1

我有一个数据集，其中包含单个 FeeID 的学生费用结构，如下所述： 

        FeeID   Amount    FeeItem             Type
      *---------------------------------------------*
        10      7500      Admission Fee        T
        10      900       Annual Fee           T
        10      150       Application Fee      T
        10      850       Boy's Uniform        T
        10      50        Computer Fee         R

例如，我有另一个包含以下数据的数据集：

        FeeID   Amount    FeeItem             Type
      *---------------------------------------------*
        9       8500      Admission Fee        T
        9       950       Annual Fee           T
        9       150       Application Fee      T
        9       850       Boy's Uniform        T
        9       50        Computer Fee         R
        11      7500      Admission Fee        T
        11      900       Annual Fee           T
        11      150       Application Fee      T
        11      850       Boy's Uniform        T
        11      50        Computer Fee         R

我想检查由最后三列组成的集合是否属于另一个数据集，该数据集包含所有费用结构的数据，其中费用 ID 可能会有所不同。实际我想检索具有相同费用结构的匹配费用 ID。

在上面的示例中，如果我在第二个中搜索第一个，它将返回True并且匹配的 FeeID 将是11。

4

3 回答 3

2

你可以使用这个技巧

Dataset ds1
DataSet ds2
DataSet dest;
dest.Merge(ds1);
dest.AcceptChanges();
dest.Merge(ds2);
diff = destination.GetChanges()

并检查 diff 是否为空

于 2012-09-04T14:12:14.640 回答
1

编辑：我对下面的代码做了一些改进。以下DataTable.IndexOf(otherTable)扩展方法检查一个表是否是另一个表的子集。

您可以传递要在比较中忽略的列名。列的顺序无关紧要，但顺序DataRows（子集必须具有相同的行顺序）。

DataRows当没有找到相等的子集或主表（this在扩展中）中相等子集开始的第一个索引时，它返回 -1 。

public static class DataTableExtensions
{
    public static int IndexOf(this DataTable tblMain, DataTable tblSub, params String[] ignoreColumns)
    {
        if (tblMain == null)
            throw new ArgumentNullException("tblMain");
        if (tblSub.Rows.Count == 0)
            throw new ArgumentException("tblSub must not be empty", "tblSub");

        if (tblSub.Rows.Count > tblMain.Rows.Count)
            return -1;

        IEnumerable<String> relevantColumnNames = tblSub.Columns.Cast<DataColumn>()
            .Select(c => c.ColumnName)
            .Except(ignoreColumns)
            .ToArray();

        foreach (String colName in relevantColumnNames)
            if (!tblMain.Columns.Contains(colName))
                return -1;

        for (int mainRowIndex = 0; tblMain.Rows.Count - mainRowIndex >= tblSub.Rows.Count; mainRowIndex++)
        {
            // check if current window is equal to tblSub
            bool allRowsAreEqual = true;
            for (int windowIndex = mainRowIndex; windowIndex < tblSub.Rows.Count + mainRowIndex; windowIndex++)
            {
                DataRow currentMain = tblMain.Rows[windowIndex];
                DataRow currentSub = tblSub.Rows[windowIndex - mainRowIndex];
                bool allFieldsAreEqual = relevantColumnNames.All(colName =>
                    Object.Equals(currentMain[colName], currentSub[colName]));
                if (!allFieldsAreEqual)
                {
                    allRowsAreEqual = false;
                    break; // continue with next window in main-table
                }
            }
            if (allRowsAreEqual)
                return mainRowIndex;
        }
        // no equal window found in main-table
        return -1;
    }
}

您的样本数据：

var TblSub = new DataTable();
var TblMain = new DataTable();
TblSub.Columns.Add("FeeID", typeof(int));
TblSub.Columns.Add("Amount", typeof(int));
TblSub.Columns.Add("FeeItem", typeof(string));
TblSub.Columns.Add("Type", typeof(char));
TblMain.Columns.Add("FeeID", typeof(int));
TblMain.Columns.Add("Amount", typeof(int));
TblMain.Columns.Add("FeeItem", typeof(string));
TblMain.Columns.Add("Type", typeof(char));

TblSub.Rows.Add(10, 7500, "Admission Free", 'T');
TblSub.Rows.Add(10, 900, "Annual Fee", 'T');
TblSub.Rows.Add(10, 150, "Application Free", 'T');
TblSub.Rows.Add(10, 850, "Boy's Uniform", 'T');
TblSub.Rows.Add(10, 50, "Computer Free", 'R');

TblMain.Rows.Add(9, 8500, "Admission Free", 'T');
TblMain.Rows.Add(9, 950, "Annual Fee", 'T');
TblMain.Rows.Add(9, 150, "Application Free", 'T');
TblMain.Rows.Add(9, 850, "Boy's Uniform", 'T');
TblMain.Rows.Add(9, 50, "Computer Free", 'R');
TblMain.Rows.Add(10, 7500, "Admission Free", 'T');
TblMain.Rows.Add(11, 900, "Annual Fee", 'T');
TblMain.Rows.Add(11, 150, "Application Free", 'T');
TblMain.Rows.Add(11, 850, "Boy's Uniform", 'T');
TblMain.Rows.Add(11, 50, "Computer Free", 'R');

你可以这样使用它：

int firstIndex = TblMain.IndexOf(TblSub, "FeeID");
if (firstIndex == -1)
    Console.Write("Second table does not contain first table");
else
    Console.Write("Second table does contain first table at row-index " + firstIndex);

输出是：

第二个表确实包含行索引 5 处的第一个表

旧方法：

您可以使用以下方法检查两个 DataTables 是否相等。

您需要添加using System.Linq. Enumerable.SequenceEqual如果您不能使用 Linq，请使用循环。

static bool TablesEqual(DataTable table1, DataTable table2, params int[] skipColumns)
{
    if (table1.Rows.Count != table2.Rows.Count)
        return false;

    for (int i = 0; i < table1.Rows.Count; i++)
    {
        var array1 = table1.Rows[i].ItemArray
            .Where((obj, index) => !skipColumns.Contains(index));
        var array2 = table2.Rows[i].ItemArray
            .Where((obj, index) => !skipColumns.Contains(index)); ;
        if (!array1.SequenceEqual(array2))
        {
            return false;
        }
    }
    return true;
}

您只需传递要忽略的列的索引，例如：

bool allEqual = TablesEqual(t1, t2); // all equal
bool equalIgnore0 = TablesEqual(t1, t2, 0); // ignore first column
bool equalIgnore0and2 = TablesEqual(t1, t2, 0, 2); // ignore first and third column
于 2012-09-04T14:28:43.000 回答
0

最后我能够解决这个问题。以下是我的功能。我正在使用Tim Schmelter提供的函数TablesEqual。该函数将返回一个有效的FeeID，它是一个正整数，如果没有找到匹配项，则返回 -1。

private int MatchFeeID(DataTable Dt)
{
  DataTable mainDt = bl.GetDataSet("Select * From FeeMaster"); //assume this is a function that will return all the fee structures from database.

  var fids = (from row in mainDt.AsEnumerable().Distinct()
            group row by row.Field<string>("fid") into rowGroup
            select new
            {
              fid = rowGroup.Key
            });

  foreach (var fid in fids)
  {
    string id = fid.fid;

    DataTable t1 = new DataTable();
    DataTable t2 = new DataTable();

    DataRow[] dr1 = mainDt.Select(String.Format("fid = '{0}'", id));

    t1 = dr1.CopyToDataTable();
    t2 = Dt;

    bool res = TablesEqual(t1, t2, 0, 1);
    if (res) return Convert.ToInt32(id);
  }

  return -1;
}
于 2012-09-04T19:46:24.050 回答