Question

我创建了一个Datatable，我试图减少行数。我能够找到一种方法来检查表中是否存在testID并合并主机名但我不确定如何删除源行。

示例dtOrginal：

testID passFail description hostname
1ab    pass     ....        alpha
1ab    pass     ....        bravo
1ab    fail     ....        charlie
1ac    pass     ....        alpha

当前结果示例：

testID passFail description hostname
1ab    pass     ....        alpha, bravo
1ab    pass     ....        bravo
1ab    fail     ....        charlie
1ac    pass     ....        alpha

我想要的是什么

testID passFail description hostname
1ab    pass     ....        alpha, bravo
1ab    fail     ....        charlie
1ac    pass     ....        alpha

这是我当前在必要时合并主机名和testID的函数

DataTable dtReducedColumns = CombineHostnames(dtOrinal).Copy();

private static DataTable CombineHostnames(DataTable dt)
    {
        for (int i = 0; i < dtOrginal.Rows.Count; i++)
        {
            bool isDupe = false;
            string a, b, c, d, e, f, g, h, k, l;

            for (int j = 0; j < dt.Rows.Count; j++)
            {
                a = dtOrginal.Rows[i][0].ToString(); //testID
                b = dt.Rows[j][0].ToString();
                c = dtOrginal.Rows[i][1].ToString(); //passFail
                d = dt.Rows[j][1].ToString();
                g = dtOrginal.Rows[i][2].ToString(); //description
                h = dt.Rows[j][2].ToString();
                if (a == b && c == d && g == h)
                {
                    e = dt.Rows[j][10].ToString();
                    f = dtOrginal.Rows[i][10].ToString(); //hostname
                    k = dtOrginalRows[i][8].ToString(); //source
                    l = dt.Rows[j][8].ToString();
                    if (!e.Contains(f))
                        dt.Rows[j][10] = e + ", " + f; //combine hostnames
                    if (!k.Contains(l))
                        dt.Rows[j][8] = k + ", " + l; //combine sources
                    isDupe = true;
                    //tried adding dt.Rows[j].Delete() here
                    //tried adding dt.Rows[j-1].Delete() here get -1 error
                    break;
                } 
               //tried adding dt.Rows[j].Delete() here
               //tried adding dt.Rows[j-1].Delete() here get -1 error
            }
            //tried adding dt.Rows[j].Delete() here
            //tried adding dt.Rows[j-1].Delete() here get -1 error

            if (!isDupe)
            {
                dt.ImportRow(dtOrginal.Rows[i]);
            }
        }
        return dt;
    }

我尝试删除行的地方会引发IndexOutOfBounds异常或返回类似于dtOrginal的表格。

供参考，以下是我使用的整个DataTable：

dtChecklistFindingsTable = new DataTable();                                  //Column Number
dtChecklistFindingsTable.Columns.Add("testID", typeof(string));              // 0
dtChecklistFindingsTable.Columns.Add("passFail", typeof(string));            // 1
dtChecklistFindingsTable.Columns.Add("description", typeof(string));         // 2
dtChecklistFindingsTable.Columns.Add("vulLevel", typeof(string));            // 3
dtChecklistFindingsTable.Columns.Add("recommendation", typeof(string));      // 4
dtChecklistFindingsTable.Columns.Add("comments", typeof(string));            // 5
dtChecklistFindingsTable.Columns.Add("title", typeof(string));               // 6
dtChecklistFindingsTable.Columns.Add("testCheck", typeof(string));           // 7
dtChecklistFindingsTable.Columns.Add("source", typeof(string));              // 8
dtChecklistFindingsTable.Columns.Add("date", typeof(string));                // 9
dtChecklistFindingsTable.Columns.Add("hostName", typeof(string));            // 10
dtChecklistFindingsTable.Columns.Add("os", typeof(string));                  // 11
dtChecklistFindingsTable.Columns.Add("ipAddr", typeof(string));              // 12
dtChecklistFindingsTable.Columns.Add("stigLevel", typeof(string));           // 13
dtChecklistFindingsTable.Columns.Add("stigSeverity", typeof(string));        // 14
dtChecklistFindingsTable.Columns.Add("sarStatus", typeof(string));           // 15
dtChecklistFindingsTable.Columns.Add("iaControl", typeof(string));           // 16

Answer 1

这是Linq-To-DataTable的一个很好的用例，尤其是Enumerable.GroupBy + String.Join：

private static DataTable CombineHostnames(DataTable dtOrginal)
{
    DataTable tblresult = dtOrginal.Clone(); // empty table, same columns
    var rowGroups = dtOrginal.AsEnumerable()
        .GroupBy(row => new
        {
            Id = row.Field<string>("testId"),
            passFail = row.Field<string>("passFail")
        });

    foreach (var group in rowGroups)
    {
        DataRow row = tblresult.Rows.Add(); // already added now
        row.SetField("testId", group.Key.Id);
        row.SetField("passFail", group.Key.passFail);
        row.SetField("description", group.First()["description"]);  // the first?
        string hostNames = String.Join(", ", group.Select(r => r.Field<string>("hostname")));
        row.SetField("hostname", hostNames);
    }
    return tblresult;
}

您可以通过简单地使用每个组中的第一个或其他逻辑，以与我已添加description相同的方式添加其他列。

DataTable组合值并删除源行

1 个答案: