System.Data.ForeignKeyConstraint.CascadeDelete C# (CSharp) Метод

        internal void CascadeDelete(DataRow row)
        {
            if (-1 == row._newRecord)
            {
                return;
            }

            object[] currentKey = row.GetKeyValues(_parentKey, DataRowVersion.Current);
            if (IsKeyNull(currentKey))
            {
                return;
            }

            Index childIndex = _childKey.GetSortIndex();
            switch (DeleteRule)
            {
                case Rule.None:
                    {
                        if (row.Table.DataSet.EnforceConstraints)
                        {
                            // if we're not cascading deletes, we should throw if we're going to strand a child row under enforceConstraints.
                            Range range = childIndex.FindRecords(currentKey);
                            if (!range.IsNull)
                            {
                                if (range.Count == 1 && childIndex.GetRow(range.Min) == row)
                                    return;

                                throw ExceptionBuilder.FailedCascadeDelete(ConstraintName);
                            }
                        }
                        break;
                    }

                case Rule.Cascade:
                    {
                        object[] key = row.GetKeyValues(_parentKey, DataRowVersion.Default);
                        Range range = childIndex.FindRecords(key);
                        if (!range.IsNull)
                        {
                            DataRow[] rows = childIndex.GetRows(range);

                            for (int j = 0; j < rows.Length; j++)
                            {
                                DataRow r = rows[j];
                                if (r._inCascade)
                                    continue;
                                r.Table.DeleteRow(r);
                            }
                        }
                        break;
                    }

                case Rule.SetNull:
                    {
                        object[] proposedKey = new object[_childKey.ColumnsReference.Length];
                        for (int i = 0; i < _childKey.ColumnsReference.Length; i++)
                            proposedKey[i] = DBNull.Value;
                        Range range = childIndex.FindRecords(currentKey);
                        if (!range.IsNull)
                        {
                            DataRow[] rows = childIndex.GetRows(range);
                            for (int j = 0; j < rows.Length; j++)
                            {
                                // if (rows[j].inCascade)
                                //    continue;
                                if (row != rows[j])
                                    rows[j].SetKeyValues(_childKey, proposedKey);
                            }
                        }
                        break;
                    }
                case Rule.SetDefault:
                    {
                        object[] proposedKey = new object[_childKey.ColumnsReference.Length];
                        for (int i = 0; i < _childKey.ColumnsReference.Length; i++)
                            proposedKey[i] = _childKey.ColumnsReference[i].DefaultValue;
                        Range range = childIndex.FindRecords(currentKey);
                        if (!range.IsNull)
                        {
                            DataRow[] rows = childIndex.GetRows(range);
                            for (int j = 0; j < rows.Length; j++)
                            {
                                // if (rows[j].inCascade)
                                //    continue;
                                if (row != rows[j])
                                    rows[j].SetKeyValues(_childKey, proposedKey);
                            }
                        }
                        break;
                    }
                default:
                    {
                        Debug.Assert(false, "Unknown Rule value");
                        break;
                    }
            }
        }