I’m afraid you can’t easily do an in-place sort of a DataTable like it sounds like you want to do. What you can do is create a new DataTable from a DataView that you create from your original DataTable. Apply whatever sorts and/or filters you want on the DataView and then create a new DataTable … Read more
The button should be an ajax button which sets the currently iterated entity in the bean, and then updates the dialog’s content, and finally shows it. The dialog should just reference that entity in the bean and update the list and table on save. It’s very important that dialog is placed outside the main form … Read more
You cannot change the DataType after the Datatable is filled with data. However, you can clone the Data table, change the column type and load data from previous data table to the cloned table as shown below. DataTable dtCloned = dt.Clone(); dtCloned.Columns[0].DataType = typeof(Int32); foreach (DataRow row in dt.Rows) { dtCloned.ImportRow(row); }
If you are allowed to use LINQ, take a look at the following example. It creates two DataTables with integer columns, fills them with some records, join them using LINQ query and outputs them to Console. DataTable dt1 = new DataTable(); dt1.Columns.Add(“CustID”, typeof(int)); dt1.Columns.Add(“ColX”, typeof(int)); dt1.Columns.Add(“ColY”, typeof(int)); DataTable dt2 = new DataTable(); dt2.Columns.Add(“CustID”, typeof(int)); dt2.Columns.Add(“ColZ”, … Read more
Look at this one: Convert List/IEnumerable to DataTable/DataView In my code I changed it into a extension method: public static DataTable ToDataTable<T>(this List<T> items) { var tb = new DataTable(typeof(T).Name); PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance); foreach(var prop in props) { tb.Columns.Add(prop.Name, prop.PropertyType); } foreach (var item in items) { var values = new object[props.Length]; … Read more
If you’re using .NET 3.5, you can use DataTableExtensions.AsEnumerable (an extension method) and then if you really need a List<DataRow> instead of just IEnumerable<DataRow> you can call Enumerable.ToList: IEnumerable<DataRow> sequence = dt.AsEnumerable(); or using System.Linq; … List<DataRow> list = dt.AsEnumerable().ToList();
JSTL tags are evaluated during building of the view, not during rendering of the view. You can visualize it as follows: Whenever a view tree get created for the first time, all JSTL tags are executed and the result is a view with only JSF components. Whenever a view tree get rendered, all JSF components … Read more
I would recommend ClosedXML – You can turn a DataTable into an Excel worksheet with some very readable code: XLWorkbook wb = new XLWorkbook(); DataTable dt = GetDataTableOrWhatever(); wb.Worksheets.Add(dt,”WorksheetName”); The developer is responsive and helpful. The project is actively developed, and the documentation is superb.
This code snippet from Convert Datatable to JSON String in C#, VB.NET might help you. It uses System.Web.Script.Serialization.JavaScriptSerializer to serialize the contents to JSON format: public string ConvertDataTabletoString() { DataTable dt = new DataTable(); using (SqlConnection con = new SqlConnection(“Data Source=SureshDasari;Initial Catalog=master;Integrated Security=true”)) { using (SqlCommand cmd = new SqlCommand(“select title=City,lat=latitude,lng=longitude,description from LocationDetails”, con)) { … Read more
There is an easier method than the other answers here, which require first deserializing into a c# class, and then turning it into a datatable. It is possible to go directly to a datatable, with JSON.NET and code like this: DataTable dt = (DataTable)JsonConvert.DeserializeObject(json, (typeof(DataTable)));