SQL Server类型与C#类型对应关系

SQL Server类型	C#类型
bit	bool
tinyint	byte
smallint	short
int	int
bigint	long
real	float
float	double
money	decimal
datetime	DateTime
char	string
varchar	string
nchar	string
nvarchar	string
text	string
ntext	string
image	byte[]
binary	byte[]
uniqueidentifier	Guid

/ SqlDbType转换为C#数据类型

public static Type SqlType2CsharpType(SqlDbType sqlType)
{
    switch (sqlType)
    {
        case SqlDbType.BigInt:
            return typeof(Int64);
        case SqlDbType.Binary:
            return typeof(Object);
        case SqlDbType.Bit:
            return typeof(Boolean);
        case SqlDbType.Char:
            return typeof(String);
        case SqlDbType.DateTime:
            return typeof(DateTime);
        case SqlDbType.Decimal:
            return typeof(Decimal);
        case SqlDbType.Float:
            return typeof(Double);
        case SqlDbType.Image:
            return typeof(Object);
        case SqlDbType.Int:
            return typeof(Int32);
        case SqlDbType.Money:
            return typeof(Decimal);
        case SqlDbType.NChar:
            return typeof(String);
        case SqlDbType.NText:
            return typeof(String);
        case SqlDbType.NVarChar:
            return typeof(String);
        case SqlDbType.Real:
            return typeof(Single);
        case SqlDbType.SmallDateTime:
            return typeof(DateTime);
        case SqlDbType.SmallInt:
            return typeof(Int16);
        case SqlDbType.SmallMoney:
            return typeof(Decimal);
        case SqlDbType.Text:
            return typeof(String);
        case SqlDbType.Timestamp:
            return typeof(Object);
        case SqlDbType.TinyInt:
            return typeof(Byte);
        case SqlDbType.Udt://自定义的数据类型
            return typeof(Object);
        case SqlDbType.UniqueIdentifier:
            return typeof(Object);
        case SqlDbType.VarBinary:
            return typeof(Object);
        case SqlDbType.VarChar:
            return typeof(String);
        case SqlDbType.Variant:
            return typeof(Object);
        case SqlDbType.Xml:
            return typeof(Object);
        default:
            return null;
    }
}

// sql server数据类型（如：varchar）
// 转换为SqlDbType类型
public static SqlDbType SqlTypeString2SqlType(string sqlTypeString)
{
    SqlDbType dbType = SqlDbType.Variant;//默认为Object

    switch (sqlTypeString)
    {
        case "int":
            dbType = SqlDbType.Int;
            break;
        case "varchar":
            dbType = SqlDbType.VarChar;
            break;
        case "bit":
            dbType = SqlDbType.Bit;
            break;
        case "datetime":
            dbType = SqlDbType.DateTime;
            break;
        case "decimal":
            dbType = SqlDbType.Decimal;
            break;
        case "float":
            dbType = SqlDbType.Float;
            break;
        case "image":
            dbType = SqlDbType.Image;
            break;
        case "money":
            dbType = SqlDbType.Money;
            break;
        case "ntext":
            dbType = SqlDbType.NText;
            break;
        case "nvarchar":
            dbType = SqlDbType.NVarChar;
            break;
        case "smalldatetime":
            dbType = SqlDbType.SmallDateTime;
            break;
        case "smallint":
            dbType = SqlDbType.SmallInt;
            break;
        case "text":
            dbType = SqlDbType.Text;
            break;
        case "bigint":
            dbType = SqlDbType.BigInt;
            break;
        case "binary":
            dbType = SqlDbType.Binary;
            break;
        case "char":
            dbType = SqlDbType.Char;
            break;
        case "nchar":
            dbType = SqlDbType.NChar;
            break;
        case "numeric":
            dbType = SqlDbType.Decimal;
            break;
        case "real":
            dbType = SqlDbType.Real;
            break;
        case "smallmoney":
            dbType = SqlDbType.SmallMoney;
            break;
        case "sql_variant":
            dbType = SqlDbType.Variant;
            break;
        case "timestamp":
            dbType = SqlDbType.Timestamp;
            break;
        case "tinyint":
            dbType = SqlDbType.TinyInt;
            break;
        case "uniqueidentifier":
            dbType = SqlDbType.UniqueIdentifier;
            break;
        case "varbinary":
            dbType = SqlDbType.VarBinary;
            break;
        case "xml":
            dbType = SqlDbType.Xml;
            break;
    }
    return dbType;
}

// sql server中的数据类型，转换为C#中的类型类型
public static Type SqlTypeString2CsharpType(string sqlTypeString)
{
    SqlDbType dbTpe = SqlTypeString2SqlType(sqlTypeString);

    return SqlType2CsharpType(dbTpe);
}

// 将sql server中的数据类型，转化为C#中的类型的字符串
public static string SqlTypeString2CsharpTypeString(string sqlTypeString)
{
    Type type = SqlTypeString2CsharpType(sqlTypeString);

    return type.Name;
}