[c#] C# Equivalent of SQL Server DataTypes

For the following SQL Server datatypes, what would be the corresponding datatype in C#?

Exact Numerics

bigint
numeric
bit
smallint
decimal
smallmoney
int
tinyint
money

Approximate Numerics

float
real

Date and Time

date
datetimeoffset
datetime2
smalldatetime
datetime
time

Character Strings

char
varchar
text

Unicode Character Strings

nchar
nvarchar
ntext

Binary Strings

binary
varbinary
image

Other Data Types

cursor
timestamp
hierarchyid
uniqueidentifier
sql_variant
xml
table

(source: MSDN)

SQL Server and .Net Data Type mapping

public static string FromSqlType(string sqlTypeString)
{
    if (! Enum.TryParse(sqlTypeString, out Enums.SQLType typeCode))
    {
        throw new Exception("sql type not found");
    }
    switch (typeCode)
    {
        case Enums.SQLType.varbinary:
        case Enums.SQLType.binary:
        case Enums.SQLType.filestream:
        case Enums.SQLType.image:
        case Enums.SQLType.rowversion:
        case Enums.SQLType.timestamp://?
            return "byte[]";
        case Enums.SQLType.tinyint:
            return "byte";
        case Enums.SQLType.varchar:
        case Enums.SQLType.nvarchar:
        case Enums.SQLType.nchar:
        case Enums.SQLType.text:
        case Enums.SQLType.ntext:
        case Enums.SQLType.xml:
            return "string";
        case Enums.SQLType.@char:
            return "char";
        case Enums.SQLType.bigint:
            return "long";
        case Enums.SQLType.bit:
            return "bool";
        case Enums.SQLType.smalldatetime:
        case Enums.SQLType.datetime:
        case Enums.SQLType.date:
        case Enums.SQLType.datetime2:
            return "DateTime";
        case Enums.SQLType.datetimeoffset:
            return "DateTimeOffset";
        case Enums.SQLType.@decimal:
        case Enums.SQLType.money:
        case Enums.SQLType.numeric:
        case Enums.SQLType.smallmoney:
            return "decimal";
        case Enums.SQLType.@float:
            return "double";
        case Enums.SQLType.@int:
            return "int";
        case Enums.SQLType.real:
            return "Single";
        case Enums.SQLType.smallint:
            return "short";
        case Enums.SQLType.uniqueidentifier:
            return "Guid";
        case Enums.SQLType.sql_variant:
            return "object";
        case Enums.SQLType.time:
            return "TimeSpan";
        default:
            throw new Exception("none equal type");
    }
}

public enum SQLType
{
    varbinary,//(1)
    binary,//(1)
    image,
    varchar,
    @char,
    nvarchar,//(1)
    nchar,//(1)
    text,
    ntext,
    uniqueidentifier,
    rowversion,
    bit,
    tinyint,
    smallint,
    @int,
    bigint,
    smallmoney,
    money,
    numeric,
    @decimal,
    real,
    @float,
    smalldatetime,
    datetime,
    sql_variant,
    table,
    cursor,
    timestamp,
    xml,
    date,
    datetime2,
    datetimeoffset,
    filestream,
    time,
}

SQL Server and .Net Data Type mapping

SQL Server and the .NET Framework are based on different type systems. For example, the .NET Framework Decimal structure has a maximum scale of 28, whereas the SQL Server decimal and numeric data types have a maximum scale of 38. Click Here's a link! for detail

https://msdn.microsoft.com/en-us/library/cc716729(v=vs.110).aspx

public static string FromSqlType(string sqlTypeString)
{
    if (! Enum.TryParse(sqlTypeString, out Enums.SQLType typeCode))
    {
        throw new Exception("sql type not found");
    }
    switch (typeCode)
    {
        case Enums.SQLType.varbinary:
        case Enums.SQLType.binary:
        case Enums.SQLType.filestream:
        case Enums.SQLType.image:
        case Enums.SQLType.rowversion:
        case Enums.SQLType.timestamp://?
            return "byte[]";
        case Enums.SQLType.tinyint:
            return "byte";
        case Enums.SQLType.varchar:
        case Enums.SQLType.nvarchar:
        case Enums.SQLType.nchar:
        case Enums.SQLType.text:
        case Enums.SQLType.ntext:
        case Enums.SQLType.xml:
            return "string";
        case Enums.SQLType.@char:
            return "char";
        case Enums.SQLType.bigint:
            return "long";
        case Enums.SQLType.bit:
            return "bool";
        case Enums.SQLType.smalldatetime:
        case Enums.SQLType.datetime:
        case Enums.SQLType.date:
        case Enums.SQLType.datetime2:
            return "DateTime";
        case Enums.SQLType.datetimeoffset:
            return "DateTimeOffset";
        case Enums.SQLType.@decimal:
        case Enums.SQLType.money:
        case Enums.SQLType.numeric:
        case Enums.SQLType.smallmoney:
            return "decimal";
        case Enums.SQLType.@float:
            return "double";
        case Enums.SQLType.@int:
            return "int";
        case Enums.SQLType.real:
            return "Single";
        case Enums.SQLType.smallint:
            return "short";
        case Enums.SQLType.uniqueidentifier:
            return "Guid";
        case Enums.SQLType.sql_variant:
            return "object";
        case Enums.SQLType.time:
            return "TimeSpan";
        default:
            throw new Exception("none equal type");
    }
}

public enum SQLType
{
    varbinary,//(1)
    binary,//(1)
    image,
    varchar,
    @char,
    nvarchar,//(1)
    nchar,//(1)
    text,
    ntext,
    uniqueidentifier,
    rowversion,
    bit,
    tinyint,
    smallint,
    @int,
    bigint,
    smallmoney,
    money,
    numeric,
    @decimal,
    real,
    @float,
    smalldatetime,
    datetime,
    sql_variant,
    table,
    cursor,
    timestamp,
    xml,
    date,
    datetime2,
    datetimeoffset,
    filestream,
    time,
}

SQL Server and the .NET Framework are based on different type systems. For example, the .NET Framework Decimal structure has a maximum scale of 28, whereas the SQL Server decimal and numeric data types have a maximum scale of 38. Click Here's a link! for detail

https://msdn.microsoft.com/en-us/library/cc716729(v=vs.110).aspx

In case anybody is looking for methods to convert from/to C# and SQL Server formats, here goes a simple implementation:

private readonly string[] SqlServerTypes = { "bigint", "binary", "bit",  "char", "date",     "datetime", "datetime2", "datetimeoffset", "decimal", "filestream", "float",  "geography",                              "geometry",                              "hierarchyid",                              "image",  "int", "money",   "nchar",  "ntext",  "numeric", "nvarchar", "real",   "rowversion", "smalldatetime", "smallint", "smallmoney", "sql_variant", "text",   "time",     "timestamp", "tinyint", "uniqueidentifier", "varbinary", "varchar", "xml" };
private readonly string[] CSharpTypes    = { "long",   "byte[]", "bool", "char", "DateTime", "DateTime", "DateTime",  "DateTimeOffset", "decimal", "byte[]",     "double", "Microsoft.SqlServer.Types.SqlGeography", "Microsoft.SqlServer.Types.SqlGeometry", "Microsoft.SqlServer.Types.SqlHierarchyId", "byte[]", "int", "decimal", "string", "string", "decimal", "string",   "Single", "byte[]",     "DateTime",      "short",    "decimal",    "object",      "string", "TimeSpan", "byte[]",    "byte",    "Guid",             "byte[]",    "string",  "string" };

public string ConvertSqlServerFormatToCSharp(string typeName)
{
    var index = Array.IndexOf(SqlServerTypes, typeName);

    return index > -1
        ? CSharpTypes[index]
        : "object";
}

public string ConvertCSharpFormatToSqlServer(string typeName)
{
    var index = Array.IndexOf(CSharpTypes, typeName);

    return index > -1
        ? SqlServerTypes[index]
        : null;
}

Edit: fixed typo