SQL Server到.Net类型的转换

Question

我有以下地图用于转换SQL Server类型,SQLData类型和.NET类型:

/// <summary>
    /// The map of types. THis maps all the corresponding types between sql server types, .net sql types, and .net types
    /// </summary>
    public static List<SqlTypeConversionHolder> TypeList = new List<SqlTypeConversionHolder>()
    {
        new SqlTypeConversionHolder("bigint", typeof(SqlInt64),typeof(Int64)),
        new SqlTypeConversionHolder("binary", typeof(SqlBytes),typeof(Byte[])),
        new SqlTypeConversionHolder("bit", typeof(SqlBoolean),typeof(Boolean)),
        new SqlTypeConversionHolder("char", typeof(SqlChars),typeof(char)), //this one may need work
        new SqlTypeConversionHolder("cursor", null,null),
        new SqlTypeConversionHolder("date", typeof(SqlDateTime),typeof(DateTime)),
        new SqlTypeConversionHolder("datetime", typeof(SqlDateTime),typeof(DateTime)),
        new SqlTypeConversionHolder("datetime2", null,typeof(DateTime)),
        new SqlTypeConversionHolder("DATETIMEOFFSET", null,typeof(DateTimeOffset)),
        new SqlTypeConversionHolder("decimal", typeof(SqlDecimal),typeof(Decimal)),
        new SqlTypeConversionHolder("float", typeof(SqlDouble),typeof(Double)),
        //new SqlTypeConversionHolder("geography", typeof(SqlGeography),typeof(null));
        //new SqlTypeConversionHolder("geometry", typeof(SqlGeometry),typeof(null));
        //new SqlTypeConversionHolder("hierarchyid", typeof(SqlHierarchyId),typeof(null));
        new SqlTypeConversionHolder("image", null,null),
        new SqlTypeConversionHolder("int", typeof(SqlInt32),typeof(Int32)),
        new SqlTypeConversionHolder("money", typeof(SqlMoney),typeof(Decimal)),
        new SqlTypeConversionHolder("nchar", typeof(SqlChars),typeof(String)),
        new SqlTypeConversionHolder("ntext", null,null),
        new SqlTypeConversionHolder("numeric", typeof(SqlDecimal),typeof(Decimal)),
        new SqlTypeConversionHolder("nvarchar", typeof(SqlChars),typeof(String)),
        new SqlTypeConversionHolder("nvarchar(1)", typeof(SqlChars),typeof(Char)),
        new SqlTypeConversionHolder("nchar(1)", typeof(SqlChars),typeof(Char)),
        new SqlTypeConversionHolder("real", typeof(SqlSingle),typeof(Single)),
        new SqlTypeConversionHolder("rowversion", null,typeof(Byte[])),
        new SqlTypeConversionHolder("smallint", typeof(SqlInt16),typeof(Int16)),
        new SqlTypeConversionHolder("smallmoney", typeof(SqlMoney),typeof(Decimal)),
        new SqlTypeConversionHolder("sql_variant", null,typeof(Object)),
        new SqlTypeConversionHolder("table", null,null),
        new SqlTypeConversionHolder("text", typeof(SqlString),typeof(string)), //this one may need work
        new SqlTypeConversionHolder("time", null,typeof(TimeSpan)),
        new SqlTypeConversionHolder("timestamp", null,null),
        new SqlTypeConversionHolder("tinyint", typeof(SqlByte),typeof(Byte)),
        new SqlTypeConversionHolder("uniqueidentifier", typeof(SqlGuid),typeof(Guid)),
        new SqlTypeConversionHolder("varbinary", typeof(SqlBytes),typeof(Byte[])),
        new SqlTypeConversionHolder("varbinary(1)", typeof(SqlBytes),typeof(byte)),
        new SqlTypeConversionHolder("binary(1)", typeof(SqlBytes),typeof(byte)),
        new SqlTypeConversionHolder("varchar", typeof(SqlString),typeof(string)), //this one may need work
        new SqlTypeConversionHolder("xml", typeof(SqlXml),typeof(string))
    };

a的第一个参数SqlTypeConversionHolder是sql server类型的名称.第二个参数是.Net Sql类型.第三种是.net类型.

那些说This one may need work的是我不确定的.有人可以提供一些帮助,说明正确的转换是什么？在MSDN上看,似乎他们没有正确的转换类型.我觉得很难相信.必须有某种方式从SQL Server类型转到.NET类型.

Answer 1

根据 MSDN，您的所有三个（char、varchar、text）都正确。

请参阅：http ://msdn.microsoft.com/en-us/library/system.data.sqltypes.aspx