I want to use NI No as the unique identifier for customer. So when the user enter customer data into customer form, they must enter NI No first. If the value of NI No they entered is duplicate, that means this customer has existed on the database, then the warning message should be displayed and the action of data entry will be cancelled.
How to realise this function?
In the table design, I have designed the index of NI No is Not Duplicates. So After the user enter data into all fields, the message shows it is fault and can not save the record this time. It will waste lots of time. What I want is to show the warning message upon the duplicate NI No is entered, not until all fields are entered.
Many thanks in advance!
How to realise this function?
In the table design, I have designed the index of NI No is Not Duplicates. So After the user enter data into all fields, the message shows it is fault and can not save the record this time. It will waste lots of time. What I want is to show the warning message upon the duplicate NI No is entered, not until all fields are entered.
Many thanks in advance!