The database contain three different categories and they are temperature, wind speed, and date.

And my question is how can I get all the number from the temperature section
by using data environment?

I don't get it!

I can only show the database through table or retrieve data from the database when something was type in. For example, I type in the date inside a text box and search for the temperature on that date.

However, I want to draw a line graph that shows the history temperature and I want to retrieve all the number for temperature from the database when a button is press.