The following does it in a single line: dataTable.Rows.OfType<DataRow>() .Select(dr => dr.Field<MyType>(columnName)).ToList(); [Edit: Add a reference to System.Data.DataSetExtensions to your project if this does not compile]
The Merge method takes the values from the second table and merges them in with the first table, so the first will now hold the values from both. If you want to preserve both of the original tables, you could copy the original first, then merge: dtAll = dtOne.Copy(); dtAll.Merge(dtTwo);
Yes, the DataTable.Select method supports boolean operators in the same way that you would use them in a “real” SQL statement: DataRow[] results = table.Select(“A = ‘foo’ AND B = ‘bar’ AND C = ‘baz'”); See DataColumn.Expression in MSDN for the syntax supported by DataTable’s Select method.
int index = dt.Rows.IndexOf(row); But you’re probably better off using a for loop instead of foreach.
The DataRow has also an indexer: Object cellValue = dt.Rows[i][j]; But i would prefer the strongly typed Field extension method which also supports nullable types: int number = dt.Rows[i].Field<int>(j); or even more readable and less error-prone with the name of the column: double otherNumber = dt.Rows[i].Field<double>(“DoubleColumn”);
Create a User-Defined TableType in your database: CREATE TYPE [dbo].[MyTableType] AS TABLE( [Id] int NOT NULL, [Name] [nvarchar](128) NULL ) and define a parameter in your Stored Procedure: CREATE PROCEDURE [dbo].[InsertTable] @myTableType MyTableType readonly AS BEGIN insert into [dbo].Records select * from @myTableType END and send your DataTable directly to sql server: using (var command … Read more
var singleString = string.Join(“,”, _values.ToArray() );
@William You can use NewRow method of the datatable to get a blank datarow and with the schema as that of the datatable. You can populate this datarow and then add the row to the datatable using .Rows.Add(DataRow) OR .Rows.InsertAt(DataRow, Position). The following is a stub code which you can modify as per your convenience. … Read more
To calculate the sum of a column in a DataTable use the DataTable.Compute method. Example of usage from the linked MSDN article: DataTable table = dataSet.Tables[“YourTableName”]; // Declare an object variable. object sumObject; sumObject = table.Compute(“Sum(Amount)”, string.Empty); Display the result in your Total Amount Label like so: lblTotalAmount.Text = sumObject.ToString();
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)));