通过表名获取表结构

工作中为减少对数据库的写入次数，才用SqlBulkCopy对数据进行插入。需要获取表的结构。

获取表结构的代码如下：

 public static DataTable getTableSchema(string tableName)
        {
            DataTable dt = new DataTable();

            string sql = "SELECT syscolumns.name,systypes.name as datatype,syscolumns.isnullable,syscolumns.length FROM syscolumns, systypes WHERE syscolumns.xusertype = systypes.xusertype AND syscolumns.id = object_id('" + tableName + "')";
            SqlCommand cmd = new SqlCommand(sql,sqlConn);
            sqlConn.Open();
            SqlDataReader reader = cmd.ExecuteReader();
            while (reader.Read())
            {
                try
                {
                    dt.Columns.Add(new DataColumn(reader["name"].ToString(), SqlType2CsharpType(reader["datatype"].ToString())));
                    Console.WriteLine(reader["isnullable"].ToString());
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                    Console.WriteLine(ex.StackTrace);
                }
            }
            sqlConn.Close();
            return dt;
        }
        public static Type SqlType2CsharpType(string sqlType)
        {
            switch (sqlType)
            {
                case "bigint":
                    return typeof(Int64);
                case "binary":
                    return typeof(Object);
                case "bit":
                    return typeof(Boolean);
                case "char":
                    return typeof(String);
                case "datetime":
                    return typeof(DateTime);
                case "decimal":
                    return typeof(Decimal);
                case "float":
                    return typeof(Double);
                case "image":
                    return typeof(Object);
                case "int":
                    return typeof(int);
                case "money":
                    return typeof(Decimal);
                case "nchar":
                    return typeof(String);
                case "ntext":
                    return typeof(String);
                case "nvarchar":
                    return typeof(String);
                case "real":
                    return typeof(Single);
                case "smalldatetime":
                    return typeof(DateTime);
                case "smallint":
                    return typeof(Int16);
                case "smallmoney":
                    return typeof(Decimal);
                case "text":
                    return typeof(String);
                case "timestamp":
                    return typeof(Object);
                case "tinyint":
                    return typeof(Byte);
                case "VarBinary":
                    return typeof(Object);
                case "varchar":
                    return typeof(String);
                case "Variant":
                    return typeof(Object);
                case "xml":
                    return typeof(Object);
                default:
                    return null;
            }
        }

在使用SqlBulkCopy插入数据时，如果有自增长的列，在映射时去掉就好。