public void Add()
{
DataRelationCollection drcol = _dataset.Relations;
DataColumn parentCol = _dataset.Tables["Customer"].Columns["custid"];
DataColumn childCol = _dataset.Tables["Order"].Columns["custid"];
DataRelation dr = new DataRelation("CustOrder", parentCol, childCol);
drcol.Add(dr);
Assert.Equal("CustOrder", drcol[0].RelationName);
drcol.Clear();
drcol.Add(parentCol, childCol);
Assert.Equal(1, drcol.Count);
drcol.Clear();
drcol.Add("NewRelation", parentCol, childCol);
Assert.Equal("NewRelation", drcol[0].RelationName);
drcol.Clear();
drcol.Add("NewRelation", parentCol, childCol, false);
Assert.Equal(1, drcol.Count);
drcol.Clear();
drcol.Add("NewRelation", parentCol, childCol, true);
Assert.Equal(1, drcol.Count);
drcol.Clear();
}