How to Upload the Data automatically daily.

How exactly do you receive this data?
- You could create a dedicated email address, and a small service that check that mailbox, and if a mail with those data arrives, after verifying it's liability, could process it.
- If your data provider is able to provide you the data this way, you could fetch your data from an external url from time to time, and process it.

This would be a real automatism in your case. But I dont know how you imagine your automatism.

You want to automatically post the form on the page right after you selected the file? Than you can use JavaScript like here:

<form action="upload.php" method="post">
<input type="file" onchange="this.form.submit()" name="myFile"/>
</form>

I don't know how you upload data, upload the .txt file or the Text inside it?
if you're sending the text inside, You can Use a Windows Service, Define a timer and check for new .txt files,use File.ReadAllText and store it into your Database.
if you tell more details we can help you more

You can create a windows service which will execute at specified time, which will call your upload function from the specified page.