Gets or sets if a duplicate key is possible in the source.
context.BulkMerge(list, options => options.AllowDuplicateKeys = true);
In a rare scenario such as importing a file, a key may be used in multiple rows.
In some provider such as SQL Server, the statement created by our library (
Merge) makes it impossible to use with some duplicate keys.
By enabling this option, only the latest key is used instead.