[问题] 如何在DataSet中根据条件选出想要的记录？ [100分]。。。。谢谢

[asgard]

比如现在得到的DataSet中dataSet.Table[0]的内容为：
key1 key2 value
----------------------
1 1 1_name
1 1 1_name
1 2 2_name
1 2 2_name
2 1 abcd

如何从中选出一个rows的集合，条件为key1=1并且key2不重复，也就是:

key1 key2 value
----------------------
1 1 1_name
1 2 2_name

（最后结果按key2排序）
谢谢！

[hedonister]

Datatable dt = dataSet.Table[0];
DataView dv = new DataView(dt);

dv.RowFilter = "key1 = 1";
dv.RowStateFilter = DataViewRowState.ModifiedCurrent;

[hedonister]

再加句
dv.Sort = "key2 DESC";

[jialiang]

dataSet.Table[0].Select("key1=1","key2")
然后通过遍例自己处理重复的数据

[机器人]

strExpr = "id > 5"
' Sort descending by CompanyName column.
strSort = "name DESC"
' Use the Select method to find all rows matching the filter.
Dim foundRows As DataRow() = _
customerTable.Select( strExpr, strSort, DataViewRowState.Added )

[机器人]

这个代码你试试看:
private static DataTable GetDataTableByFilter( DataTable sourceDataTable )
{

DataTable filteredTable = new DataTable( "Filtered" );
// Add columns
filteredTable.Columns.Add( "Key1", typeof(string) );
filteredTable.Columns.Add( "Key2", typeof(string) );
filteredTable.Columns.Add( "Value", typeof(string) );

// Set PrimaryKey
filteredTable.Columns[ "Key2" ].Unique = true;
filteredTable.PrimaryKey = new DataColumn[] { filteredTable.Columns["Key2"] };

string strExpr;
string strSort;

strExpr = "Key1 = 1";
// Sort descending by one column named.
strSort = "Key2 DESC";
// Use the Select method to find all rows matching the filter.
filteredDataTable.Rows =
sourceDataTable.Select( strExpr, strSort, DataViewRowState.Added );
return filteredDataTable;
}

[机器人]

Sorry,重复数据还得通过循环来判断。如果像上述那样的话会抛出异常的。

[manonroad]

用dataview，
然后dv.RowFilter = "Key1 = 1";
dv.Sort = "Key2";

[marvelstack]

Ke2 不重复,你需要遍历过滤排序后的数据.拷贝一份不重复的数据到另一个DataTable,