Prevent Duplicate in table.

[maabbas]

Hello everyone,

Once again me bring you another question. I have a table called Attendance there are 4 fields in it.

Attend_ID
Attend_Date
ID_Employee
ID_Point.

There is only one entry of specific employee in one day. for example on 07/28/2015 Employee id 2070 only can have one entry.

is there any way I can prevent user to enter duplicate value.

Thanks

 

[Joe4]

You can create a Composite Primary Key based on these two fields (those not allowing duplicates based on these two fields).
Or, if you already have something like an Autonumber field as the Primary Key, you can just create a Composite Unique Index.
See: How to create a composite unique index (not as a primary key) in MS Access

 

[maabbas]

Thanks Joe4 for your reply, I follow the instruction on link but unable to save Indexes, I am not sure why.
I used Indexes as follow

Attend_ID Key Autonumber Unique ID No Duplicate
Attend_Date Short Date No Duplicate
ID_Employee Number No Duplicate

 

[Joe4]

Is your data table in Access, or link to some other data source?
Which version of Access are you using?