Duplicate entries over multiple fileds

[Clarkeyboy]

Hi, I am creating a database system for a school project and I'm fairly new to Access:
I am creating a dentist booking system for a fictional dentist company...
I have created a form to add new appointments but I do not want to double book times etc...
I have 4 dentists with 15 minute appointment slots available. How would I prevent double booking the same dentist at the same time?
Any help is much appreciated.

[isladogs]

One way of doing it is to have a composite primary key using both dentist name and appointment date/times
That will prevent the combination of values being repeated

[Clarkeyboy]

Thanks, If I were to do that, would the composite primary key prevent all duplicate values?
For example, If dentist 1 had an appointment at 10:00 on 22nd May, would it allow me to have an appointment at the exact same time with dentist 2?
Or would the composite key only prevent duplicates if every field was the same?

[isladogs]

Thanks, If I were to do that, would the composite primary key prevent all duplicate values?
For example, If dentist 1 had an appointment at 10:00 on 22nd May, would it allow me to have an appointment at the exact same time with dentist 2?
Or would the composite key only prevent duplicates if every field was the same?

Primary keys prevent duplicates
Having a composite PK would only prevent duplicates of both fields.
So you can still make appointments for other dentists at that time or the same dentist at any other time

[Clarkeyboy]

Okay, but when i set the index to "Yes(No duplicates)" I receive the following:
The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship. (Error 3022)

[isladogs]

Okay, but when i set the index to "Yes(No duplicates)" I receive the following:
The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship. (Error 3022)

That's because you already have duplicates so you need to identify and remove those
One way to do so is by using the wizard to create a duplicates query.

But if you select both fields and then click Primary Key in the ribbon, it should automatically set both fields to 'Yes, no duplicates'

[June7]

The two fields do not have to be the key, just set them as a compound index. Autonumber field can still be primary key.

[isladogs]

The two fields do not have to be the key, just set them as a compound index. Autonumber field can still be primary key.

True but the OP still needs to remove the existing duplicates

[Clarkeyboy]

Thank you both!!! I ended up trying that compound unique index (Was quite easy in the end)
Much appreciated