dt常用类

经常使用的一些datatable的操作，包括一些过滤去重的方法

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;

namespace TravcomRptTest.Common
{
    public abstract class Dt
    {
        #region 按条件过滤DataTable
        public static DataTable TblFilter(DataTable sourceTable, string condition)
        {
            var tempDt = sourceTable.Clone();
            var rows = sourceTable.Select(condition);
            foreach (var dr in rows)
            {
                tempDt.ImportRow(dr);
            }
            return tempDt;
        }

        public static DataTable TblFilter(DataTable sourceTable, string condition, string[] columns)
        {
            var tempDt = new DataTable();
            foreach (var t in columns)
            {
                tempDt.Columns.Add(t, typeof(String));
            }
            var rows = sourceTable.Select(condition);
            foreach (var dr in rows)
            {
                var newDr = tempDt.NewRow();
                foreach (var t in columns)
                {
                    newDr[t.Split(':')[]] = dr[t.Split(':')[]].ToString();
                }
                tempDt.Rows.Add(newDr);
            }
            return tempDt;
        }
        #endregion
        #region 按条件过滤DataTable，并排序
        public static DataTable TblFilter(DataTable sourceTable, string condition, string orderBy)
        {
            var tempDt = sourceTable.Clone();
            var rows = sourceTable.Select(condition, orderBy);
            foreach (var dr in rows)
            {
                tempDt.ImportRow(dr);
            }
            return tempDt;
        }
        #endregion
        #region 筛选不重复的sourceColumn数据，单Column
        public static DataTable TblDistinct(DataTable sourceTable, string sourceColumn)
        {
            try
            {
                var result = sourceTable.Clone();
                var ht = new Hashtable();
                foreach (var dr in sourceTable.Rows.Cast<DataRow>().Where(dr => !ht.ContainsKey(dr[sourceColumn])))
                {
                    ht.Add(dr[sourceColumn], null);
                    var newRow = result.NewRow();
                    newRow.ItemArray = dr.ItemArray;
                    result.Rows.Add(newRow);
                }
                return result;
            }
            catch (Exception)
            {
                return null;
            }
        }
        #endregion
        #region 筛选不重复的sourceColumn数据，单Column，指定数据类型
        public static DataTable TblDistinct(DataTable sourceTable, string sourceColumn, Type columnType)
        {
            var result = sourceTable.Clone();
            result.TableName = "DT";
            result.Columns[sourceColumn].DataType = columnType;
            try
            {
                var ht = new Hashtable();
                foreach (var dr in sourceTable.Rows.Cast<DataRow>().Where(dr => !ht.ContainsKey(dr[sourceColumn])))
                {
                    ht.Add(dr[sourceColumn], null);
                    var newRow = result.NewRow();
                    newRow.ItemArray = dr.ItemArray;
                    result.Rows.Add(newRow);
                }
                return result;
            }
            catch (Exception)
            {
                return null;
            }
        }
        #endregion
        #region 筛选不重复的sourceColumn数据，双Column
        public static DataTable TblDistinct(DataTable sourceTable, string key1, string key2)
        {
            try
            {
                var result = sourceTable.Clone();
                var ht = new Hashtable();
                foreach (var dr in sourceTable.Rows.Cast<DataRow>().Where(dr => !ht.ContainsKey(dr[key1] + dr[key2].ToString())))
                {
                    ht.Add(dr[key1] + dr[key2].ToString(), null);
                    var newRow = result.NewRow();
                    newRow.ItemArray = dr.ItemArray;
                    result.Rows.Add(newRow);
                }
                return result;
            }
            catch (Exception)
            {
                return null;
            }
        }
        #endregion
        #region 筛选不重复的sourceColumn数据，多Column
        public static DataTable TblDistinct(DataTable sourceTable, string[] arrKey)
        {
            try
            {
                var result = sourceTable.Clone();
                var ht = new Hashtable();
                foreach (DataRow dr in sourceTable.Rows)
                {
                    var strKey = arrKey.Aggregate(string.Empty, (current, t) => current + dr[t]);
                    if (ht.ContainsKey(strKey)) continue;
                    ht.Add(strKey, null);
                    var newRow = result.NewRow();
                    newRow.ItemArray = dr.ItemArray;
                    result.Rows.Add(newRow);
                }
                return result;
            }
            catch (Exception)
            {
                return null;
            }
        }
        #endregion
        #region 获取单一值
        public static string GetSingle(string columnName, string condition, DataTable dt)
        {
            try
            {
                return TblFilter(dt, condition).Rows[][columnName].ToString();
            }
            catch
            {
                return string.Empty;
            }
        }
        //获取单一值，为空返回默认值
        public static string GetSingle(string columnName, string condition, DataTable dt, string defaultValue)
        {
            string strReturn;
            try
            {
                strReturn = TblFilter(dt, condition).Rows[][columnName].ToString();
            }
            catch
            {
                strReturn = string.Empty;
            }
            if (strReturn.Trim() == "")
            {
                strReturn = defaultValue;
            }
            return strReturn;
        }
        #endregion
        #region 获得一个带结构的DataTable
        public static DataTable GetNewTbl(string tableName)
        {
            var dt = new DataTable();
            switch (tableName)
            {

                case "ConfigModel":
                    #region
                    dt.Columns.Add("Name", typeof(String));
                    dt.Columns.Add("id", typeof(String));
                    dt.Columns.Add("MI01", typeof(String));
                    #endregion
                    break;
            }
            return dt;
        }
        #endregion

        //public static DataTable listToTable(List<Model.Segment> segList)
        //{
        //    DataTable dt = new DataTable();
        //    dt.Columns.Add("psgqueue");
        //    dt.Columns.Add("airqueue");
        //    dt.Columns.Add("ticketno");
        //    for (int i = 0; i < segList.Count; i++)
        //    {
        //        DataRow dr = dt.NewRow();
        //        dr["psgqueue"] = segList[i].psgqueue;
        //        dr["airqueue"] = segList[i].airQueue;
        //        dr["ticketno"] = segList[i].ticketno;
        //        dt.Rows.Add(dr);
        //    }

        //    return dt;
        //}

    }
}