Queries fail when an empty array is passed

[thanhnguyen2187]

Hi!

On testing #38, I found a subtle bug where ws4sqlite would not be able to process if an empty array is passed. In more details:

# start the server
ws4sqlite --db /tmp/crypta.db

# sending request
curl \
    -X POST \
    --header 'Content-Type: application/json' \
    --data @/tmp/data.json \
    --fail-with-body \
    127.0.0.1:12321/crypta \
| jq

Where /tmp/data's content is:

{
    "transaction": [
        {
            "query": "SELECT 1",
            "values": []
        }
    ]
}

The response is:

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   257  100   156  100   101   420k   272k --:--:-- --:--:-- --:--:--  250k
curl: (22) The requested URL returned error: 400
{
  "reqIdx": -1,
  "error": "in parsing body: json: cannot unmarshal array into Go struct field requestItem.transaction.values of type map[string]json.RawMessage"
}

A workaround for this is to change from empty array [] to empty object/dictionary {}.

I'll see if I can help with this in another PR.

Thanks!

---

EDIT: this is expected. ws4sqlite differs from sqliterg in this regard 😅.

[thanhnguyen2187]

If the query needs to be parametrized, named parameters can be defined in the statement using SQLite (e.g. :id or @id), and the proper values for them must be specified here. You can specify values that do not match a parameter; they'll be ignored.

https://germ.gitbook.io/ws4sqlite/documentation/requests