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Solution:
None of your selects have names, so they won't be serialised. This is a fundamental rule of how HTML forms work, which you need to ensure you are familiar with. The name attribute controls the name which the parameter will have when it is sent to the server.
E.g. you need to have something like
<select name="quand" class="form-control" id="select_quand">
And have similar on each form element you want to submit.
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