C#DataSet.Relations:如何使用DataSet关系？

DataSet dataSet = new DataSet();

DataTable parentTable = new DataTable("ParentTable");
DataTable childTable = new DataTable("ChildTable");

dataSet.Tables.Add(parentTable);
dataSet.Tables.Add(childTable);

parentTable.Columns.Add("ParentID", typeof(int));
parentTable.Columns.Add("ParentName", typeof(string));

childTable.Columns.Add("ChildID", typeof(int));
childTable.Columns.Add("ChildName", typeof(string));
childTable.Columns.Add("ParentID", typeof(int));

DataColumn parentColumn = parentTable.Columns["ParentID"];
DataColumn childColumn = childTable.Columns["ParentID"];

DataRelation relation = new DataRelation("ParentChildRelation", parentColumn, childColumn);
dataSet.Relations.Add(relation);

// 使用DataSet.Load方法填充数据
dataSet.Load(dataReader, LoadOption.OverwriteChanges, parentTable, childTable);