C# 使用列名从数据视图中查找值
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Find value from the dataview using column name
提问by Muhammad Rizwan Shahid
I am trying to find value from dataview using column name. My dataset shows value but my if condition returns false. I am working in asp.net using c#.
我正在尝试使用列名从数据视图中查找值。我的数据集显示值，但我的 if 条件返回 false。我正在使用 c# 在 asp.net 中工作。
I have tried with different code. I am trying to get value like this
我尝试过不同的代码。我试图获得这样的价值
dv[0].DataView.Table.Columns[0].ToString().Contains("52")
//RETURN FALSE
OR
dv[0].Equals("52")
// //RETURN FALSE
OR
或者
dv[0].Find("52")
// //RETURN FALSE
Following is my dataset
以下是我的数据集
回答by Steven Jennings
int rowIndex = dv.Find("52");
if (rowIndex == -1) {
Console.WriteLine("No match found.");
}
else {
Console.WriteLine("{0}, {1}",
dv(rowIndex)("GBA_Nbr_GBAccount").ToString(),
dv(rowIndex)("GBA_Nam_GBAccount").ToString());
}
I think that may be the solution to your problem, or at the very least point you in the right direction.
我认为这可能是您问题的解决方案，或者至少为您指明了正确的方向。
回答by BhargavaKatta
If "GBA_Nbr_GBAccount" column is a string type, it may contains spaces. You should trim text before comparing. Try this
如果“GBA_Nbr_GBAccount”列是字符串类型，则可能包含空格。您应该在比较之前修剪文本。尝试这个
dv[0]["GBA_Nbr_GBAccount"].ToString().Trim().Equals("52");
回答by Daniel J.G.
You could use Linqto query the datatable or the dataview. For example, assuming your column is of type string:
您可以Linq用来查询数据表或数据视图。例如，假设您的列是字符串类型：
var condition = yourDataTable.AsEnumerable()
.Any(r => r.Field<string>("GBA_Nbr_GBAccount") == "52");
var condition = yourDataView.Cast<DataRowView>()
.Any(rv => rv.Row.Field<string>("GBA_Nbr_GBAccount") == "52");
If the column was an integer, just change the Field<string>to Field<int>and compare against an integer, not a string
如果该列是整数，只需更改Field<string>toField<int>并与整数进行比较，而不是字符串
var condition = yourDataTable.AsEnumerable()
.Any(r => r.Field<int>("GBA_Nbr_GBAccount") == 52);
var condition = yourDataView.Cast<DataRowView>()
.Any(rv => rv.Row.Field<int>("GBA_Nbr_GBAccount") == 52);
Example application using string column:
使用字符串列的示例应用程序：
static void Main(string[] args)
{
DataSet dataset = new DataSet();
dataset.Tables.Add(new DataTable("table1"));
dataset.Tables[0].Columns.Add(new DataColumn("Value", typeof(string)));
dataset.Tables[0].Rows.Add("10");
dataset.Tables[0].Rows.Add("52");
DataTable table = dataset.Tables[0];
DataView view = table.DefaultView;
var condition1 = table.AsEnumerable().Any(r => r.Field<string>("Value") == "52");
var condition2 = view.Cast<DataRowView>().Any(rv => rv.Row.Field<string>("Value") == "52");
Console.WriteLine(String.Format("Result querying datatable: '{0}'. Result using dataview:'{1}'", condition1, condition2));
Console.ReadLine();
}
If you are really using a string for the column, check for white spaces and apply a trim if needed.
如果您真的为列使用字符串，请检查空格并根据需要应用修剪。
回答by Ben
One way to check for the existence of a specific column in a dataview would be like the following:
检查数据视图中特定列是否存在的一种方法如下所示：
if (dv.Table.Columns["Name"] != null)
{
//Name column exists. Add Logic here
}
回答by Sam
Use the DataViewManager object instead it has a DataSet property associated with it and the dataset has all the normal dataset features. So, you can traverse the dataset.tables[index] object...
使用 DataViewManager 对象，而不是它具有与之关联的 DataSet 属性，并且数据集具有所有正常的数据集功能。所以，你可以遍历 dataset.tables[index] 对象...
Hope it helps
希望能帮助到你
Example: dv.DataViewManager.DataSet.Tables[0].Rows[0][1]
示例：dv.DataViewManager.DataSet.Tables[0].Rows[0][1]
Thanks, Sam
谢谢，山姆
