DataTable Constraints

[M Hyde]

What is the difference between adding a primary
key/unique constraint to a DataTable object using the
Constraint.Add method vs. using the PrimaryKey property
of the DataTable or Unique property of the DataColumn? Is
it redundant to use both? If so which method is
preferable?

 

[Steven Bras [MS]]

If the column is a primary key, then use the PrimaryKey property; if the
column is not the key, but requires uniqueness, then add the constraint.
Simply requiring uniqueness is not the same as being a primary key, and the
framework will look at this property when it requires primary key
information on the table.

Steven Bras, MCSD
Microsoft Developer Support/Data Access Technologies

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