## Filtering responses

    The API allows for some advanced response filtering using a json based query syntax that 

    can be added as a query parameter, `q=` or in the request body.

    For simple field equality matches we can use `{ "fieldname": "value" }` where the fieldname

    matches one of the fields as described in the particular endpoints response object.

    We can refine that with more complex matching clauses by nesting a the clause into the 

    object; `{ "fieldname": { "clause": "value" } }`.

    Available matching clauses include ">", "<", ">=", "<=", "-like", and "-not_like".

    We can filter on multiple fields by adding them to the JSON respresentation. Adding at `HASH` 

    level will result in an 'AND' query, whilst combinding them in an `ARRAY` wilth result in an

    'OR' query: `{ "field1": 'value2', "field2": "value2" }` will filter the response to only those

    results with both field1 containing value2 AND field2 containing value2 for example.

    ### Examples

    The following request would return any patron with firstname "Henry" and lastname "Acevedo";

    `curl -u koha:koha --request GET 'http://127.0.0.1:8081/api/v1/patrons/' --data-raw '{ "surname": "Acevedo", "firstname": "Henry" }'`

    The following request would return any patron whose lastname begins with "Ace";

    `curl -u koha:koha --request GET 'http://127.0.0.1:8081/api/v1/patrons/' --data-raw '{ "surname": { "-like": "Ace%" }'`

    The following request would return any patron whilse lastname is 'Acevedo' OR 'Bernardo'

    `curl -u koha:koha --request GET 'http://127.0.0.1:8081/api/v1/patrons/' --data-raw '{ "surname": [ "Acevedo", "Bernardo" ] }'`