예제 #1
0
        /// <summary>
        /// Answers whether the data in the column named columnName in the child table all have the same value.
        /// </summary>
        /// <param name="ds">The Dataset</param>
        /// <param name="relationName">The index of the parent row which is being considered for this check.</param>
        /// <param name="parentRowIndex">The name of the relation between the parent and child table.  </param>
        /// <param name="columnName">The DataColumn to look for</param>
        /// <param name="ignoreNullCells">Should we ignore NULL cells</param>
        /// <returns></returns>
        public static bool columnInChildRowsHaveSameValue(DataSet ds, string relationName, int parentRowIndex,
                                                          string columnName, bool ignoreNullCells)
        {
            bool haveSameValue = true;

            DataRelation dataRelation = ds.Relations[relationName];

            // get the child rows which correspond to the parent row

            DataRow[] childRowsArray = dataRelation.ParentTable.Rows[parentRowIndex].GetChildRows(relationName);

            IEnumerator childRowsCollection = childRowsArray.GetEnumerator();

            if (childRowsArray.Length < 1)
            {
                // special case
                // (from bug 267)
                // it appears that if one tries to group by one or more columns and all child rows happen to have DBNull in the corresponding
                // columns that GetChildRows will not find any matching child rows (when it seems that it should have returned all rows)
                // Under these circumstances we'll try to do a select distinct on the grouping columns and, if we get exactly one data item
                // back, we'll set the childRowsArray equal to all of the rows in the child table.
                // a better solution would be to somehow involve the GetChildRows call directly but I didn't find anything in my
                // web searching which talked about this situation.

                DataSetHelper dsh = new DataSetHelper();

                DataTable distinctValuesTable = dsh.SelectDistinct("distinctChildValues", dataRelation.ChildTable, columnName);

                if (distinctValuesTable.Rows.Count > 0)
                {
                    childRowsCollection = dataRelation.ChildTable.Rows.GetEnumerator(); // select everything
                }
                else
                {
                    throw new ApplicationException("No child rows for relation name [" + relationName + "] parent row index [" +
                                                   parentRowIndex + "]");
                }
            }

            // finally check for matching value of the column within all the child rows.

            object firstCellValue       = null;
            bool   firstCellValueWasSet = false;

            DataRow childRow;

            while (childRowsCollection.MoveNext())
            {
                childRow = (DataRow)childRowsCollection.Current;

                if (!firstCellValueWasSet)
                {
                    if (((isNull(childRow[columnName])) && (!ignoreNullCells)) ||
                        (!isNull(childRow[columnName])))
                    {
                        firstCellValue       = childRow[columnName];
                        firstCellValueWasSet = true;
                    }
                }
                else
                {
                    if (isNull(childRow[columnName]))
                    {
                        if (!ignoreNullCells)
                        {
                            if (!isNull(firstCellValue))
                            {
                                haveSameValue = false;
                                break;
                            }
                        }
                    }
                    else
                    {
                        if (!firstCellValue.Equals(childRow[columnName]))
                        {
                            haveSameValue = false;
                            break;
                        }
                    }
                }
            }

            return(haveSameValue);
        }
예제 #2
0
        /// <summary>
        /// Answers whether the data in the column named columnName in the child table all have the same value.
        /// </summary>
        /// <param name="ds">The Dataset</param>
        /// <param name="relationName">The index of the parent row which is being considered for this check.</param>
        /// <param name="parentRowIndex">The name of the relation between the parent and child table.  </param>
        /// <param name="columnName">The DataColumn to look for</param>
        /// <param name="ignoreNullCells">Should we ignore NULL cells</param>
        /// <returns></returns>
        public static bool columnInChildRowsHaveSameValue(DataSet ds, string relationName, int parentRowIndex,
         string columnName, bool ignoreNullCells)
        {
            bool haveSameValue = true;

             DataRelation dataRelation = ds.Relations[relationName];

             // get the child rows which correspond to the parent row

             DataRow[] childRowsArray = dataRelation.ParentTable.Rows[parentRowIndex].GetChildRows(relationName);

             IEnumerator childRowsCollection = childRowsArray.GetEnumerator();

             if (childRowsArray.Length < 1)
             {
            // special case
            // (from bug 267)
            // it appears that if one tries to group by one or more columns and all child rows happen to have DBNull in the corresponding
            // columns that GetChildRows will not find any matching child rows (when it seems that it should have returned all rows)
            // Under these circumstances we'll try to do a select distinct on the grouping columns and, if we get exactly one data item
            // back, we'll set the childRowsArray equal to all of the rows in the child table.
            // a better solution would be to somehow involve the GetChildRows call directly but I didn't find anything in my
            // web searching which talked about this situation.

            DataSetHelper dsh = new DataSetHelper();

            DataTable distinctValuesTable = dsh.SelectDistinct("distinctChildValues", dataRelation.ChildTable, columnName);

            if (distinctValuesTable.Rows.Count > 0)
            {
               childRowsCollection = dataRelation.ChildTable.Rows.GetEnumerator();  // select everything
            }
            else
            {
               throw new ApplicationException("No child rows for relation name [" + relationName + "] parent row index [" +
                  parentRowIndex + "]");
            }
             }

             // finally check for matching value of the column within all the child rows.

             object firstCellValue = null;
             bool firstCellValueWasSet = false;

             DataRow childRow;

             while (childRowsCollection.MoveNext())
             {
            childRow = (DataRow) childRowsCollection.Current;

            if (!firstCellValueWasSet)
            {
               if (		( (isNull(childRow[columnName])) && (!ignoreNullCells) )
                  ||	(!isNull(childRow[columnName])))
               {
                  firstCellValue = childRow[columnName];
                  firstCellValueWasSet = true;
               }
            }
            else
            {
               if (isNull(childRow[columnName]))
               {
                  if (!ignoreNullCells)
                  {
                     if (!isNull(firstCellValue))
                     {
                        haveSameValue = false;
                        break;
                     }
                  }
               }
               else
               {
                  if (!firstCellValue.Equals(childRow[columnName]))
                  {
                     haveSameValue = false;
                     break;
                  }
               }
            }
             }

             return haveSameValue;
        }