Question

DataTable.Select（）函数返回错误的行，并使用这样的过滤器...

“booleanColumn1 AND booleanColumn2 AND GuidColumn1 ='00000000-0000-0000-0000-000000000000'）”

对此格式进行几乎任何更改都会修复它（参见示例）。在dataView上使用相同的过滤器可以正常工作。我很想把它改成

“booleanColumn1 = 1 AND booleanColumn2 = 1 AND GuidColumn1 ='00000000-0000-0000-0000-000000000000'）”

并声明它是固定的（文档没有提到“A”或“A = 1”是否是布尔列的正确语法）。但是责任可以很容易地放在Guid专栏上。在我重新访问数百个地方之前，我们在代码库中使用DataTable.Select（），我希望看到是否有人知道实际发生了什么。

DataTable dt = new DataTable("dt");
dt.Columns.AddRange(new DataColumn[]
{
  new DataColumn("ID", typeof(Guid)),
  new DataColumn("A", typeof(bool)),
  new DataColumn("B", typeof(bool))
});

dt.Rows.Add(Guid.Empty, false, true);

// this incorrectly returns a row
Debug.WriteLine(dt.Select("B AND A AND ID = '00000000-0000-0000-0000-000000000000'").Length);

// yet it's fine for a DataView (correctly returns 0 rows)
DataView dv = new DataView(dt);
dv.RowFilter = "B AND A AND ID = '00000000-0000-0000-0000-000000000000'";
Debug.WriteLine(dv.Count);

// these correctly return 0 rows
Debug.WriteLine(dt.Select("B AND A").Length);
Debug.WriteLine(dt.Select("B AND A AND CONVERT(ID, 'System.String') = '00000000-0000-0000-0000-000000000000'").Length);
Debug.WriteLine(dt.Select("A AND B AND ID = '00000000-0000-0000-0000-000000000000'").Length);
Debug.WriteLine(dt.Select("B = 1 AND A AND ID = '00000000-0000-0000-0000-000000000000'").Length);
Debug.WriteLine(dt.Select("ID = '00000000-0000-0000-0000-000000000000' AND B AND A").Length);
Debug.WriteLine(dt.Select("B AND (A AND ID = '00000000-0000-0000-0000-000000000000')").Length);

// still wrong
Debug.WriteLine(dt.Select("B AND A AND ID = '00000000-0000-0000-0000-000000000000'").Length);

Answer 1

这绝对是一个错误，它看起来已经存在了很长时间。我发现this knowledgebase article描述了.Net framework 1.1中完全相同的错误。

似乎完全忽略了第二个条件，因为我发现以下变体也会返回一行：

dt.Select("B AND false AND ID = '00000000-0000-0000-0000-000000000000'")
dt.Select("B AND 0 AND ID = '00000000-0000-0000-0000-000000000000'")

然而，这正确地返回0行：

dt.Select("B AND A AND A AND ID = '00000000-0000-0000-0000-000000000000'")

Answer 2

不是答案。

我修改了测试，使其更容易使用，发现更多错误：

A AND B AND ID ='00000000-0000-0000-0000-000000000000'

B AND A AND（ID ='0000000-0000-0000-0000-000000000000'）

对我来说这看起来像个错误。您可能希望将其带到Microsoft Connnect。

using System;
using System.Data;
using System.Diagnostics;

class Program
{
    static void Main(string[] args)
    {
        DataTable dt = new DataTable("dt")
        {
            Columns =
            {
              new DataColumn("ID", typeof(Guid)),
              new DataColumn("A", typeof(bool)),
              new DataColumn("B", typeof(bool)),
            }
        };

        dt.Rows.Add(Guid.Empty, false, false);
        dt.Rows.Add(Guid.Empty, false, true);
        dt.Rows.Add(Guid.Empty, true, false);
        dt.Rows.Add(Guid.Empty, true, true);

        Console.BackgroundColor = ConsoleColor.Black;
        Console.Clear();
        Console.ForegroundColor = ConsoleColor.Green;
        foreach (DataRow row in dt.Rows)
            Console.WriteLine("ID = {0}, A = {1}, B = {2}", row["ID"], row["A"], row["B"]);
        Console.WriteLine();

        // this incorrectly returns a row
        Test(dt, "B AND A AND ID = '00000000-0000-0000-0000-000000000000'");

        // these correctly return 0 rows
        Test(dt, "B AND A");
        Test(dt, "B AND A AND CONVERT(ID, 'System.String') = '00000000-0000-0000-0000-000000000000'");
        Test(dt, "A AND B AND ID = '00000000-0000-0000-0000-000000000000'");
        Test(dt, "B = 1 AND A AND ID = '00000000-0000-0000-0000-000000000000'");
        Test(dt, "ID = '00000000-0000-0000-0000-000000000000' AND B AND A");
        Test(dt, "B AND (A AND ID = '00000000-0000-0000-0000-000000000000')");
        Test(dt, "(B AND A AND ID = '00000000-0000-0000-0000-000000000000')");

        // still wrong
        Test(dt, "B AND A AND ID = '00000000-0000-0000-0000-000000000000'");

        // also incorrect for both A = True and B = True
        Test(dt, "B AND A AND (ID = '0000000-0000-0000-0000-000000000000')");

        if (Debugger.IsAttached)
        {
            Console.ForegroundColor = ConsoleColor.Gray;
            Console.WriteLine();
            Console.WriteLine("Press any key to continue . . . ");
            Console.ReadKey();
        }

        Console.ResetColor();
        Console.Clear();
    }

    public static void Test(DataTable dt, string filter)
    {
        Console.ForegroundColor = ConsoleColor.White;
        Console.WriteLine(filter);
        Console.ForegroundColor = ConsoleColor.Yellow;
        Console.WriteLine("    DT = {0}, DV = {1}",
            dt.Select(filter).Length,
            new DataView { Table = dt, RowFilter = filter }.Count);
    }
}

为什么DataTable.Select（）返回错误的行？

2 个答案: