Need to get empty datatable in .net with database table schema

Question

What is the best way to create an Empty DataTable object with the schema of a sql server table?

Answer 1

Assuming that you can connect to the SQL database which contains the table you want to copy at the point it time you want to do this, you could use a conventional resultset to datatable conversion, using

select * from <tablename> where 1=2

as your source query.

This will return an empty result set with the structure of the source table.

Answer 2

this works:

Class BlankTableWithSourceTableSchema
    Inherits DataTable
    Public Sub New(ByVal connstr As String, ByVal sourcetable As String)
        Try
            Using connection As SqlServerCe.SqlCeConnection = New SqlServerCe.SqlCeConnection(connstr)
                Dim adapter As SqlServerCe.SqlCeDataAdapter = New SqlServerCe.SqlCeDataAdapter("SELECT * FROM " & sourcetable, connection)
                adapter.TableMappings.Add("Table", "ABlankTable")
                adapter.FillSchema(Me, SchemaType.Mapped)
            End Using
        Catch ex As Exception
        End Try
    End Sub
End Class

Answer 3

Here's what I did, which provides a blank DataTable ready to be used:

SqlConnection _sqlConnection = new SqlConnection ();
_sqlConnection.ConnectionString = @"Data Source=<SQL_Server/Instance>; Initial Catalog=<database_name>; Integrated Security=False; User ID=<user_id>;Password=<passowrd>";
_sqlConnection.Open ();
SqlCommand _sqlCommand = new SqlCommand ( "select * from DatabaseName.dbo.viewName", _sqlConnection ); 
_dataSet = new DataSet ();
_sqlDataAdapter = new SqlDataAdapter ( _sqlCommand );
_sqlDataAdapter.Fill ( _dataSet );
_schemaTable = new DataTable ();
_sqlDataAdapter.FillSchema ( _schemaTable, SchemaType.Source );
dataGridView.DataSource = _schemaTable;
_sqlConnection.Close ();

Answer 4

A statement I think is worth mentioning is SET FMTONLY:

SET FMTONLY ON;
SELECT * FROM SomeTable
SET FMTONLY OFF;

No rows are processed or sent to the client because of the request when SET FMTONLY is turned ON.

The reason this can be handy is because you can supply any query/stored procedure and return just the metadata of the resultset.