using System; using System.Collections.Generic; using System.Data; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ConsoleApplication2 { internal class Program { private static void Main(string[] args) { DataTable dt = n
操作Datatable group by 查询 //获取统计图形数据 var dicleft = new Dictionary<string, DataTable>(); ].AsEnumerable() group t by new { mname = t.Field<string>("COL_MATERIAL_NAME") } into m select new { MaterialName = m.Key.mname, value = m.ToList
public void CreateTable() { //创建表 DataTable dt = new DataTable(); //1.添加列 dt.Columns.Add("Name", typeof(string)); //数据类型为 文本 //2.通过列架构添加列 DataColumn age = new DataColumn("Age", typeof(Int32)); //数据类型为 整形 DataColumn Time = new DataColum
对datatable 里面的数据按某一特定的栏位进行分组并且按照某一规则 var query = from t in rate.AsEnumerable() group t by new { t1 = t.Field<string>("Kind") } into m select new {Kind = m.Key.t1 }; if (query.ToList().Count > 0) { query.ToList().ForEach(q => { //根据
你用SqlDataAdapter填充DataTable的时候不要用Fill方法而应该用FillSchema方法: using (SqlConnection conn = new SqlConnection("连接字符串")) { SqlCommand cmd = new SqlCommand("select * from Users", conn); conn.Open(); SqlDataAdapter sda = new SqlDataAdapter(cmd);
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; namespace dataTable自增列 { class DataTableID { /// <summary> /// 为dt表添加一个自增的ID字段 /// </summary> /// <param name="dt">用户传进来的表
之前sql用的少 竟然不知道这个小技巧 1 将要查询的列 添加到group by后面(会影响查询结果) 2 使用聚合函数如 max select a.accounttitlecode, max(b.currency),max(a.isqty) from bfacctitleaccrlat2019 a, (select case then T.crcy else 'maincurrency' end currency, T.Accounttitlecode, T.Ledger from bfacc