c# - DataTable 上的 UNIQUE 约束

Question

我可以在 DataTable 上有一个集群 key 吗？在 C# 中？

我的代码中要求对 3 列的可能组合具有唯一性进行约束.....

Answer 1

您真正需要的是一个唯一约束 在您的 DataTable .群集键是 SQL Server 磁盘功能，不适用于 DataTable .

退房 MSDN doc on DataTable constraints :

The UniqueConstraint object, which can be assigned either to a single column or to an array of columns in a DataTable, ensures that all data in the specified column or columns is unique per row. You can create a unique constraint for a column or array of columns by using the UniqueConstraint constructor.

所以尝试这样的事情:

// this is your DataTable
DataTable custTable ;

// create a UniqueConstraint instance and set its columns that should make up
// that uniqueness constraint - in your case, that would be a set of *three*
// columns, obviously! Adapt to your needs!
UniqueConstraint custUnique = 
   new UniqueConstraint(new DataColumn[] { custTable.Columns["CustomerID"], 
                                           custTable.Columns["CompanyName"] });

// add unique constraint to the list of constraints for your DataTable
custTable.Constraints.Add(custUnique);

这应该对你有用!