Computer room charge system-upper and lower machine

Computer room charge system of the upper and lower machine design to the query table, calculate the amount, update the table and other parts of the content. Explain in detail the logical understanding of the upper and lower machine.

on the machine

Logic Analysis:

Down machine

Logic Analysis:

According to the logical steps to design the code, in the upper and lower form the most difficult to understand is the amount of the calculation part of the calculation of the amount of the next machine can follow the following ideas to operate:

1. Use the DateDiff function to calculate consumption time

2. Compare time to select the calculation method of the amount (in the underlying data table there are settings for time and different user rates)

3. Update the consumption amount and balance to the corresponding table (the revision status is checkout)

4. Delete a record in the on-machine