The query is invalid after the newly added database table field in TP3.2, the code is correct, and there is no error, how can this be done?

I believe that many beginners like me will encounter some weird things when doing tp development. A new field is added to a table in the database, and then this part of the condition code is added to the query condition.
It is very strange that after refreshing the page, this code seems to have no effect on the query results. Later, after a long time of troubling, I learned that the TP framework cache should be actively cleared after the database structure changes.
Solution: Delete the corresponding data table file in runtime/Data/_fields/xx and it will be OK.