繁花不似锦
如果允许使用LINQ，请查看以下示例。它创建两个带有整数列的DataTables，用一些记录填充它们，使用LINQ查询连接它们并将它们输出到Console。 DataTable dt1 = new DataTable(); dt1.Columns.Add("CustID", typeof(int)); dt1.Columns.Add("ColX", typeof(int)); dt1.Columns.Add("ColY", typeof(int)); DataTable dt2 = new DataTable(); dt2.Columns.Add("CustID", typeof(int)); dt2.Columns.Add("ColZ", typeof(int)); for (int i = 1; i <= 5; i++) { DataRow row = dt1.NewRow(); row["CustID"] = i; row["ColX"] = 10 + i; row["ColY"] = 20 + i; dt1.Rows.Add(row); row = dt2.NewRow(); row["CustID"] = i; row["ColZ"] = 30 + i; dt2.Rows.Add(row); } var results = from table1 in dt1.AsEnumerable() join table2 in dt2.AsEnumerable() on (int)table1["CustID"] equals (int)table2["CustID"] select new { CustID = (int)table1["CustID"], ColX = (int)table1["ColX"], ColY = (int)table1["ColY"], ColZ = (int)table2["ColZ"] }; foreach (var item in results) { Console.WriteLine(String.Format("ID = {0}, ColX = {1}, ColY = {2}, ColZ = {3}", item.CustID, item.ColX, item.ColY, item.ColZ)); } Console.ReadLine();// Output:// ID = 1, ColX = 11, ColY = 21, ColZ = 31// ID = 2, ColX = 12, ColY = 22, ColZ = 32// ID = 3, ColX = 13, ColY = 23, ColZ = 33// ID = 4, ColX = 14, ColY = 24, ColZ = 34// ID = 5, ColX = 15, ColY = 25, ColZ = 35
动漫人物
我想要一个连接表的函数，而不需要使用匿名类型选择器定义列，但很难找到任何。我最终不得不自己做。希望这将有助于将来搜索此内容的任何人：private DataTable JoinDataTables(DataTable t1, DataTable t2, params Func<DataRow, DataRow, bool>[] joinOn){
DataTable result = new DataTable();
foreach (DataColumn col in t1.Columns)
{
if (result.Columns[col.ColumnName] == null)
result.Columns.Add(col.ColumnName, col.DataType);
}
foreach (DataColumn col in t2.Columns)
{
if (result.Columns[col.ColumnName] == null)
result.Columns.Add(col.ColumnName, col.DataType);
}
foreach (DataRow row1 in t1.Rows)
{
var joinRows = t2.AsEnumerable().Where(row2 =>
{
foreach (var parameter in joinOn)
{
if (!parameter(row1, row2)) return false;
}
return true;
});
foreach (DataRow fromRow in joinRows)
{
DataRow insertRow = result.NewRow();
foreach (DataColumn col1 in t1.Columns)
{
insertRow[col1.ColumnName] = row1[col1.ColumnName];
}
foreach (DataColumn col2 in t2.Columns)
{
insertRow[col2.ColumnName] = fromRow[col2.ColumnName];
}
result.Rows.Add(insertRow);
}
}
return result;}您可以如何使用此示例：var test = JoinDataTables(transactionInfo, transactionItems,
(row1, row2) =>
row1.Field<int>("TransactionID") == row2.Field<int>("TransactionID"));一个警告：这当然没有优化，所以在获得超过20k的行数时要小心。如果您知道一个表将比另一个表大，请尝试将较小的表放在第一个，将较大的表放在第二个表中。