System.Data.DataRelation.GetParentRow C# (CSharp) Метод

        internal static DataRow GetParentRow(DataKey parentKey, DataKey childKey, DataRow childRow, DataRowVersion version)
        {
            if (!childRow.HasVersion((version == DataRowVersion.Original) ? DataRowVersion.Original : DataRowVersion.Current))
            {
                if (childRow._tempRecord == -1)
                {
                    return null;
                }
            }

            object[] values = childRow.GetKeyValues(childKey, version);
            if (IsKeyNull(values))
            {
                return null;
            }

            Index index = parentKey.GetSortIndex((version == DataRowVersion.Original) ? DataViewRowState.OriginalRows : DataViewRowState.CurrentRows);
            Range range = index.FindRecords(values);
            if (range.IsNull)
            {
                return null;
            }

            if (range.Count > 1)
            {
                throw ExceptionBuilder.MultipleParents();
            }

            return parentKey.Table._recordManager[index.GetRecord(range.Min)];
        }

        internal override void CheckConstraint(DataRow childRow, DataRowAction action)
        {
            if ((action == DataRowAction.Change ||
                 action == DataRowAction.Add ||
                 action == DataRowAction.Rollback) &&
                Table.DataSet != null && Table.DataSet.EnforceConstraints &&
                childRow.HasKeyChanged(_childKey))
            {
                // This branch is for cascading case verification.
                DataRowVersion version        = (action == DataRowAction.Rollback) ? DataRowVersion.Original : DataRowVersion.Current;
                object[]       childKeyValues = childRow.GetKeyValues(_childKey);
                // check to see if this is just a change to my parent's proposed value.
                if (childRow.HasVersion(version))
                {
                    // this is the new proposed value for the parent.
                    DataRow parentRow = DataRelation.GetParentRow(ParentKey, ChildKey, childRow, version);
                    if (parentRow != null && parentRow._inCascade)
                    {
                        object[] parentKeyValues = parentRow.GetKeyValues(_parentKey, action == DataRowAction.Rollback ? version : DataRowVersion.Default);

                        int parentKeyValuesRecord = childRow.Table.NewRecord();
                        childRow.Table.SetKeyValues(_childKey, parentKeyValues, parentKeyValuesRecord);
                        if (_childKey.RecordsEqual(childRow._tempRecord, parentKeyValuesRecord))
                        {
                            return;
                        }
                    }
                }

                // now check to see if someone exists... it will have to be in a parent row's current, not a proposed.
                object[] childValues = childRow.GetKeyValues(_childKey);
                if (!IsKeyNull(childValues))
                {
                    Index parentIndex = _parentKey.GetSortIndex();
                    if (!parentIndex.IsKeyInIndex(childValues))
                    {
                        // could be self-join constraint
                        if (_childKey.Table == _parentKey.Table && childRow._tempRecord != -1)
                        {
                            int lo = 0;
                            for (lo = 0; lo < childValues.Length; lo++)
                            {
                                DataColumn column = _parentKey.ColumnsReference[lo];
                                object     value  = column.ConvertValue(childValues[lo]);
                                if (0 != column.CompareValueTo(childRow._tempRecord, value))
                                {
                                    break;
                                }
                            }
                            if (lo == childValues.Length)
                            {
                                return;
                            }
                        }
                        throw ExceptionBuilder.ForeignKeyViolation(ConstraintName, childKeyValues);
                    }
                }
            }
        }