如何动态地向数据集添加列 [英] How to add a column to a dataset dynamically
问题描述
使用以下代码我想动态添加一列但是我在行中收到此错误
'ds21.Columns.Add(theCol);'
错误13'System.Data.DataSet'不包含'Columns'的定义,也没有扩展方法'Columns'接受类型'System.Data'的第一个参数。可以找到DataSet'(你是否缺少using指令或汇编引用?)
我的代码:
DataSet ds21 = new DataSet(productname);
DataColumn theCol = new DataColumn(Groups,typeof(string));
ds21.Columns。添加(theCol);
da2.Fill(ds21,productname);
如何纠正此问题。
DataSet没有列; DataTables可以。
此外,即使您尝试使用DataTable,我也认为这不会起作用。您可以考虑将该列添加到用于获取数据的查询中。
DataSet是DataTables的集合吗?
我知道你可以这样做: -
DataTable dt21 = new DataTable( productname);
DataColumn theCol = new DataColumn( Groups , typeof ( string ));
dt21.Columns.Add(theCol);
da2.Fill(dt21, productname);
然后你可能会这样做: -
DataSet set = new DataSet( < span class =code-string> productmaster);
set .Tables.Add(dt21);
例如
....
'g'
< blockquote>试试吧..
DataTable ds21 = new DataTable( productname);
da2.Fill(ds21);
DataColumn theCol = new DataColumn( Groups , typeof ( string ));
ds21.Columns.Add(theCol);
With the following code I wanted to add a column dynamically but I get this error at line
'ds21.Columns.Add(theCol);'
Error 13 'System.Data.DataSet' does not contain a definition for 'Columns' and no extension method 'Columns' accepting a first argument of type 'System.Data.DataSet' could be found (are you missing a using directive or an assembly reference?)
My code:
DataSet ds21 = new DataSet("productname");
DataColumn theCol = new DataColumn("Groups", typeof(string));
ds21.Columns.Add(theCol);
da2.Fill(ds21, "productname");
How to rectify this.
DataSets don't have Columns; DataTables do.
Additionally, I don't think that will work even if you try to do it with a DataTable. You might consider adding the column to the query you are using to get the data.
Isnt a DataSet a collection of DataTables ?
I know you can do this :-
DataTable dt21 = new DataTable("productname"); DataColumn theCol = new DataColumn("Groups", typeof(string)); dt21.Columns.Add(theCol); da2.Fill(dt21, "productname");
and then you'd likely do this :-
DataSet set = new DataSet("productmaster"); set.Tables.Add(dt21);
for example
....
'g'
Try this..
DataTable ds21 = new DataTable("productname"); da2.Fill(ds21); DataColumn theCol = new DataColumn("Groups", typeof(string)); ds21.Columns.Add(theCol);
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