Flask RESTless delete multiple primary key

Question

I've a little problem with Flask RESTless, maybe you can help me :)

I have some tables in my SQL (and SQLAlchemy) that are results of N..N relation, and their primary Keys are the sum of two columns. For example

Table 1 Key / Table 2 Key / Some data
0             0             Bla
0             1             Blabla
1             0             Morebla
1             1             Silenceisgolden

If I use GET verb with an ID, Example 0, RESTless use only "Table 1 Key" and return me 0,0,Bla.

I can use the query Language (?q=) and get both 0,0 and 0,1.

Question is: how I can select only one with PATCH or DELETE verb? I can only DELETE or PATCH 0,0

Hope this question is clear :)

Many thanks!

Answer 1

I've had a similar issue recently. The problem is that flask-restless likes to assume that primary keys are non-composites.

However, there is perfectly fine work around. First off, you need to enable multi-DELETE and multi-PATCH for your endpoint:

 manager.create_api(                                                              
      Your_Composite_Model,     # flask-sqlalchemy model class                                                                 
      methods=['GET', 'POST', 'DELETE', 'PATCH'],                                  
      allow_delete_many=True,                                                      
      allow_patch_many=True) 

This change allows you to delete or patch items in the table using flask-restless' query parameter, which you can use to filter for the exact row you wish to delete.

Below is a python script using the requests library that deletes the second row (and only the second row) in your above composite table:

import requests                                                                  
import json                                                                      

url = 'http://127.0.0.1:5000/api/your_composite_model'                              
headers = {'Content-Type': 'application/json'}                                   

filters = [                                                                      
    dict(name='table_1_key', op='eq', val='0'),                            
    dict(name='table_2_key', op='eq', val='1'),                    
]                                                                                

params = dict(q=json.dumps(dict(filters=filters)))                               

response = requests.delete(url, params=params, headers=headers)                                                                                     
print(response.json())                                                           

~

The output should be: {u'num_deleted': 1}