解决.ToPivotTable(it => it.day, it =>new{ it.name}, it => it.Sum(x => x.count))的几个问题

1 it.name 为空值时抛出异常索引超出界值异常
2 当it.name 的值中 有"T0 = T1 = T2"类似情况是会截断字符串，显示为"T0"
3 提升转化效率，现在所花时间只需要之前的1/4左右

Src/Asp.NetCore2/MySqlTest/a9_ToPivot.cs

@@ -0,0 +1,126 @@
+#region using
+using OrmTest;
+using SqlSugar;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+#endregion
+
+namespace MySqlTest
+{
+    public class _a9_ToPivot
+    {
+
+        public static void Init()
+        {
+
+            var db = DbHelper.GetNewDb();
+            db.CodeFirst.SetStringDefaultLength(200).InitTables(typeof(RowToColumn));
+            Clean();
+            InitData();
+            Test5();
+            Test6();
+        }
+        public static void InitData()
+        {
+            var db = DbHelper.GetNewDb();
+            var ls = new List<RowToColumn>();
+            // 创建 Stopwatch 对象并开始计时
+            Stopwatch stopwatch = new Stopwatch();
+            stopwatch.Start();
+
+            for (int i = 1; i <= 100 * 10000; i++)
+            {
+                ls.Add(new RowToColumn()
+                {
+                    Id = Guid.NewGuid(),
+                    Code = "A" + i % 1000,
+                    Date = new DateTime(2023, i % 11 + 1, 1),
+                    Date2 = new DateTime(2023, i % 11 + 1, i % 28 + 1, i % 24, i % 60, i % 60),
+                    Val = i % 10,
+                    T1 = i % 3 == 0 ? null : "T0",
+                    T2 = i % 3 == 1 ? null : 3
+                }); ;
+                if (i % 100000 == 0)
+                {
+                    db.Fastest<RowToColumn>().PageSize(100000).BulkCopy(ls);
+                    ls.Clear();
+                }
+            }
+
+            Task.Run(() =>
+            {
+            });
+            // 结束计时并获取经过的时间
+            stopwatch.Stop();
+            TimeSpan elapsedTime = stopwatch.Elapsed;
+
+            Console.WriteLine("T0:" + elapsedTime);
+        }
+        public static void Clean()
+        {
+            var db = DbHelper.GetNewDb();
+            db.DbMaintenance.TruncateTable<RowToColumn>();
+        }
+
+        public static void Test5()
+        {
+            var db = DbHelper.GetNewDb();
+            // 创建 Stopwatch 对象并开始计时
+            Stopwatch stopwatch = new Stopwatch();
+            stopwatch.Start();
+            var s = new DateTime(2023, 2, 1);
+            var e = new DateTime(2023, 6, 1).AddMilliseconds(-1);
+            var ls = db.Queryable<RowToColumn>()
+                .Where(x => x.Date >= s && x.Date <= e)
+                .GroupBy(x => new { x.Code, x.Date, x.Val, x.T1, x.T2 })
+                .Select(x => new { x.Code, x.Date, x.T1, x.T2, Val = SqlFunc.AggregateSum(x.Val) })//求和可以自动处理空值
+                .ToPivotTable(it => it.Code, it => new { it.Date, it.T1, it.T2 }, it => it.Any() ? it.Sum(x => x.Val) : 0);
+
+            // 结束计时并获取经过的时间
+            stopwatch.Stop();
+            TimeSpan elapsedTime = stopwatch.Elapsed;
+
+            Console.WriteLine("T5:" + elapsedTime);
+        }
+        public static void Test6()
+        {
+            var db = DbHelper.GetNewDb();
+            // 创建 Stopwatch 对象并开始计时
+            Stopwatch stopwatch = new Stopwatch();
+            stopwatch.Start();
+            var s = new DateTime(2023, 2, 1);
+            var e = new DateTime(2023, 6, 1).AddMilliseconds(-1);
+            var ls = db.Queryable<RowToColumn>()
+               .Where(x => x.Date >= s && x.Date <= e)
+               .GroupBy(x => new { x.Code, x.Date, x.Val, x.T1, x.T2 })
+               .Select(x => new { x.Code, x.Date, x.T1, x.T2, Val = SqlFunc.AggregateSum(x.Val) })//求和可以自动处理空值
+               .ToPivotList(it => it.Code, it => new { it.Date, it.T1, it.T2 }, it => it.Any() ? it.Sum(x => x.Val) : 0);
+
+            // 结束计时并获取经过的时间
+            stopwatch.Stop();
+            TimeSpan elapsedTime = stopwatch.Elapsed;
+
+            Console.WriteLine("T000:" + elapsedTime);
+        }
+    }
+
+    [SugarTable("row_2_column")]
+    public class RowToColumn
+    {
+        [SugarColumn(IsPrimaryKey = true)]
+        public Guid Id { get; set; }
+        public DateTime Date { get; set; }
+        public DateTime Date2 { get; set; }
+        public string Code { get; set; }
+        public decimal? Val { get; set; }
+        [SugarColumn(ColumnName = "t_1", IsNullable = true)]
+        public string T1 { get; set; }
+        [SugarColumn(ColumnName = "t_2", IsNullable = true)]
+        public int? T2 { get; set; }
+    }
+}

Src/Asp.NetCore2/SqlSugar/Utilities/DataTableExtensions.cs

@@ -2,13 +2,15 @@
 using System.Collections.Generic;
 using System.Data;
 using System.Dynamic;
+using System.IO;
 using System.Linq;
 using System.Linq.Expressions;
+using System.Reflection;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 
-namespace SqlSugar 
+namespace SqlSugar
 {
     internal static class DataTableExtensions
     {
@@ -19,12 +21,13 @@ namespace SqlSugar
     Func<IEnumerable<T>, TData> dataSelector)
         {
             DataTable table = new DataTable();
-            var rowName = "";
+            var rowName = new List<string>();
             if (rowSelector.Body is MemberExpression)
-                rowName = ((MemberExpression)rowSelector.Body).Member.Name;
+                rowName.Add(((MemberExpression)rowSelector.Body).Member.Name);
             else
-                rowName =string.Join(UtilConstants.ReplaceKey, ((NewExpression)rowSelector.Body).Arguments.Select(it=>it as MemberExpression).Select(it=>it.Member.Name));
-            table.Columns.Add(new DataColumn(rowName));
+                rowName.AddRange(((NewExpression)rowSelector.Body).Arguments.Select(it => it as MemberExpression).Select(it => it.Member.Name));
+
+            table.Columns.AddRange(rowName.Select(x => new DataColumn(x)).ToArray());
             var columns = source.Select(columnSelector).Distinct();
 
             foreach (var column in columns)
@@ -45,36 +48,23 @@ namespace SqlSugar
             {
                 var dataRow = table.NewRow();
                 var items = row.Values.Cast<object>().ToList();
-                items.Insert(0, row.Key);
+                // 获取匿名对象的动态类型  
+                var anonymousType = row.Key.GetType();
+
+                // 获取匿名对象的所有属性  
+                var properties = anonymousType.GetProperties();
+
+                for (var i = 0; i < rowName.Count; i++)
+                {
+                    items.Insert(i, properties[i].GetValue(row.Key, null));
+                }
                 dataRow.ItemArray = items.ToArray();
                 table.Rows.Add(dataRow);
             }
-            var firstName = table.Columns[0]?.ColumnName;
-            if (firstName.ObjToString().Contains(UtilConstants.ReplaceKey)) 
-            {
-                int i = 0;
-                foreach (var item in Regex.Split(firstName,UtilConstants.ReplaceKey))
-                {
-                    i++;
-                    table.Columns.Add(item);
-                    table.Columns[item].SetOrdinal(i);
-                }
-                foreach (DataRow row in table.Rows)
-                {
-                    var json =row[firstName];
-                    var list = json.ToString().TrimStart('{', ' ').TrimEnd('}', ' ')
-                        .Split(new[] { ", " }, StringSplitOptions.None)
-                        .Select(it => it.Split(new[] { " = " }, StringSplitOptions.None)).ToList();
-                    foreach (var item in Regex.Split(firstName, UtilConstants.ReplaceKey))
-                    {
-                        var x = list.First(it => it.First().Trim() == item.Trim());
-                        row[item] =x[1] ;
-                    }
-                }
-                table.Columns.Remove(firstName);
-            }
+
             return table;
         }
+
         public static List<dynamic> ToPivotList<T, TColumn, TRow, TData>(
                                                                         this IEnumerable<T> source,
                                                                         Func<T, TColumn> columnSelector,
@@ -82,17 +72,17 @@ namespace SqlSugar
                                                                         Func<IEnumerable<T>, TData> dataSelector)
         {
 
-            var arr = new List<object>();
+            var arr = new List<dynamic>();
             var cols = new List<string>();
-            var rowName = "";
+            var rowName = new List<string>();
             if (rowSelector.Body is MemberExpression)
-                rowName = ((MemberExpression)rowSelector.Body).Member.Name;
+                rowName.Add(((MemberExpression)rowSelector.Body).Member.Name);
             else
-                rowName = "Group_"+string.Join("_", ((NewExpression)rowSelector.Body).Arguments.Select(it => it as MemberExpression).Select(it => it.Member.Name));
+                rowName.AddRange(((NewExpression)rowSelector.Body).Arguments.Select(it => it as MemberExpression).Select(it => it.Member.Name));
+
             var columns = source.Select(columnSelector).Distinct();
 
-            cols = (new[] { rowName }).Concat(columns.Select(x => x?.ToString())).ToList();
-
+            cols = rowName.Concat(columns.Select(x => x?.ToString())).ToList();
 
             var rows = source.GroupBy(rowSelector.Compile())
                              .Select(rowGroup => new
@@ -103,17 +93,26 @@ namespace SqlSugar
                                      c => c,
                                      r => columnSelector(r),
                                      (c, columnGroup) => dataSelector(columnGroup))
-                             }).ToList();
-
+                             });
 
             foreach (var row in rows)
             {
                 var items = row.Values.Cast<object>().ToList();
-                items.Insert(0, row.Key);
+
+                // 获取匿名对象的动态类型  
+                var anonymousType = row.Key.GetType();
+
+                // 获取匿名对象的所有属性  
+                var properties = anonymousType.GetProperties();
+
+                for (var i = 0; i < rowName.Count; i++)
+                {
+                    items.Insert(i, properties[i].GetValue(row.Key, null));
+                }
                 var obj = GetAnonymousObject(cols, items);
                 arr.Add(obj);
             }
-            return arr.ToList();
+            return arr;
         }
         private static dynamic GetAnonymousObject(IEnumerable<string> columns, IEnumerable<object> values)
         {