I've seen a few posts about this and I had to write a function to do it
so I thought I'd share.  (It uses ODBC cause that was the requirement I
had for a small job):

public class TableExport
    {
        public TableExport()
        {
            //
            // TODO: Add constructor logic here
            //
        }

        #region CSV
        public static void GenerateCSV(DataTable dt, System.IO.TextWriter
httpStream, bool WriteHeader)
        {
            if(WriteHeader)
            {
                string[] arr = new String[dt.Columns.Count];
                for(int i = 0; i<dt.Columns.Count; i++)
                {
                    arr[i] = dt.Columns[i].ColumnName;
                    arr[i] = GetWriteableValue(arr[i]);
                }

                httpStream.WriteLine(string.Join(",", arr));
            }

            for(int j = 0; j<dt.Rows.Count; j++)
            {
                string[] dataArr = new String[dt.Columns.Count];
                for(int i = 0; i<dt.Columns.Count; i++)
                {
                    object o = dt.Rows[j][i];
                    dataArr[i] = GetWriteableValue(o);
                }
                httpStream.WriteLine(string.Join(",", dataArr));
            }
        }

        public static void GenerateCSV(DataTable dt, System.IO.StreamWriter
file, bool WriteHeader)
        {
            if(WriteHeader)
            {
                string[] arr = new String[dt.Columns.Count];
                for(int i = 0; i<dt.Columns.Count; i++)
                {
                    arr[i] = dt.Columns[i].ColumnName;
                    arr[i] = GetWriteableValue(arr[i]);
                }

                file.WriteLine(string.Join(",", arr));
            }

            for(int j = 0; j<dt.Rows.Count; j++)
            {
                string[] dataArr = new String[dt.Columns.Count];
                for(int i = 0; i<dt.Columns.Count; i++)
                {
                    object o = dt.Rows[j][i];
                    dataArr[i] = GetWriteableValue(o);
                }
                file.WriteLine(string.Join(",", dataArr));
            }
        }

        public static string GetWriteableValue(object o)
        {
            if(o==null || o == Convert.DBNull)
                return "";
            else if(o.ToString().IndexOf(",")==-1)
                return o.ToString();
            else
                return "\"" + o.ToString() + "\"";

        }
        #endregion

        public static void CreateTable(string connectionString, string
tableNameToCreate, DataTable dataTable)
        {
            StringCollection _columnsToCreate = new StringCollection();
            bool _textImage = false;
            foreach(DataColumn _col in dataTable.Columns)
            {
                bool _needsText = false;
                string _colVal = MapType(_col, dataTable, out _needsText);
                if (_needsText == true)
                    _textImage = true;

                _columnsToCreate.Add(string.Format("[{0}] {1} NULL,",
_col.ColumnName, _colVal));
            }
            _columnsToCreate[_columnsToCreate.Count - 1] =
_columnsToCreate[_columnsToCreate.Count - 1].Substring(0,
_columnsToCreate[_columnsToCreate.Count - 1].Length - 1);
            GenerateCreateTableScript(connectionString, tableNameToCreate,
_columnsToCreate, _textImage);
            AddRecords(connectionString, tableNameToCreate, dataTable);
        }

        public static void AddRecords(string connectionString, string
tableToAddTo, DataTable dataTable)
        {
            using(OdbcConnection _conn = new OdbcConnection(connectionString))
            {
                _conn.Open();
                OdbcCommand _cmd = new OdbcCommand("select * from " + tableToAddTo,
_conn);
                OdbcDataAdapter _adapter = new OdbcDataAdapter(_cmd);

                DataTable _newTable = dataTable.Copy();
                _newTable.Rows.Clear();

                foreach(DataRow _row in dataTable.Rows)
                {
                    _newTable.Rows.Add(_row.ItemArray);
                }

                OdbcCommandBuilder _cmdBuilder = new OdbcCommandBuilder(_adapter);
                _adapter.Update(_newTable);
                _newTable.AcceptChanges();
            }
        }

        private static void GenerateCreateTableScript(string dsn, string
tableNameToCreate, StringCollection columnsToCreate, bool
needsTextImage)
        {
            //if exists (select * from dbo.sysobjects where id =
object_id(N'[dbo].[Andrew2]') and OBJECTPROPERTY(id, N'IsUserTable') =
1)
            //drop table [dbo].[Andrew2]
            //GO
            // CREATE TABLE [dbo].[Andrew] (
            // ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

            StringBuilder _createTable = new StringBuilder();
            _createTable.Append(string.Format("if exists (select * from
dbo.sysobjects where id = object_id(N'[dbo].[{0}]') and
OBJECTPROPERTY(id, N'IsUserTable') = 1)", tableNameToCreate) +
Environment.NewLine);
            _createTable.Append(string.Format("drop table [dbo].[{0}]",
tableNameToCreate) + Environment.NewLine);
            _createTable.Append(Environment.NewLine);
            _createTable.Append(string.Format("CREATE TABLE [dbo].[{0}] (",
tableNameToCreate));

            foreach(string _column in columnsToCreate)
            {
                _createTable.Append(_column + Environment.NewLine);
            }
            _createTable.Append(") ON [PRIMARY]");
            if (needsTextImage)
                _createTable.Append("TEXTIMAGE_ON [PRIMARY]");

            using(OdbcConnection _conn = new OdbcConnection(dsn))
            {
                _conn.Open();
                OdbcCommand _cmd = new OdbcCommand(_createTable.ToString(), _conn);
                _cmd.ExecuteNonQuery();
            }
        }

        private static string MapType(DataColumn column, DataTable dataTable,
out bool textImage)
        {
            textImage = false;
            //Boolean    Bit
            //Byte    Tinyint
            //Byte[]    Image
            //DateTime    DateTime
            //Decimal    Decimal
            //Double    Float
            //Guid    Uniqueidentifier
            //Int16    SmallInt
            //Int32    Int
            //Int64    Bigint
            //Object    SqlVariant
            //Single    Real
            //String    Text



            switch(column.DataType.FullName)
            {
                case "System.Boolean":
                    return "[bit]";
                case "System.Byte":
                    return "[tinyint]";
                case "System.Byte[]":
                    int _maxSizeBinary = 50;
                    foreach(DataRow _row in dataTable.Rows)
                    {
                        if (!(_row[column] is DBNull))
                        {
                            byte[] _val = (byte[])_row[column];
                            if (_val.Length > _maxSizeBinary)
                                _maxSizeBinary = _val.Length;
                        }
                    }
                    if (_maxSizeBinary > 7950) // Max size of varbinary is 8000,
padding 50 to be safe
                    {
                        textImage = true;
                        return "[image]";
                    }
                    else
                        return string.Format("[varbinary]({0})", _maxSizeBinary);
                case "System.DateTime":
                    return "[datetime]";
                case "System.Decimal":
                    return "[decimal]";
                case "System.Double":
                    return "[float]";
                case "System.Guid":
                    return "[uniqueidentifier]";
                case "System.Int16":
                    return "[smallint]";
                case "System.Int32":
                    return "[int]";
                case "System.Int64":
                    return "[bigint]";
                case "System.Object":
                    return "[sql_variant]";
                case "System.Single":
                    return "[real]";
                case "System.String":
                    int _maxSizeString = 50;
                    foreach(DataRow _row in dataTable.Rows)
                    {
                        if (!(_row[column] is DBNull))
                        {
                            string _val = (string)_row[column];
                            if (_val.Length > _maxSizeString)
                                _maxSizeString = _val.Length;
                        }
                    }
                    if (_maxSizeString > 3950) // Max size of nvarchar is 4000,
padding 50 to be safe
                    {
                        textImage = true;
                        return "[text] COLLATE SQL_Latin1_General_CP1_CI_AS";
                    }
                    else
                        return string.Format("[nvarchar]({0})", _maxSizeString);
                default:
                    throw new Exception("unsupported variable type found");
            }
            return null;
        }
    }

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