LINQ to DataSet需要使用System.Core.dll.System.Data.dll和System.Data.DataSetExtensions.dll,在项目中添加引用System.Data和System.Data.DataSetExtensions. 1. DataTable读取列表 DataSet ds = new DataSet(); // 省略ds的Fill代码 DataTable products = ds.Tables["Product"]; IEnume…

DataTable通过dt.AsEnumerable()方法转换可用Linq查询,反之,Linq也可以转化为DataTableDataTable newDt = query1.CopyToDataTable<DataRow>();var query1 =    from stu in dtStu.AsEnumerable()    from score in dtScore.AsEnumerable()    where stu.Field<int>("ScoreID&q…

DataTable与List相互转换 .NET后台数据处理,从数据库中的捞出的数据格式一般是List和DataTable的格式.现在将两种格式相互转换的心得记录下来以便以后查找(直接上代码). public class ConvertHelper<T> where T : new() { //将DataTable转换为List public static List<T> ConvertToList(DataTable dt) { // 定义集合 var ls = new List&…

DataTable Linq查询 1.查询DataRow IEnumerable<DataRow> q1 = from r in dt.AsEnumerable() == select r; 2.查询某个字段 var query2 = from pl in dt.AsEnumerable( ) select pl.Field<string>("Name"); 3.group by var query = from r in dt.AsEnumerable() g…

使用 FastMember: IEnumerable<SomeType> data = ... DataTable table = new DataTable(); using(var reader = ObjectReader.Create(data)) { table.Load(reader); } This uses the FastMember's meta-programming API for maximum performance. If you want to restrict…

datatable我们是经常使用到的,但是需要对数据进行分组,具体代码如下: var result = dt.AsEnumerable().GroupBy(f => new { type = f.Field<string>("type"), value = f.Field<string>("value"), site_id = f.Field<string>("site_id") }).Select(f…

实例: DataTable data = new DataTable(); data.Columns.Add("schoolid", Type.GetType("System.Int32")); data.Columns.Add("ccid", Type.GetType("System.Int32")); DataRow newRow1 = data.NewRow(); newRow1["schoolid"…

public static T GetEntity<T>(DataTable table) where T : new() { T entity = new T(); foreach (DataRow row in table.Rows) { foreach (var item in entity.GetType().GetProperties()) { if (row.Table.Columns.Contains(item.Name)) { if (DBNull.Value != row[i…

DataRow drt = null; var tlist = dt.Select("Atmbs LIKE '%" + d["Two_Code"] + "%'").AsEnumerable().GroupBy(a => a.Field<string>("STATUS_MISSIONN")).Select(e => new { STATUS_MISSIONN = e.Key, Number = e.Cou…

关于datatable datarow DataTable paraval = GetParaVal(DateCondition, strUrl, Page, RowPage, iYearMonthNow, 2); var query = from t in paraval.AsEnumerable() //datatable 和linq转换 group t by new { t1 = t.Field<string>("InsKind") } into m select n…