name,tenant_id)
+        if not kbs:
+            return get_error_data_result(f"You don't own the dataset {name}")
     page_number = int(request.args.get("page", 1))
     items_per_page = int(request.args.get("page_size", 30))
     orderby = request.args.get("orderby", "create_time")

api/db/services/knowledgebase_service.py

             return False
         return True
 
+    @classmethod
+    @DB.connection_context()
+    def get_kb_by_id(cls, kb_id, user_id):
+        kbs = cls.model.select().join(UserTenant, on=(UserTenant.tenant_id == Knowledgebase.tenant_id)
+            ).where(cls.model.id == kb_id, UserTenant.user_id == user_id).paginate(0, 1)
+        kbs = kbs.dicts()
+        return list(kbs)
+
+    @classmethod
+    @DB.connection_context()
+    def get_kb_by_name(cls, kb_name, user_id):
+        kbs = cls.model.select().join(UserTenant, on=(UserTenant.tenant_id == Knowledgebase.tenant_id)
+            ).where(cls.model.name == kb_name, UserTenant.user_id == user_id).paginate(0, 1)
+        kbs = kbs.dicts()
+        return list(kbs)
+
     @classmethod
     @DB.connection_context()
     def accessible4deletion(cls, kb_id, user_id):

docs/references/http_api_reference.md

      --url http://{address}/api/v1/datasets \
      --header 'Content-Type: application/json' \
      --header 'Authorization: Bearer <YOUR_API_KEY>' \
-     --data '{"ids": ["test_1", "test_2"]}'
+     --data '{
+     "ids": ["test_1", "test_2"]
+     }'
 ```
 
 #### Request parameters
      --header 'Authorization: Bearer <YOUR_API_KEY>' \
      --data '
      {
-          "name": "updated_dataset",
+          "name": "updated_dataset"
      }'
 ```
 
      --data '
      {   
           "content": "ragflow123",  
-          "important_keywords": [],   
+          "important_keywords": []  
      }'
 ```
 

docs/references/python_api_reference.md

 session = assistant.create_session()    
 
 print("\n==================== Miss R =====================\n")
-print(assistant.get_prologue())
+print("Hello. What can I do for you?")
 
 while True:
     question = input("\n==================== User =====================\n> ")

example/http/simple_example.sh

+#
+#  Copyright 2024 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+# Create a dataset
+echo -e "\n-- Create a dataset"
+curl --request POST \
+     --url http://localhost:9380/api/v1/datasets \
+     --header 'Content-Type: application/json' \
+     --header 'Authorization: Bearer ragflow-IzZmY1MGVhYTBhMjExZWZiYTdjMDI0Mm' \
+     --data '{
+      "name": "test"
+      }'
+
+# Update the dataset
+echo -e "\n-- Update the dataset"
+curl --request PUT \
+     --url http://localhost:9380/api/v1/datasets/2e898768a0bc11efb46a0242ac120006 \
+     --header 'Content-Type: application/json' \
+     --header 'Authorization: Bearer ragflow-IzZmY1MGVhYTBhMjExZWZiYTdjMDI0Mm' \
+     --data '
+     {
+          "name": "updated_dataset"
+     }'
+
+# List datasets
+echo -e "\n-- List datasets"
+curl --request GET \
+     --url http://127.0.0.1:9380/api/v1/datasets \
+     --header 'Authorization: Bearer ragflow-IzZmY1MGVhYTBhMjExZWZiYTdjMDI0Mm'
+
+# Delete datasets
+echo -e "\n-- Delete datasets"
+curl --request DELETE \
+     --url http://localhost:9380/api/v1/datasets \
+     --header 'Content-Type: application/json' \
+     --header 'Authorization: Bearer ragflow-IzZmY1MGVhYTBhMjExZWZiYTdjMDI0Mm' \
+     --data '{
+     "ids": ["301298b8a0bc11efa0440242ac120006"]
+     }'

example/sdk/simple_example.py

+#
+#  Copyright 2024 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+'''
+The example is about CRUD operations (Create, Read, Update, Delete) on a dataset.
+'''
+
+from ragflow_sdk import RAGFlow
+import sys
+
+HOST_ADDRESS = "http://127.0.0.1"
+API_KEY = "ragflow-IzZmY1MGVhYTBhMjExZWZiYTdjMDI0Mm"
+
+try:
+    # create a ragflow instance
+    ragflow_instance = RAGFlow(api_key=API_KEY, base_url=HOST_ADDRESS)
+
+    # crate a dataset instance
+    dataset_instance = ragflow_instance.create_dataset(name="dataset_instance")
+
+    # update the dataset instance
+    updated_message = {"name":"updated_dataset"}
+    updated_dataset = dataset_instance.update(updated_message)
+
+    # get the dataset (list datasets)
+    dataset_list = ragflow_instance.list_datasets(id=dataset_instance.id)
+    dataset_instance_2 = dataset_list[0]
+    print(dataset_instance)
+    print(dataset_instance_2)
+
+    # delete the dataset (delete datasets)
+    to_be_deleted_datasets = [dataset_instance.id]
+    ragflow_instance.delete_datasets(ids=to_be_deleted_datasets)
+
+    print("test done")
+    sys.exit(0)
+
+except Exception as e:
+    print(str(e))
+    sys.exit(-1)
+
+