/// <summary> 
/// 将SQLServer数据类型转换为.Net类型
/// </summary> 
/// <param name="sqlTypeString">SQLServer数据类型</param> 
/// <returns></returns> 
public static string SqlTypeName2DotNetType(string sqlTypeString)
{
    string[] SqlTypeNames = new string[] { "int", "varchar","bit" ,"datetime","decimal","float","image","money",
"ntext","nvarchar","smalldatetime","smallint","text","bigint","binary","char","nchar","numeric",
"real","smallmoney", "sql_variant","timestamp","tinyint","uniqueidentifier","varbinary"};

    string[] DotNetTypes = new string[] {"int?", "string","bool" ,"DateTime?","Decimal","Double","Byte[]","Single",
"string","string","DateTime","Int16","string","Int64","Byte[]","string","string","Decimal",
"Single","Single", "Object","Byte[]","Byte","Guid","Byte[]"};

    int i = Array.IndexOf(SqlTypeNames, sqlTypeString.ToLower());

    return DotNetTypes[i];
}