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How can avoid duplicate fields in a virtual table? There is no keyfields property and lookup and locate don't work while editing a record.

Hello,

I could not reproduce the problem.
Please send me a complete small sample to andreyz*devart*com to demonstrate the problem.

Let me explain a bit more.

Supose you want to add a row with a field that requires unique values. How do you check that the field does not contain data that is already in the dataset?

For example you have a table T with Field F, you want to be sure Field F does not have a value already present in the table T before adding the row to the table. How do you check? If you are editing the row and call Locate, a scroll event occurs that forces the record to be posted, and VirtualTable does not have a Keyfields property that will disallow the row to be inserted with the duplicate value.

The TVirtualTable component doesn't support such functionality. But you can write the code that checks TVirtualTable for duplicate records using the AfterPost event and the Locate method.