// Copyright (c) 2004-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as published by
// the Free Software Foundation
//
// There are special exceptions to the terms and conditions of the GPL 
// as it is applied to this software. View the full text of the 
// exception in file EXCEPTIONS in the directory of this software 
// distribution.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 

using System;
using System.Data;
using System.Data.Common;
using System.Collections;
using MySql.Data.Types;
using System.Data.SqlTypes;
using System.Collections.Generic;
using System.Globalization;
using MySql.Data.MySqlClient.Properties;

namespace MySql.Data.MySqlClient
{
	/// <include file='docs/MySqlDataReader.xml' path='docs/ClassSummary/*'/>
	public sealed class MySqlDataReader : DbDataReader, IDataReader, IDataRecord
	{
		// The DataReader should always be open when returned to the user.
		private bool isOpen = true;

		private CommandBehavior commandBehavior;
		private MySqlCommand command;
		internal long affectedRows;
		internal Driver driver;
		private PreparableStatement statement;
        private ResultSet resultSet;

		/* 
		 * Keep track of the connection in order to implement the
		 * CommandBehavior.CloseConnection flag. A null reference means
		 * normal behavior (do not automatically close).
		 */
		private MySqlConnection connection;

		/*
		 * Because the user should not be able to directly create a 
		 * DataReader object, the constructors are
		 * marked as internal.
		 */
		internal MySqlDataReader(MySqlCommand cmd, PreparableStatement statement, CommandBehavior behavior)
		{
			this.command = cmd;
			connection = (MySqlConnection)command.Connection;
			commandBehavior = behavior;
			driver = connection.driver;
			affectedRows = -1;
			this.statement = statement;
		}

		#region Properties

        internal PreparableStatement Statement
        {
            get { return statement; }
        }

        internal MySqlCommand Command
        {
            get { return command; }
        }

        internal ResultSet ResultSet
        {
            get { return resultSet; }
        }

		/// <summary>
		/// Gets a value indicating the depth of nesting for the current row.  This method is not 
		/// supported currently and always returns 0.
		/// </summary>
		public override int Depth
		{
			get { return 0; }
		}

		/// <summary>
		/// Gets the number of columns in the current row.
		/// </summary>
		public override int FieldCount
		{
			get { return resultSet == null ? 0 : resultSet.Size; }
		}

		/// <summary>
		/// Gets a value indicating whether the MySqlDataReader contains one or more rows.
		/// </summary>
		public override bool HasRows
		{
			get { return resultSet == null ? false : resultSet.HasRows; }
		}

		/// <summary>
		/// Gets a value indicating whether the data reader is closed.
		/// </summary>
		public override bool IsClosed
		{
			get { return !isOpen; }
		}

		/// <summary>
		/// Gets the number of rows changed, inserted, or deleted by execution of the SQL statement.
		/// </summary>
		public override int RecordsAffected
		{
			// RecordsAffected returns the number of rows affected in batch
			// statments from insert/delete/update statments.  This property
			// is not completely accurate until .Close() has been called.
			get { return (int)affectedRows; }
		}

		/// <summary>
		/// Overloaded. Gets the value of a column in its native format.
		/// In C#, this property is the indexer for the MySqlDataReader class.
		/// </summary>
		public override object this[int i]
		{
			get { return GetValue(i); }
		}

		/// <summary>
		/// Gets the value of a column in its native format.
		///	[C#] In C#, this property is the indexer for the MySqlDataReader class.
		/// </summary>
		public override object this[String name]
		{
			// Look up the ordinal and return 
			// the value at that position.
			get { return this[GetOrdinal(name)]; }
		}

		#endregion

		/// <summary>
		/// Closes the MySqlDataReader object.
		/// </summary>
		public override void Close()
		{
			if (!isOpen) return;

			bool shouldCloseConnection = (commandBehavior & CommandBehavior.CloseConnection) != 0;
			commandBehavior = CommandBehavior.Default;

            // clear all remaining resultsets
            try
            {
              while (NextResult()) { }
            }
            catch (MySqlException ex)
            {
                if (ex.Number != 1317)
                    throw;
            }

            connection.Reader = null;
            // we now give the command a chance to terminate.  In the case of
			// stored procedures it needs to update out and inout parameters
			command.Close(this);

			if (shouldCloseConnection)
				connection.Close();

			command = null;
			connection = null;
            isOpen = false;
		}

		#region TypeSafe Accessors

		/// <summary>
		/// Gets the value of the specified column as a Boolean.
		/// </summary>
		/// <param name="name"></param>
		/// <returns></returns>
		public bool GetBoolean(string name)
		{
			return GetBoolean(GetOrdinal(name));
		}

		/// <summary>
		/// Gets the value of the specified column as a Boolean.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override bool GetBoolean(int i)
		{
			return Convert.ToBoolean(GetValue(i));
		}

		/// <summary>
		/// Gets the value of the specified column as a byte.
		/// </summary>
		/// <param name="name"></param>
		/// <returns></returns>
		public byte GetByte(string name)
		{
			return GetByte(GetOrdinal(name));
		}

		/// <summary>
		/// Gets the value of the specified column as a byte.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override byte GetByte(int i)
		{
			IMySqlValue v = GetFieldValue(i, false);
			if (v is MySqlUByte)
				return ((MySqlUByte)v).Value;
			else
				return (byte)((MySqlByte)v).Value;
		}

        /// <summary>
        /// Gets the value of the specified column as a sbyte.
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public sbyte GetSByte(string name)
        {
            return GetSByte(GetOrdinal(name));
        }

        /// <summary>
        /// Gets the value of the specified column as a sbyte.
        /// </summary>
        /// <param name="i"></param>
        /// <returns></returns>
        public sbyte GetSByte(int i)
        {
            IMySqlValue v = GetFieldValue(i, false);
            if (v is MySqlByte)
                return ((MySqlByte)v).Value;
            else
                return (sbyte)((MySqlByte)v).Value;
        }

		/// <summary>
		/// Reads a stream of bytes from the specified column offset into the buffer an array starting at the given buffer offset.
		/// </summary>
		/// <param name="i">The zero-based column ordinal. </param>
		/// <param name="fieldOffset">The index within the field from which to begin the read operation. </param>
		/// <param name="buffer">The buffer into which to read the stream of bytes. </param>
		/// <param name="bufferoffset">The index for buffer to begin the read operation. </param>
		/// <param name="length">The maximum length to copy into the buffer. </param>
		/// <returns>The actual number of bytes read.</returns>
		/// <include file='docs/MySqlDataReader.xml' path='MyDocs/MyMembers[@name="GetBytes"]/*'/>
		public override long GetBytes(int i, long fieldOffset, byte[] buffer, int bufferoffset, int length)
		{
			if (i >= FieldCount)
				throw new IndexOutOfRangeException();

			IMySqlValue val = GetFieldValue(i, false);

			if (!(val is MySqlBinary) && !(val is MySqlGuid))
				throw new MySqlException("GetBytes can only be called on binary or guid columns");

            byte[] bytes = null;
            if (val is MySqlBinary)
                bytes = ((MySqlBinary)val).Value;
            else
                bytes = ((MySqlGuid)val).Bytes;

			if (buffer == null)
                return bytes.Length;

			if (bufferoffset >= buffer.Length || bufferoffset < 0)
				throw new IndexOutOfRangeException("Buffer index must be a valid index in buffer");
			if (buffer.Length < (bufferoffset + length))
				throw new ArgumentException("Buffer is not large enough to hold the requested data");
			if (fieldOffset < 0 ||
				((ulong)fieldOffset >= (ulong)bytes.Length && (ulong)bytes.Length > 0))
				throw new IndexOutOfRangeException("Data index must be a valid index in the field");

			// adjust the length so we don't run off the end
			if ((ulong)bytes.Length < (ulong)(fieldOffset + length))
			{
				length = (int)((ulong)bytes.Length - (ulong)fieldOffset);
			}

			Buffer.BlockCopy(bytes, (int)fieldOffset, buffer, (int)bufferoffset, (int)length);

			return length;
		}

        private object ChangeType(IMySqlValue value, int fieldIndex, Type newType)
        {
#if !CF
            resultSet.Fields[fieldIndex].AddTypeConversion(newType);
#endif
            return Convert.ChangeType(value.Value, newType, CultureInfo.InvariantCulture);
        }

		/// <summary>
		/// Gets the value of the specified column as a single character.
		/// </summary>
		/// <param name="name"></param>
		/// <returns></returns>
		public char GetChar(string name)
		{
			return GetChar(GetOrdinal(name));
		}

		/// <summary>
		/// Gets the value of the specified column as a single character.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override char GetChar(int i)
		{
			string s = GetString(i);
			return s[0];
		}

		/// <summary>
		/// Reads a stream of characters from the specified column offset into the buffer as an array starting at the given buffer offset.
		/// </summary>
		/// <param name="i"></param>
		/// <param name="fieldoffset"></param>
		/// <param name="buffer"></param>
		/// <param name="bufferoffset"></param>
		/// <param name="length"></param>
		/// <returns></returns>
		public override long GetChars(int i, long fieldoffset, char[] buffer, int bufferoffset, int length)
		{
			if (i >= FieldCount)
				throw new IndexOutOfRangeException();

			string valAsString = GetString(i);

			if (buffer == null) return valAsString.Length;

			if (bufferoffset >= buffer.Length || bufferoffset < 0)
				throw new IndexOutOfRangeException("Buffer index must be a valid index in buffer");
			if (buffer.Length < (bufferoffset + length))
				throw new ArgumentException("Buffer is not large enough to hold the requested data");
			if (fieldoffset < 0 || fieldoffset >= valAsString.Length)
				throw new IndexOutOfRangeException("Field offset must be a valid index in the field");

			if (valAsString.Length < length)
				length = valAsString.Length;
			valAsString.CopyTo((int)fieldoffset, buffer, bufferoffset, length);
			return length;
		}

		/// <summary>
		/// Gets the name of the source data type.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override String GetDataTypeName(int i)
		{
			if (!isOpen) throw new Exception("No current query in data reader");
			if (i >= FieldCount) throw new IndexOutOfRangeException();

			// return the name of the type used on the backend
            IMySqlValue v = resultSet.Values[i];
            return v.MySqlTypeName;
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetMySqlDateTime/*'/>
		public MySqlDateTime GetMySqlDateTime(string column)
		{
			return GetMySqlDateTime(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetMySqlDateTime/*'/>
		public MySqlDateTime GetMySqlDateTime(int column)
		{
			return (MySqlDateTime)GetFieldValue(column, true);
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetDateTimeS/*'/>
		public DateTime GetDateTime(string column)
		{
			return GetDateTime(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetDateTime/*'/>
		public override DateTime GetDateTime(int i)
		{
			IMySqlValue val = GetFieldValue(i, true);
			MySqlDateTime dt;

            if (val is MySqlDateTime)
                dt = (MySqlDateTime)val;
            else
			{
                // we need to do this because functions like date_add return string
                string s = GetString(i);
				dt = MySqlDateTime.Parse(s);
			}

			if (connection.Settings.ConvertZeroDateTime && !dt.IsValidDateTime)
				return DateTime.MinValue;
			else
				return dt.GetDateTime();
		}

        public MySqlDecimal GetMySqlDecimal(string column)
        {
            return GetMySqlDecimal(GetOrdinal(column));
        }

        public MySqlDecimal GetMySqlDecimal(int i)
        {
			return (MySqlDecimal)GetFieldValue(i, false);
        }

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetDecimalS/*'/>
		public Decimal GetDecimal(string column)
		{
			return GetDecimal(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetDecimal/*'/>
		public override Decimal GetDecimal(int i)
		{
			IMySqlValue v = GetFieldValue(i, true);
			if (v is MySqlDecimal)
				return ((MySqlDecimal)v).Value;
			return Convert.ToDecimal(v.Value);
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetDoubleS/*'/>
		public double GetDouble(string column)
		{
			return GetDouble(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetDouble/*'/>
		public override double GetDouble(int i)
		{
			IMySqlValue v = GetFieldValue(i, true);
			if (v is MySqlDouble)
				return ((MySqlDouble)v).Value;
			return Convert.ToDouble(v.Value);
		}

        public Type GetFieldType(string column)
        {
            return GetFieldType(GetOrdinal(column));
        }

        /// <summary>
		/// Gets the Type that is the data type of the object.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override Type GetFieldType(int i)
		{
			if (!isOpen) throw new Exception("No current query in data reader");
			if (i >= FieldCount) throw new IndexOutOfRangeException();

            // we have to use the values array directly because we can't go through
            // GetValue
            IMySqlValue v = resultSet.Values[i];
			if (v is MySqlDateTime)
			{
				if (!connection.Settings.AllowZeroDateTime)
					return typeof(DateTime);
				return typeof(MySqlDateTime);
			}
			return v.SystemType;
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetFloatS/*'/>
		public float GetFloat(string column)
		{
			return GetFloat(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetFloat/*'/>
		public override float GetFloat(int i)
		{
			IMySqlValue v = GetFieldValue(i, true);
			if (v is MySqlSingle)
				return ((MySqlSingle)v).Value;
			return Convert.ToSingle(v.Value);
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetGuidS/*'/>
		public Guid GetGuid(string column)
		{
			return GetGuid(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetGuid/*'/>
		public override Guid GetGuid(int i)
		{
            object v = GetValue(i);
            if (v is Guid)
                return (Guid)v;
            if (v is string)
                return new Guid(v as string);
            if (v is byte[])
            {
                byte[] bytes = (byte[])v;
                if (bytes.Length == 16)
                    return new Guid(bytes);
            }
            throw new MySqlException(Resources.ValueNotSupportedForGuid);
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetInt16S/*'/>
		public Int16 GetInt16(string column)
		{
			return GetInt16(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetInt16/*'/>
		public override Int16 GetInt16(int i)
		{
			IMySqlValue v = GetFieldValue(i, true);
			if (v is MySqlInt16)
				return ((MySqlInt16)v).Value;

            return (short)ChangeType(v, i, typeof(short));
		}

        /// <include file='docs/MySqlDataReader.xml' path='docs/GetInt32S/*'/>
        public Int32 GetInt32(string column)
		{
			return GetInt32(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetInt32/*'/>
		public override Int32 GetInt32(int i)
		{
			IMySqlValue v = GetFieldValue(i, true);
			if (v is MySqlInt32)
				return ((MySqlInt32)v).Value;

            return (Int32)ChangeType(v, i, typeof(Int32));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetInt64S/*'/>
		public Int64 GetInt64(string column)
		{
			return GetInt64(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetInt64/*'/>
		public override Int64 GetInt64(int i)
		{
			IMySqlValue v = GetFieldValue(i, true);
			if (v is MySqlInt64)
				return ((MySqlInt64)v).Value;

            return (Int64)ChangeType(v, i, typeof(Int64));
		}

		/// <summary>
		/// Gets the name of the specified column.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override String GetName(int i)
		{
            if (!isOpen) throw new Exception("No current query in data reader");
            if (i >= FieldCount) throw new IndexOutOfRangeException();

            return resultSet.Fields[i].ColumnName;
		}

		/// <summary>
		/// Gets the column ordinal, given the name of the column.
		/// </summary>
		/// <param name="name"></param>
		/// <returns></returns>
		public override int GetOrdinal(string name)
		{
			if (!isOpen || resultSet == null)
				throw new Exception("No current query in data reader");

            return resultSet.GetOrdinal(name);
		}

		/// <summary>
		/// Returns a DataTable that describes the column metadata of the MySqlDataReader.
		/// </summary>
		/// <returns></returns>
		public override DataTable GetSchemaTable()
		{
			// Only Results from SQL SELECT Queries 
			// get a DataTable for schema of the result
			// otherwise, DataTable is null reference
			if (FieldCount == 0) return null;

			DataTable dataTableSchema = new DataTable("SchemaTable");

			dataTableSchema.Columns.Add("ColumnName", typeof(string));
			dataTableSchema.Columns.Add("ColumnOrdinal", typeof(int));
			dataTableSchema.Columns.Add("ColumnSize", typeof(int));
			dataTableSchema.Columns.Add("NumericPrecision", typeof(int));
			dataTableSchema.Columns.Add("NumericScale", typeof(int));
			dataTableSchema.Columns.Add("IsUnique", typeof(bool));
			dataTableSchema.Columns.Add("IsKey", typeof(bool));
			DataColumn dc = dataTableSchema.Columns["IsKey"];
			dc.AllowDBNull = true; // IsKey can have a DBNull
			dataTableSchema.Columns.Add("BaseCatalogName", typeof(string));
			dataTableSchema.Columns.Add("BaseColumnName", typeof(string));
			dataTableSchema.Columns.Add("BaseSchemaName", typeof(string));
			dataTableSchema.Columns.Add("BaseTableName", typeof(string));
			dataTableSchema.Columns.Add("DataType", typeof(Type));
			dataTableSchema.Columns.Add("AllowDBNull", typeof(bool));
			dataTableSchema.Columns.Add("ProviderType", typeof(int));
			dataTableSchema.Columns.Add("IsAliased", typeof(bool));
			dataTableSchema.Columns.Add("IsExpression", typeof(bool));
			dataTableSchema.Columns.Add("IsIdentity", typeof(bool));
			dataTableSchema.Columns.Add("IsAutoIncrement", typeof(bool));
			dataTableSchema.Columns.Add("IsRowVersion", typeof(bool));
			dataTableSchema.Columns.Add("IsHidden", typeof(bool));
			dataTableSchema.Columns.Add("IsLong", typeof(bool));
			dataTableSchema.Columns.Add("IsReadOnly", typeof(bool));

			int ord = 1;
			for (int i = 0; i < FieldCount; i++)
			{
				MySqlField f = resultSet.Fields[i];
				DataRow r = dataTableSchema.NewRow();
				r["ColumnName"] = f.ColumnName;
				r["ColumnOrdinal"] = ord++;
				r["ColumnSize"] = f.IsTextField ? f.ColumnLength / f.MaxLength : f.ColumnLength;
				int prec = f.Precision;
				int pscale = f.Scale;
				if (prec != -1)
					r["NumericPrecision"] = (short)prec;
				if (pscale != -1)
					r["NumericScale"] = (short)pscale;
				r["DataType"] = GetFieldType(i);
				r["ProviderType"] = (int)f.Type;
				r["IsLong"] = f.IsBlob && f.ColumnLength > 255;
				r["AllowDBNull"] = f.AllowsNull;
				r["IsReadOnly"] = false;
				r["IsRowVersion"] = false;
				r["IsUnique"] = f.IsUnique;
				r["IsKey"] = f.IsPrimaryKey;
				r["IsAutoIncrement"] = f.IsAutoIncrement;
				r["BaseSchemaName"] = f.DatabaseName;
				r["BaseCatalogName"] = null;
				r["BaseTableName"] = f.RealTableName;
				r["BaseColumnName"] = f.OriginalColumnName;

				dataTableSchema.Rows.Add(r);
			}

			return dataTableSchema;
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetStringS/*'/>
		public string GetString(string column)
		{
			return GetString(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetString/*'/>
		public override String GetString(int i)
		{
			IMySqlValue val = GetFieldValue(i, true);

			if (val is MySqlBinary)
			{
				byte[] v = ((MySqlBinary)val).Value;
				return resultSet.Fields[i].Encoding.GetString(v, 0, v.Length);
			}

			return val.Value.ToString();
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetTimeSpan/*'/>
		public TimeSpan GetTimeSpan(string column)
		{
			return GetTimeSpan(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetTimeSpan/*'/>
		public TimeSpan GetTimeSpan(int column)
		{
			IMySqlValue val = GetFieldValue(column, true);

			MySqlTimeSpan ts = (MySqlTimeSpan)val;
			return ts.Value;
		}

		/// <summary>
		/// Gets the value of the specified column in its native format.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override object GetValue(int i)
		{
			if (!isOpen) throw new Exception("No current query in data reader");
			if (i >= FieldCount) throw new IndexOutOfRangeException();

			IMySqlValue val = GetFieldValue(i, false);
			if (val.IsNull)
				return DBNull.Value;

			// if the column is a date/time, then we return a MySqlDateTime
			// so .ToString() will print '0000-00-00' correctly
			if (val is MySqlDateTime)
			{
				MySqlDateTime dt = (MySqlDateTime)val;
				if (!dt.IsValidDateTime && connection.Settings.ConvertZeroDateTime)
					return DateTime.MinValue;
				else if (connection.Settings.AllowZeroDateTime)
					return val;
				else
					return dt.GetDateTime();
			}

			return val.Value;
		}

		/// <summary>
		/// Gets all attribute columns in the collection for the current row.
		/// </summary>
		/// <param name="values"></param>
		/// <returns></returns>
		public override int GetValues(object[] values)
		{
			int numCols = Math.Min(values.Length, FieldCount);
			for (int i = 0; i < numCols; i++)
				values[i] = GetValue(i);

			return numCols;
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetUInt16/*'/>
		public UInt16 GetUInt16(string column)
		{
			return GetUInt16(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetUInt16/*'/>
		public UInt16 GetUInt16(int column)
		{
			IMySqlValue v = GetFieldValue(column, true);
			if (v is MySqlUInt16)
				return ((MySqlUInt16)v).Value;

            return (UInt16)ChangeType(v, column, typeof(UInt16));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetUInt32/*'/>
		public UInt32 GetUInt32(string column)
		{
			return GetUInt32(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetUInt32/*'/>
		public UInt32 GetUInt32(int column)
		{
			IMySqlValue v = GetFieldValue(column, true);
			if (v is MySqlUInt32)
				return ((MySqlUInt32)v).Value;
            return (uint)ChangeType(v, column, typeof(UInt32));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetUInt64/*'/>
		public UInt64 GetUInt64(string column)
		{
			return GetUInt64(GetOrdinal(column));
		}

		/// <include file='docs/MySqlDataReader.xml' path='docs/GetUInt64/*'/>
		public UInt64 GetUInt64(int column)
		{
			IMySqlValue v = GetFieldValue(column, true);
			if (v is MySqlUInt64)
				return ((MySqlUInt64)v).Value;

            return (UInt64)ChangeType(v, column, typeof(UInt64));
		}


		#endregion

		IDataReader IDataRecord.GetData(int i)
		{
			return base.GetData(i);
		}

		/// <summary>
		/// Gets a value indicating whether the column contains non-existent or missing values.
		/// </summary>
		/// <param name="i"></param>
		/// <returns></returns>
		public override bool IsDBNull(int i)
		{
			return DBNull.Value == GetValue(i);
		}

		/// <summary>
		/// Advances the data reader to the next result, when reading the results of batch SQL statements.
		/// </summary>
		/// <returns></returns>
		public override bool NextResult()
		{
			if (!isOpen)
                throw new MySqlException(Resources.NextResultIsClosed);

            // this will clear out any unread data
            if (resultSet != null)
                resultSet.Close();

            // single result means we only return a single resultset.  If we have already
            // returned one, then we return false;
            if (resultSet != null && (commandBehavior & CommandBehavior.SingleResult) != 0)
                return false;

            // next load up the next resultset if any
            try
            {
                do
                {
                    resultSet = null;
                    resultSet = driver.NextResult(Statement.StatementId);
                    if (resultSet == null) return false;
                    if (resultSet.IsOutputParameters) return false;

                    if (resultSet.Size == 0)
                    {
                        Command.lastInsertedId = resultSet.InsertedId;
                        if (affectedRows == -1)
                            affectedRows = resultSet.AffectedRows;
                        else
                            affectedRows += resultSet.AffectedRows;
                    }
                } while (resultSet.Size == 0);

				return true;
			}
            catch (MySqlException ex)
            {
				if (ex.IsFatal)
					connection.Abort();
                if (ex.Number == 0)
                    throw new MySqlException(Resources.FatalErrorReadingResult, ex);
                throw;
            }
		}

		/// <summary>
		/// Advances the MySqlDataReader to the next record.
		/// </summary>
		/// <returns></returns>
		public override bool Read()
		{
			if (!isOpen)
				throw new MySqlException("Invalid attempt to Read when reader is closed.");
            if (resultSet == null)
                return false;

            try
            {
                return resultSet.NextRow(commandBehavior);
            }
            catch (TimeoutException tex)
            {
                connection.HandleTimeout(tex);
                return false; // unreached
            }
            catch (MySqlException ex)
            {
                if (ex.IsFatal)
                    connection.Abort();

                // if we get a query interrupted then our resultset is done
                if (ex.Number == 1317)
                {
                    return false;
                }

                throw new MySqlException(Resources.FatalErrorDuringRead, ex);
            }
		}


		private IMySqlValue GetFieldValue(int index, bool checkNull)
		{
			if (index < 0 || index >= FieldCount)
				throw new ArgumentException(Resources.InvalidColumnOrdinal);

            IMySqlValue v = resultSet[index];

			if (checkNull && v.IsNull)
				throw new SqlNullValueException();

			return v;
		}

		#region IEnumerator

		/// <summary>
		/// Returns an <see cref="IEnumerator"/> that iterates through the <see cref="MySqlDataReader"/>. 
		/// </summary>
		/// <returns></returns>
		public override IEnumerator GetEnumerator()
		{
            return new DbEnumerator(this, (commandBehavior & CommandBehavior.CloseConnection) != 0);
        }

		#endregion
	}
}