System.Data.SQLite

      /// <summary>
      /// Enable mapping of unsupported transaction isolation levels to the
      /// closest supported transaction isolation level.
      /// </summary>
      MapIsolationLevels = 0x1000000,

      /// <summary>
      /// When returning column values, attempt to map textual values
      /// onto fully conforming values of
      /// <see cref="TypeAffinity.Null" />,
      /// <see cref="TypeAffinity.Int64" />,
      /// <see cref="TypeAffinity.Double" />,
      /// or <see cref="TypeAffinity.DateTime" />.
      /// </summary>
      MapTextToAffinity = 0x2000000,

      /// <summary>
      /// When binding parameter values or returning column values, always
      /// treat them as though they were plain text (i.e. no numeric,
      /// date/time, or other conversions should be attempted).
      /// </summary>
      BindAndGetAllAsText = BindAllAsText | GetAllAsText,

            typeof(DbType), value, true);

        if (!(enumValue is DbType))
            return FallbackDefaultDbType;

        return (DbType)enumValue;
    }

    /// <summary>
    /// Determines if the specified textual value appears to be a
    /// <see cref="DBNull" /> value.
    /// </summary>
    /// <param name="text">
    /// The textual value to inspect.
    /// </param>
    /// <returns>
    /// Non-zero if the text looks like a <see cref="DBNull" /> value,
    /// zero otherwise.
    /// </returns>
    internal static bool LooksLikeNull(
        string text
        )
    {
        return (text == null);
    }

    /// <summary>
    /// Determines if the specified textual value appears to be an
    /// <see cref="Int64" /> value.
    /// </summary>
    /// <param name="text">
    /// The textual value to inspect.
    /// </param>
    /// <returns>
    /// Non-zero if the text looks like an <see cref="Int64" /> value,
    /// zero otherwise.
    /// </returns>
    internal static bool LooksLikeInt64(
        string text
        )
    {
        long longValue;

        if (!long.TryParse(text, out longValue))
            return false;

        return String.Equals(
            longValue.ToString(CultureInfo.InvariantCulture), text,
            StringComparison.Ordinal);
    }

    /// <summary>
    /// Determines if the specified textual value appears to be a
    /// <see cref="Double" /> value.
    /// </summary>
    /// <param name="text">
    /// The textual value to inspect.
    /// </param>
    /// <returns>
    /// Non-zero if the text looks like a <see cref="Double" /> value,
    /// zero otherwise.
    /// </returns>
    internal static bool LooksLikeDouble(
        string text
        )
    {
        double doubleValue;

        if (!double.TryParse(text, out doubleValue))
            return false;

        return String.Equals(
            doubleValue.ToString(CultureInfo.InvariantCulture), text,
            StringComparison.Ordinal);
    }

    /// <summary>
    /// Determines if the specified textual value appears to be a
    /// <see cref="DateTime" /> value.
    /// </summary>
    /// <param name="convert">
    /// The <see cref="SQLiteConvert" /> object instance configured with
    /// the chosen <see cref="DateTime" /> format.
    /// </param>
    /// <param name="text">
    /// The textual value to inspect.
    /// </param>
    /// <returns>
    /// Non-zero if the text looks like a <see cref="DateTime" /> in the
    /// configured format, zero otherwise.
    /// </returns>
    internal static bool LooksLikeDateTime(
        SQLiteConvert convert,
        string text
        )
    {
        if (convert == null)
            return false;

        try
        {
            DateTime dateTimeValue = convert.ToDateTime(text);

            if (String.Equals(
                    convert.ToString(dateTimeValue),
                    text, StringComparison.Ordinal))
            {
                return true;
            }
        }
        catch
        {
            // do nothing.
        }

        return false;
    }

    /// <summary>
    /// For a given type name, return a closest-match .NET type
    /// </summary>
    /// <param name="connection">The connection context for custom type mappings, if any.</param>
    /// <param name="name">The name of the type to match</param>
    /// <param name="flags">The flags associated with the parent connection object.</param>

    /// The DbType of the column, or DbType.Object if it cannot be determined
    /// </summary>
    internal DbType Type;
    /// <summary>
    /// The affinity of a column, used for expressions or when Type is DbType.Object
    /// </summary>
    internal TypeAffinity Affinity;

    ///////////////////////////////////////////////////////////////////////////

    /// <summary>
    /// Constructs a default instance of this type.
    /// </summary>
    public SQLiteType()
    {
      // do nothing.
    }

    ///////////////////////////////////////////////////////////////////////////

    /// <summary>
    /// Constructs an instance of this type with the specified field values.
    /// </summary>
    /// <param name="affinity">
    /// The type affinity to use for the new instance.
    /// </param>
    /// <param name="type">
    /// The database type to use for the new instance.
    /// </param>
    public SQLiteType(
      TypeAffinity affinity,
      DbType type
      )
      : this()
    {
      this.Affinity = affinity;
      this.Type = type;
    }
  }

  /////////////////////////////////////////////////////////////////////////////

  internal sealed class SQLiteDbTypeMap
      : Dictionary<string, SQLiteDbTypeMapping>
  {

    /// <param name="i">The index of the column to type-check</param>
    /// <param name="typ">The type we want to get out of the column</param>
    private TypeAffinity VerifyType(int i, DbType typ)
    {
      CheckClosed();
      CheckValidRow();

      TypeAffinity affinity = GetSQLiteType(SQLiteCommand.GetFlags(_command), i).Affinity;

      switch (affinity)
      {
        case TypeAffinity.Int64:
          if (typ == DbType.Int16) return affinity;
          if (typ == DbType.Int32) return affinity;
          if (typ == DbType.Int64) return affinity;

    public override string GetDataTypeName(int i)
    {
      CheckDisposed();

      if (i >= VisibleFieldCount && _keyInfo != null)
        return _keyInfo.GetDataTypeName(i - VisibleFieldCount);

      SQLiteType typ = GetSQLiteType(SQLiteCommand.GetFlags(_command), i);
      if (typ.Type == DbType.Object) return SQLiteConvert.SQLiteTypeToType(typ).Name;
      return _activeStatement._sql.ColumnType(_activeStatement, i, out typ.Affinity);
    }

    /// <summary>
    /// Retrieve the column as a date/time value
    /// </summary>

    public override Type GetFieldType(int i)
    {
      CheckDisposed();

      if (i >= VisibleFieldCount && _keyInfo != null)
        return _keyInfo.GetFieldType(i - VisibleFieldCount);

      return SQLiteConvert.SQLiteTypeToType(GetSQLiteType(SQLiteCommand.GetFlags(_command), i));
    }

    /// <summary>
    /// Returns a column as a float value
    /// </summary>
    /// <param name="i">The index of the column to retrieve</param>
    /// <returns>float</returns>

      tbl.Columns.Add(SchemaTableOptionalColumn.DefaultValue, typeof(object));
      tbl.Columns.Add("DataTypeName", typeof(string));
      tbl.Columns.Add("CollationType", typeof(string));
      tbl.BeginLoadData();

      for (int n = 0; n < _fieldCount; n++)
      {
        SQLiteType sqlType = GetSQLiteType(SQLiteCommand.GetFlags(_command), n);

        row = tbl.NewRow();

        DbType typ = sqlType.Type;

        // Default settings for the column
        row[SchemaTableColumn.ColumnName] = GetName(n);

    {
      CheckDisposed();
      CheckValidRow();

      if (i >= VisibleFieldCount && _keyInfo != null)
        return _keyInfo.GetValue(i - VisibleFieldCount);

      SQLiteConnectionFlags flags = SQLiteCommand.GetFlags(_command);
      SQLiteType typ = GetSQLiteType(flags, i);

      if (((flags & SQLiteConnectionFlags.MapTextToAffinity) == SQLiteConnectionFlags.MapTextToAffinity) &&
          (typ != null) && (typ.Affinity == TypeAffinity.Text))
      {
          typ = GetSQLiteType(
              typ, _activeStatement._sql.GetText(_activeStatement, i));
      }

      return _activeStatement._sql.GetValue(_activeStatement, flags, i, typ);

    }

    /// <summary>
    /// Retreives the values of multiple columns, up to the size of the supplied array
    /// </summary>
    /// <param name="values">The array to fill with values from the columns in the current resultset</param>
    /// <returns>The number of columns retrieved</returns>

        catch (ObjectDisposedException)
        {
            // do nothing.
        }

        return SQLiteConnectionFlags.Default;
    }

    /// <summary>
    /// Retrieves the SQLiteType for a given column and row value.
    /// </summary>
    /// <param name="oldType">
    /// The original SQLiteType structure, based only on the column.
    /// </param>
    /// <param name="text">
    /// The textual value of the column for a given row.
    /// </param>
    /// <returns>
    /// The SQLiteType structure.
    /// </returns>
    private SQLiteType GetSQLiteType(
        SQLiteType oldType,
        string text
        )
    {
        if (SQLiteConvert.LooksLikeNull(text))
            return new SQLiteType(TypeAffinity.Null, DbType.Object);

        if (SQLiteConvert.LooksLikeInt64(text))
            return new SQLiteType(TypeAffinity.Int64, DbType.Int64);

        if (SQLiteConvert.LooksLikeDouble(text))
            return new SQLiteType(TypeAffinity.Double, DbType.Double);

        if ((_activeStatement != null) &&
            SQLiteConvert.LooksLikeDateTime(_activeStatement._sql, text))
        {
            return new SQLiteType(TypeAffinity.DateTime, DbType.DateTime);
        }

        return oldType;
    }

    /// <summary>
    /// Retrieves the SQLiteType for a given column, and caches it to avoid repetetive interop calls.
    /// </summary>
    /// <param name="flags">The flags associated with the parent connection object.</param>
    /// <param name="i">The index of the column to retrieve</param>
    /// <returns>A SQLiteType structure</returns>
    private SQLiteType GetSQLiteType(SQLiteConnectionFlags flags, int i)
    {
      SQLiteType typ;

      // Initialize the field types array if not already initialized
      if (_fieldTypeArray == null)
        _fieldTypeArray = new SQLiteType[VisibleFieldCount];

      // Initialize this column's field type instance
      if (_fieldTypeArray[i] == null) _fieldTypeArray[i] = new SQLiteType();

      typ = _fieldTypeArray[i];

      // If not initialized, then fetch the declared column datatype and attempt to convert it
      // to a known DbType.
      if (typ.Affinity == TypeAffinity.Uninitialized)
        typ.Type = SQLiteConvert.TypeNameToDbType(GetConnection(this), _activeStatement._sql.ColumnType(_activeStatement, i, out typ.Affinity), flags);
      else
        typ.Affinity = _activeStatement._sql.ColumnAffinity(_activeStatement, i);

      return typ;
    }

    /// <summary>