Microsoft Access Booking System Macro

Question

I want to create a booking system on access. Unfortunately I cannot provide you with the database link until my account gets verified. Here is the macro action sequence.
<?xml version="1.0" encoding="UTF-16" standalone="no"?>
<UserInterfaceMacros xmlns="http://schemas.microsoft.com/office/accessservices/2009/11/application"><UserInterfaceMacro MinimumClientDesignVersion="14.0.0000.0000"><Statements><ConditionalBlock><If><Condition>=DLookUp("Client_ID","Appointment","Client_ID=Forms![Booking
Screen]![Clientcombo] AND [Time]=Forms![Booking Screen]![Timecombo] AND [Date]=Forms![Booking Screen]![Date]") Is Not Null</Condition><Statements><Action Name="MessageBox"><Argument Name="Message">The client
is already booked for this time slot.</Argument><Argument Name="Title">Client already booked</Argument></Action><Action Name="SetLocalVar"><Argument Name="Name">BookingOK</Argument><Argument
Name="Expression">"No"</Argument></Action></Statements></If><Else><Statements/></Else></ConditionalBlock><Action Name="SetLocalVar"><Argument Name="Name">BookingOK</Argument><Argument
Name="Expression">"OK"</Argument></Action><ConditionalBlock><If><Condition>=DLookUp("MeetingRoom_ID","Appointment","MeetingRoom_ID=Forms![Booking Screen]![Roomcombo] AND [Time]=Forms![Booking
Screen]![Timecombo] AND [Date]=Forms![Booking Screen]![Date]") Is Not Null</Condition><Statements><Action Name="MessageBox"><Argument Name="Message">This meeting room is already booked for this time slot.</Argument><Argument
Name="Title">Meeting room already booked</Argument></Action><Action Name="SetLocalVar"><Argument Name="Name">BookingOK</Argument><Argument Name="Expression">"No"</Argument></Action></Statements></If><Else><Statements/></Else></ConditionalBlock><ConditionalBlock><If><Condition>=DLookUp("Employee_ID","Appointment","Employee_ID=Forms![Booking
Screen]![Employeecombo] AND [Time]=Forms![Booking Screen]![Timecombo] AND [Date]=Forms![Booking Screen]![Date]") Is Not Null</Condition><Statements><Action Name="MessageBox"><Argument Name="Message">The solicitor
is already booked for this time slot.</Argument><Argument Name="Title">Solicitor already booked</Argument></Action><Action Name="SetLocalVar"><Argument Name="Name">BookingOK</Argument><Argument
Name="Expression">"No"</Argument></Action></Statements></If><Else><Statements/></Else></ConditionalBlock><ConditionalBlock><If><Condition>[LocalVars]![BookingOK]="OK"</Condition><Statements><Action
Name="MessageBox"><Argument Name="Message">This booking can be made.</Argument><Argument Name="Title">Booking confirmed</Argument></Action><Action Name="OpenQuery"><Argument
Name="QueryName">Booking query</Argument></Action></Statements></If></ConditionalBlock></Statements></UserInterfaceMacro></UserInterfaceMacros>
The macro basically searches the appointments table to ensure that the client, employee or meeting room isn't booked on the date and time input by the user. This is to prevent double bookings. Although the macro does work somewhat it is not fully functional.
It checks and identifies when there are double bookings and it clearly displays the message however it proceeds to state that a booking is available when it shouldn't be. If anyone can also tell me how to display the appointments in the form of a weekly or
monthly calendar that would be extremely helpful. I also want to have reminders popping up about 1 week before any appointment. If anyone could help me with any of these issues that would be greatly appreciated.
Kind regards
Harry

Answer 1

You might like to take a look at Reservations.zip in my public databases folder at:
https://onedrive.live.com/?cid=44CC60D7FEA42912&id=44CC60D7FEA42912!169
If you have difficulty opening the link copy its text (NB, not the link location) and paste it into your browser's address bar.
This little demo file illustrates a basic methodology for room reservation systems and similar.  It uses VBA throughout, not macros, but the logic which is behind the code might be helpful to you, or, unless you are developing a web database and consequently
specifically need to use macros, you can use VBA in your own application.
If you open the main room reservations form you'll see that, in the subform, in the room number combo box the available rooms listed after inserting the 'from' and 'to' dates are only those vacant in the entire date range.  This is done by calling the
WithinDateRange function in the control's RowSource query.  This function embodies the standard simple logic for determining intersecting ranges.
The subform will also reject a booking where the occupant is already booked into another room within the date range of the currently attempted booking.  This is done by means of code in the subform's BeforeUpdate event procedure, again calling the WithinDateRange
function.
While my demo uses dates, the logic is of course exactly the same for date/time values.  In Access a 'date value' is in fact merely a date/time value with a zero time of day element, i.e. midnight at the start of the day in question.
Ken Sheridan, Stafford, England