Ask bosses, how to use the flask - sqlalchemy query a database a field contains a keyword-CodePudding

Small white the first attempt to use flask - sqlalchemy SQL operation
The food in the table tags are a comma separated string, example: blue, guitar
I want to check whether the tags field in a database contains a keyword, such as in the table all the price of the item contains blue tags found out
I tried to filter used in, but an error AttributeError: 'NoneType' object has no attribute 'in_'

 class Food (the Model) : 
__tablename__='food' 

Id=db. The Column (db. The Integer, primary_key=True) 
Cat_id=db. The Column (db. The Integer, nullable=False, server_default=the FetchedValue ()) 
Name=db. The Column (the String (100), the nullable=False, server_default=the FetchedValue ()) 
Price=db. The Column (the Numeric (10, 2) and nullable=False) 
Main_image=db. The Column (the String (100), the nullable=False, server_default=the FetchedValue ()) 
The summary=db. The Column (the String (10000), the nullable=False, server_default=the FetchedValue ()) 
Stock=db. The Column (db. The Integer, nullable=False, server_default=the FetchedValue ()) 
Tags=db. The Column (the String (200), the nullable=False, server_default=the FetchedValue ()) 
Status=db. The Column (db. The Integer, nullable=False, server_default=the FetchedValue ()) 
Updated_time=db. The Column (the DateTime, nullable=False, server_default=the FetchedValue ()) 
Created_time=db. The Column (the DateTime, nullable=False, server_default=the FetchedValue ()) 


Def query_price (self, goodsname) : 

Obj=self. Query. The filter (self) tags) in_ (goodsname)). The first () 
Return obj. Price

Here is my query

 goods_price=the Food (). Query_price (data_name)

Inquire of bosses have a good way to solve