C# 将过滤后的数据从数据集获取到数据表
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Get filtered data from dataset to datatable
提问by palak
How can I filter data from dataset to datatable? like the code->
如何将数据从数据集过滤到数据表？喜欢代码->
DataRow[] dr = DS.Tables[0]
.Select("STAGENAME='Develop' AND DEVLAPSEDAYS IS NOT NULL");
How can I use datatable here?
我如何在这里使用数据表？
following code doesn`t reflect changes->
以下代码不反映更改->
DataTable FilteredDataD = DS.Tables[0];
if (FilteredDataD.Rows.Count > 0) {
FilteredDataD.DefaultView.RowFilter = "STAGENAME='Develop' AND DEVLAPSEDAYS IS NOT NULL";
FilteredDataD.DefaultView.ToTable();
}
Is is possible to remove a column using above filter,like "STAGENAME='Develop' AND DEVLAPSEDAYS IS NOT NULL" + FilteredDataD.column("col_name")... Suppose I have 5 columns display only 4,I can`t remove col_name from my query.Is there a way?
是否可以使用上述过滤器删除列，例如“STAGENAME='Develop' AND DEVLAPSEDAYS IS NOT NULL”+ FilteredDataD.column("col_name")...假设我有 5 列只显示 4，我无法删除col_name 来自我的查询。有办法吗？
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回复
采纳答案by James Johnson
Try using LINQ instead:
尝试使用 LINQ：
var table = DS.Tables[0].AsEnumerable().Where(
r => r.Field<string>("STAGENAME") == "Develop" && r.Field<int?>("DEVLAPSEDAYS").HasValue).AsDataView().ToTable();
EDITChanged AsDataViewto AsDataView()for syntactical accuracy.
EDITProvided .NET 2.0 compatible solution
编辑改AsDataView到AsDataView()了语法准确性。
编辑提供 .NET 2.0 兼容解决方案
DataTable table = DS.Tables[0];
if (table.Rows.Count > 0)
{
table.DefaultView.RowFilter = "STAGENAME = 'DEVELOP' AND DEVLAPSEDAYS IS NOT NULL";
table = table.DefaultView.ToTable();
}
回答by Matt
You could write an extension method (using C# 3) like follows:
您可以编写一个扩展方法（使用 C# 3），如下所示：
public static DataTable Filter(this DataTable dataTable, string selectFilter)
{
var filteredTable = dataTable.Clone();
var rows = dataTable.Select(selectFilter).ToList();
rows.ForEach(filteredTable.ImportRow);
return filteredTable;
}
Then use it like follows:
然后像下面这样使用它：
DataTable dataTable = DS.Tables[0]
.Filter("STAGENAME='Develop' AND DEVLAPSEDAYS IS NOT NULL");
Update, since you said you are using C# 2.0 (and thus extension methods and LINQ aren't an option) you could use this instead:
更新，因为您说您使用的是 C# 2.0（因此扩展方法和 LINQ 不是一个选项），您可以改用它：
public static DataTable GetFilteredTable(
DataTable sourceTable, string selectFilter)
{
var filteredTable = sourceTable.Clone();
var rows = sourceTable.Select(selectFilter);
foreach (DataRow row in rows)
{
filteredTable.ImportRow(row);
}
return filteredTable;
}
DataTable dataTable = GetFilteredTable(
DS.Tables[0], "STAGENAME='Develop' AND DEVLAPSEDAYS IS NOT NULL");
