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Образец определяемого пользователем типа данных даты и времени с учетом календаря

Сохранение дат в виде строк может приводить к недоразумениям, потому что даты теряют смысл, если неизвестно, какой календарь используется. Образец CADatetime определяет два определяемых пользователем типа данных, CADatetime и CADate, обеспечивающих обработку даты и времени с учетом календаря.

Предварительные требования

Для создания и запуска этого проекта должно быть установлено следующее программное обеспечение:

  • SQL Server или SQL Server Express. SQL Server Express можно получить бесплатно с веб-сайтадокументации и образцов SQL Server Express (возможно, на английском языке)

  • База данных AdventureWorks, которая доступна на веб-сайте разработки SQL Server (возможно, на английском языке).

  • Пакет SDK 2.0 для платформы .NET Framework или более поздняя версия либо среда Microsoft Visual Studio 2005 или более поздняя версия. Пакет SDK для платформы .NET Framework можно получить бесплатно.

  • Кроме того, должны выполняться следующие условия.

  • Для используемого экземпляра SQL Server должна быть включена интеграция со средой CLR.

  • Чтобы включить интеграцию со средой CLR, выполните следующие действия.

    Включение интеграции со средой CLR

    • Выполните следующие команды Transact-SQL:

    sp_configure 'clr enabled', 1

    GO

    RECONFIGURE

    GO

    ПримечаниеПримечание

    Чтобы включить CLR, необходимо иметь разрешение ALTER SETTINGS на уровне сервера, которое неявно назначается членам предопределенных ролей сервера sysadmin и serveradmin.

  • На используемом экземпляре SQL Server должна быть установлена база данных AdventureWorks.

  • Если вы не являетесь администратором используемого экземпляра SQL Server, то для завершения установки необходимо, чтобы администратор предоставил разрешение CreateAssembly .

Построение образца

Создайте и запустите образец в соответствии со следующими инструкциями.

  1. Откройте командную строку Visual Studio или .NET Framework.

  2. Если необходимо, создайте каталог для своего образца. В данном примере будет использоваться каталог C:\MySample.

  3. В каталоге c:\MySample создайте файл CalendarAware.cs и скопируйте в него образец кода (C#), приведенный ниже.

  4. В каталоге c:\MySample создайте файл calendars.txt и скопируйте в него образец кода.

  5. В каталоге c:\MySample создайте файл calendars.ar-SA.txt и скопируйте в него следующий код.

    • ; the default calendar for this culture

    • DefaultCalendarID = 1

  6. В каталоге c:\MySample создайте файл calendars.ja.txt и скопируйте в него следующий код.

    • ; the default calendar for this culture

    • DefaultCalendarID = 3

  7. В каталоге c:\MySample создайте файл calendars. zh-CN.txt и скопируйте в него следующий код.

    • ; the default calendar for this culture

    • DefaultCalendarID = 8

  8. В каталоге c:\MySample создайте файл build.com и скопируйте в него следующий код.

    • resgen calendars.txt

    • resgen calendars.ar-SA.txt

    • resgen calendars.ja.txt

    • resgen calendars.zh-CN.txt

    • al /t:lib /culture:ar-SA /embed:calendars.ar-SA.resources /out:CADatetime.resources.ar-SA.dll

    • al /t:lib /culture:ja /embed:calendars.ja.resources /out:CADatetime.resources.ja.dll

    • al /t:lib /culture:zh-CN /embed:calendars.zh-CN.resources /out:CADatetime.resources.zh-CN.dll

    • al /t:lib /culture:"" /embed:calendars.resources /out:CADatetime.resources.dll

  9. Постройте сборки дополнений, выполнив построение файла из командной строки.

  10. Скомпилируйте образец кода из командной строки, выполнив следующую команду.

    • Csc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.XML.dll /out:CADateTime.dll /target:library CalendarAwareDate.cs
  11. Скопируйте код установки Transact-SQL в файл и сохраните его в файле Install.sql в том же каталоге.

  12. Если образец установлен в каталоге, отличном от C:\MySample\, внесите изменения в файл Install.sql, указав там этот каталог.

  13. Разверните сборку и хранимую процедуру, выполнив

    • sqlcmd -E -I -i install.sql
  14. Скопируйте скрипт проверки Transact-SQL в файл и сохраните его в файле test.sql в том же каталоге.

  15. Выполните скрипт проверки следующей командой

    • sqlcmd -E -I -i test.sql
  16. Скопируйте скрипт очистки Transact-SQL в файл и сохраните его в файле cleanup.sql в том же каталоге.

  17. Выполните скрипт следующей командой

    • sqlcmd -E -I -i cleanup.sql

Образец кода

Ниже приведены листинги кода для данного образца.

C#

    using System;
    using System.Data.Sql;
    using System.Data.SqlTypes;
    using System.Globalization;
    using System.Resources;
    using System.Text;
    using System.Reflection;
    using System.Collections.Generic;
    using System.Xml;
    using System.Xml.Serialization;
    using System.Xml.Schema;
    using System.IO;

[assembly: System.Resources.NeutralResourcesLanguage("", System.Resources.UltimateResourceFallbackLocation.Satellite)]


    /// <summary>
    /// A date value in the specified calendar system.
    /// </summary>
    [Serializable]
    [Microsoft.SqlServer.Server.SqlUserDefinedType(Microsoft.SqlServer.Server.Format.Native, IsByteOrdered = true)]
    public struct CADate : INullable, IXmlSerializable
    {
        // This type uses days == 0 as the way to designate a NULL value

        const string CADateSchema =
            "<xs:schema targetNamespace=\"https://schemas.microsoft.com/sqlserver/2004/08/CADate\" " +
                "xmlns=\"https://schemas.microsoft.com/sqlserver/2004/07/CADate\" " +
                "elementFormDefault=\"qualified\"" +
                "xmlns:xs=\"http://www.w3.org/2001/XMLSchema\" >" +
                "<xs:element name=\"CADate\" >" +
                    "<xs:complexType mixed=\"true\" >" +
                        "<xs:attribute name=\"IsNull\" use=\"required\" type=\"xs:boolean\" />" +
                        "<xs:attribute name=\"Year\" type=\"xs:int\"/>" +
                        "<xs:attribute name=\"Month\" type=\"xs:int\"/>" +
                        "<xs:attribute name=\"Day\" type=\"xs:int\"/>" +
                        "<xs:attribute name=\"Calendar\" type=\"xs:string\"/>" +
                    "</xs:complexType>" +
                "</xs:element>" +
            "</xs:schema>";

        private const uint NullDay = 0;

        private static readonly char[] dateChars = new char[] { 'd', 'M', 'y' };
        private static readonly char[] allowedSinglePatternChars = new char[] { 'd', 'D', 'm', 'M', 'y', 'Y', '/', '%' };
        private static readonly char[] allowedDoublePatternChars = new char[] { 'g', '\\' };

        /// <summary>
        ///     Each tick is 100 nanoseconds.  This conversion factor when multipled by the number of
        ///     days yields the number of ticks which make up that day.  Ticks are interesting as they
        ///     can be used to construct DateTime instances in order to perform various date based computations.
        /// </summary>
        private const long DaysToTicksConversionFactor = 10L * 1000L * 1000L * 60L * 60L * 24L;

        /// <summary>
        /// The number of days since the calendar started (January 1, 1)
        /// </summary>
        private uint days;

        /// <summary>
        /// Which calendar is used for this date and time
        /// </summary>
        private byte calendarId;

        /// <summary>
        /// construct a CADate from the specified datetime using the default calendar.
        /// </summary>
        /// <param name="dt">DateTime</param>
        public CADate(DateTime dt)
            : this(dt, CalendarInfo.DefaultCalendarId)
        {
        }

        /// <summary>
        /// Construct a calendar aware date for the specified year/month/day using the default calendar
        /// </summary>
        /// <param name="year"></param>
        /// <param name="month"></param>
        /// <param name="day"></param>
        public CADate(int year, int month, int day)
            : this(new DateTime(year, month, day, CalendarInfo.DefaultCalendar))
        {
        }

        /// <summary>
        ///     Converts a DateTime instance and a calendar into a calendar aware date instance.
        /// </summary>
        /// <param name="dt">A specific point in time</param>
        /// <param name="calendarId">A specific calendar system</param>
        private CADate(DateTime dt, int calendarId)
        {
            this.days = (uint)(dt.Ticks / DaysToTicksConversionFactor);
            this.calendarId = (byte)calendarId;
        }

        /// <summary>
        /// the current CADate
        /// </summary>
        /// <value></value>
        public static CADate Now
        {
            get
            {
                return new CADate(DateTime.Now);
            }
        }

        public static string CurrentCalendarName
        {
            get
            {
                return CalendarInfo.DefaultCalendar.GetType().Name;
            }
        }

        /// <summary>
        /// return the null value for this type
        /// </summary>
        /// <value></value>
        public static CADate Null
        {
            get
            {
                CADate caDate = new CADate();
                caDate.days = NullDay;

                return caDate;
            }
        }

        /// <summary>
        /// is this value null
        /// </summary>
        /// <value></value>
        public bool IsNull
        {
            get
            {
                return this.days == NullDay;
            }
        }

        public Calendar Calendar
        {
            get
            {
                return CalendarInfo.Calendars[this.calendarId];
            }
        }

        public string CalendarName
        {
            get
            {
                return this.Calendar.GetType().Name;
            }
        }

        // Accessors for parts of the date 

        public int Year
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetYear(this.DateTime);
            }
        }

        public int Month
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetMonth(this.DateTime);
            }
        }

        public int DayOfMonth
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetDayOfMonth(this.DateTime);
            }
        }

        public int Day
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetDayOfYear(this.DateTime);
            }
        }

    
        public uint Days
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.days;
            }
        }

        /// <summary>
        /// convert to datetime
        /// </summary>
        /// <value></value>
        public DateTime DateTime
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return new DateTime(this.Days * DaysToTicksConversionFactor);
            }
        }

        /// <summary>
        /// parse the given string and return a calendar aware date.
        /// </summary>
        /// <param name="sqlString"></param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = false,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADate Parse(SqlString sqlString)
        {
            if (sqlString.IsNull)
            {
                return CADate.Null;
            }

            return new CADate(DateTime.Parse(sqlString.Value, DateTimeFormatInfo.CurrentInfo));
        }

        /// <summary>
        /// Construct a CADate from the specified format, using the current culture
        /// </summary>
        /// <param name="data">the string to be parsed</param>
        /// <param name="format">the format string</param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = true,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADate ParseUsingFormat(string data, string format)
        {
            if (data == null || format == null)
            {
                return CADate.Null;
            }

            return new CADate(
                DateTime.ParseExact(
                data,
                FilterDateFormat(format),
                DateTimeFormatInfo.CurrentInfo));
        }

        // The following methods are intended to be callable from tsql.  That is why they are static.

        /// <summary>
        /// Create a new CADate from a SqlDateTime
        /// </summary>
        /// <param name="sqlDateTime"></param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = false,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADate FromSqlDateTime(SqlDateTime sqlDateTime)
        {
            if (sqlDateTime.IsNull)
            {
                return CADate.Null;
            }

            return new CADate(sqlDateTime.Value);
        }

        /// <summary>
        /// Creates a CADateTime from a Sql DateTime instance and a specific calendar.
        /// </summary>
        /// <param name="sqlDateTime">When</param>
        /// <param name="calendarName">The short name of the desired calendar</param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = true, IsMutator = false, IsPrecise = false,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADate FromSqlDateTimeAndCalendar(SqlDateTime sqlDateTime, string calendarName)
        {
            return new CADate(sqlDateTime.Value, CalendarInfo.GetCalendarId(calendarName));
        }

        /// <summary>
        /// Create a new CADate from the year/month/day
        /// </summary>
        /// <param name="year"></param>
        /// <param name="month"></param>
        /// <param name="day"></param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = true,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADate FromYearMonthDay(int year, int month, int day)
        {
            return new CADate(year, month, day);
        }

        public static SqlBoolean operator ==(CADate xCADate, CADate yCADate)
        {
            if (xCADate.IsNull || yCADate.IsNull)
            {
                return SqlBoolean.Null;
            }

            return xCADate.DateTime == yCADate.DateTime;
        }

        public static SqlBoolean operator !=(CADate xCADate, CADate yCADate)
        {
            if (xCADate.IsNull || yCADate.IsNull)
            {
                return SqlBoolean.Null;
            }

            return xCADate.DateTime != yCADate.DateTime;
        }

        // Conversions to other representations of the date

        /// <summary>
        /// convert the date to string
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            if (this.IsNull)
            {
                return null;
            }

            return string.Format(
                CultureInfo.CurrentUICulture,
                DayMonthYearFormatString(),
                this.DayOfMonth,
                this.Month,
                this.Year);
        }

        /// <summary>
        /// Return a string representation of this date, in the Gregorian calendarId
        /// </summary>
        /// <returns></returns>
        public string ToGregorianString()
        {
            if (this.IsNull)
            {
                return null;
            }

            return this.DateTime.ToString("d", DateTimeFormatInfo.CurrentInfo);
        }

        /// <summary>
        /// Convert the date to string, using the specified format
        /// </summary>
        /// <param name="format">Format string</param>
        /// <returns></returns>
        public string ToGregorianStringUsingFormat(string format)
        {
            if (this.IsNull)
            {
                return null;
            }

            return this.DateTime.ToString(
                FilterDateFormat(format),
                DateTimeFormatInfo.CurrentInfo);
        }

        /// <summary>
        /// Convert to sql datetime
        /// </summary>
        /// <returns></returns>
        public SqlDateTime ToSqlDateTime()
        {
            return new SqlDateTime(this.DateTime);
        }

        // Manipulation of date parts

        public CADate AddYears(int years)
        {
            return new CADate(this.Calendar.AddYears(this.DateTime, years));
        }

        public CADate AddDays(int daysToAdd)
        {
            return new CADate(this.Calendar.AddDays(this.DateTime, daysToAdd));
        }

        public CADate AddMonths(int months)
        {
            return new CADate(this.Calendar.AddMonths(this.DateTime, months));
        }

        public double DiffDays(CADate other)
        {
            return this.DateTime.Subtract(other.DateTime).TotalDays;
        }

        // Hashing and comparison methods

        public override int GetHashCode()
        {
            return this.DateTime.GetHashCode();
        }

        public override bool Equals(object obj)
        {
            if (!(obj is DateTime))
            {
                return false;
            }

            DateTime dt = (DateTime)obj;
            return this.DateTime.Equals(dt);
        }

        public XmlSchema GetSchema()
        {
            StringReader sr = new StringReader(CADateSchema);
            XmlSchema schema = XmlSchema.Read(
                sr,
                new ValidationEventHandler(this.ValidationHandler));
            sr.Dispose();

            return schema;
        }

        public void ReadXml(XmlReader reader)
        {
            if (reader == null)
            {
                throw new ArgumentNullException("reader");
            }

            reader.MoveToContent();
            if (reader.GetAttribute("IsNull").Equals("true"))
            {
                this.days = NullDay;
            }
            else
            {
                string calendarName = reader.GetAttribute("Calendar");
                Calendar requestedCalendar 
                    = CalendarInfo.Calendars[CalendarInfo.GetCalendarId(calendarName)];

                this.days = (uint)(new DateTime(
                    int.Parse(
                        reader.GetAttribute("Year"),
                        CultureInfo.CurrentUICulture),
                    int.Parse(
                        reader.GetAttribute("Month"), 
                        CultureInfo.CurrentUICulture),
                    int.Parse(
                        reader.GetAttribute("Day"), 
                        CultureInfo.CurrentUICulture),
                        requestedCalendar).Ticks / DaysToTicksConversionFactor);
            }
        }

        public void WriteXml(XmlWriter writer)
        {
            if (writer == null)
            {
                throw new ArgumentNullException("writer");
            }

            writer.WriteStartElement(
                "CADate",
                "https://schemas.microsoft.com/sqlserver/2004/08/CADate");
            writer.WriteAttributeString("IsNull", this.IsNull.ToString(CultureInfo.CurrentUICulture));
            if (!this.IsNull)
            {
                writer.WriteAttributeString("Year", this.Year.ToString(CultureInfo.CurrentUICulture));
                writer.WriteAttributeString("Month", this.Month.ToString(CultureInfo.CurrentUICulture));
                writer.WriteAttributeString("Day", this.Day.ToString(CultureInfo.CurrentUICulture));
                writer.WriteAttributeString("Calendar", this.Calendar.GetType().ToString());
            }

            writer.WriteEndElement();
        }

        // DateTime.ParseExact takes a "format" string which describes how to present the date and time.
        // This method filters out any formatting characters which conflict 
        private static string FilterDateFormat(string format)
        {
            StringBuilder sb = new StringBuilder(format.Length);
            for (int i = 0; i < format.Length; i++)
            {
                char element = format[i];
                bool doubled = (i + 1 < format.Length)
                    && (element.Equals(format[i + 1]) || element.Equals('\\'));
                if (Array.IndexOf<char>(allowedSinglePatternChars, element) > -1 ||
                    char.IsWhiteSpace(element))
                {
                    sb.Append(element);
                }
                else if (doubled && (Array.IndexOf<char>(allowedDoublePatternChars, element) > -1))
                {
                    sb.Append(element);
                    sb.Append(format[++i]);
                }
            }

            return sb.ToString();
        }

        // Returns a string suitable for use with string.Format which displays
        // day, month, and year components in a culture appropriate way.
        private static string DayMonthYearFormatString()
        {
            string cultureDatePattern = CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern;
            return CalendarInfo.SubstitutePositionForCharacters(dateChars, cultureDatePattern);
        }

        
        private void ValidationHandler(object sender, ValidationEventArgs args)
        {
            throw new ApplicationException(args.Message);
        }
    }
    public static class CalendarInfo
    {
        public const byte MaxCalendarId = 0xff;
        private readonly static char[] stringFormatChars; // = new char[] { 't' };
        private static readonly Calendar defaultCalendar; // = new GregorianCalendar();
        private static readonly int defaultCalendarId;
        private static readonly Calendar[] calendars;

        /// <summary>
        /// Initialize the calendar array, one for each possible calendar
        /// </summary>
        static CalendarInfo()
        {
            stringFormatChars = new char[] { 't' };

            ResourceManager rm = new ResourceManager("calendars", Assembly.GetExecutingAssembly());

            int numCalendars = int.Parse(rm.GetString("NumCalendars"), CultureInfo.CurrentUICulture);
            if (numCalendars > MaxCalendarId)
            {
                throw new ArgumentOutOfRangeException("Does not support more than 255 calendars");
            }

            calendars = new Calendar[numCalendars];
            for (int i = 0; i < numCalendars; i++)
            {
                string typeName = rm.GetString(i.ToString(CultureInfo.CurrentUICulture));
                calendars[i] = (Calendar)Activator.CreateInstance(Type.GetType(typeName, true));
            }

            defaultCalendarId = int.Parse(rm.GetString("DefaultCalendarID"), CultureInfo.CurrentUICulture);
            defaultCalendar = calendars[defaultCalendarId];
        }

        public static Calendar DefaultCalendar
        {
            get
            {
                return CalendarInfo.defaultCalendar;
            }
        }

        public static int DefaultCalendarId
        {
            get
            {
                return CalendarInfo.defaultCalendarId;
            }
        }

     
        public static Calendar[] Calendars
        {
            get
            {
                return CalendarInfo.calendars;
            }
        }

    
        public static int GetCalendarId(string calendarName)
        {
            for (int i = 0; i < calendars.Length; i++)
            {
                if (calendars[i].GetType().Name == calendarName)
                {
                    return i;
                }
            }

            throw new ArgumentException("Unknown calendar: " + calendarName);
        }

        // Returns a string suitable for use with string.Format which displays
        // either date or datetime components in a culture appropriate way.
        public static string SubstitutePositionForCharacters(Char[] characters, string pattern)
        {
            StringBuilder sb = new StringBuilder();
            char lastChar = ' ';
            for (int i = 0; i < pattern.Length; i++)
            {
                char c = pattern[i];
                int position = Array.IndexOf<char>(characters, c);
                if (position != -1)
                {
                    if (lastChar != c)
                    {
                        sb.Append('{');
                        sb.Append(position);

                        // If this isn't a string format char, it is a numeric format char.
                        // In that case we need to get the correct number of digits from
                        // the pattern.
                        if (Array.IndexOf<char>(stringFormatChars, c) == -1)
                        {
                            // Decimal number with the appropriate minimum number of digits
                            sb.AppendFormat(":d{0:d}", CountRun(c, pattern, i));
                        }

                        sb.Append('}');
                    }
                }
                else
                {
                    sb.Append(c);
                }

                lastChar = c;
            }

            return sb.ToString();
        }

        // Given that you have found character c in a pattern, count how many instances of that
        // character occur at that position before another character or the end of the string is reached.
        
        public static int CountRun(char chr, string pattern, int start)
        {
            if (pattern == null)
            {
                throw new ArgumentNullException("pattern");
            }

            int result = 1;
            for (int i = start + 1; i < pattern.Length; i++)
            {
                if (pattern[i] == chr)
                {
                    result += 1;
                }
                else
                {
                    break;
                }
            }

            return result;
        }
    }
    /// <summary>
    /// A datetime value in the specified calendar system.
    /// </summary>
    [Serializable]
    [Microsoft.SqlServer.Server.SqlUserDefinedType(Microsoft.SqlServer.Server.Format.Native, IsByteOrdered = true, ValidationMethodName = "IsValid")]
    public struct CADateTime : INullable, IXmlSerializable
    {
        const string CADateTimeSchema =
            "<xs:schema targetNamespace=\"https://schemas.microsoft.com/sqlserver/2004/08/CADateTime\" " +
                "xmlns=\"https://schemas.microsoft.com/sqlserver/2004/07/CADate\" " +
                "elementFormDefault=\"qualified\"" +
                "xmlns:xs=\"http://www.w3.org/2001/XMLSchema\" >" +
                "<xs:element name=\"CADate\" >" +
                    "<xs:complexType mixed=\"true\" >" +
                        "<xs:attribute name=\"IsNull\" use=\"required\" type=\"xs:boolean\" />" +
                        "<xs:attribute name=\"Year\" type=\"xs:int\"/>" +
                        "<xs:attribute name=\"Month\" type=\"xs:int\"/>" +
                        "<xs:attribute name=\"Day\" type=\"xs:int\"/>" +
                        "<xs:attribute name=\"Hour\" type=\"xs:int\">" +
                        "<xs:attribute name=\"Minute\" type=\"xs:int\">" +
                        "<xs:attribute name=\"Second\" type=\"xs:int\">" +
                        "<xs:attribute name=\"Calendar\" type=\"xs:string\"/>" +
                    "</xs:complexType>" +
                "</xs:element>" +
            "</xs:schema>";

        static readonly char[] datetimeChars = new char[] { 'd', 'M', 'y', 'h', 'H', 'm', 's', 't' };

        // This type uses ticks == 0 as the way to designate a NULL value
        private const long NullTicks = 0;

        /// <summary>
        /// What date and time this is as ticks from midnight January 1, 1
        /// </summary>
        private long dtTicks;

        /// <summary>
        /// Which calendar is used for this date and time
        /// </summary>
        private byte calendarId;

        /// <summary>
        /// Construct a CADateTime from the specified datetime using the default calendar.
        /// </summary>
        /// <param name="dt">DateTime</param>
        public CADateTime(DateTime dt)
            : this(dt, CalendarInfo.DefaultCalendarId)
        {
        }

        /// <summary>
        /// Construct a calendar aware datetime for the specified year/month/day using the default calendar
        /// </summary>
        /// <param name="year"></param>
        /// <param name="month"></param>
        /// <param name="day"></param>
        public CADateTime(int year, int month, int day)
            : this(new DateTime(year, month, day, CalendarInfo.DefaultCalendar))
        {
        }

        /// <summary>
        ///     Converts a DateTime instance and a calendar into a calendar aware datetime instance.
        /// </summary>
        /// <param name="dt">A specific point in time</param>
        /// <param name="calendarId">A specific calendar system</param>
        private CADateTime(DateTime dt, int calendarId)
        {
            this.dtTicks = dt.Ticks;
            this.calendarId = (byte)calendarId;
        }

        /// <summary>
        /// return the null value for this type
        /// </summary>
        /// <value></value>
        public static CADateTime Null
        {
            get
            {
                CADateTime dt = new CADateTime();
                dt.dtTicks = NullTicks;

                return dt;
            }
        }

        /// <summary>
        /// the current CADateTime
        /// </summary>
        /// <value></value>
        public static CADateTime Now
        {
            get
            {
                return new CADateTime(DateTime.Now);
            }
        }

        public static string CurrentCalendarName
        {
            get
            {
                return CalendarInfo.DefaultCalendar.GetType().Name;
            }
        }

        /// <summary>
        /// is this value null
        /// </summary>
        /// <value></value>
        public bool IsNull
        {
            get
            {
                return this.Ticks == NullTicks;
            }
        }

        public int Year
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetYear(this.DateTime);
            }
        }

        public int Month
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetMonth(this.DateTime);
            }
        }

        public int DayOfMonth
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetDayOfMonth(this.DateTime);
            }
        }

        public int Day
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetDayOfYear(this.DateTime);
            }
        }

        public int Hour
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetHour(this.DateTime);
            }
        }

        public int Minute
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetMinute(this.DateTime);
            }
        }

        public int Second
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetSecond(this.DateTime);
            }
        }

        /// <summary>
        /// Milliseconds
        /// </summary>
        /// <value></value>
        public double Milliseconds
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.Calendar.GetMilliseconds(this.DateTime);
            }
        }

        public long Ticks
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get
            {
                return this.dtTicks;
            }
        }

        /// <summary>
        /// convert to datetime
        /// </summary>
        /// <value></value>
        public DateTime DateTime
        {
            [Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
            get { return new DateTime(this.dtTicks); }
        }

        public Calendar Calendar
        {
            get
            {
                return CalendarInfo.Calendars[this.calendarId];
            }
        }

        public string CalendarName
        {
            get
            {
                return this.Calendar.GetType().Name;
            }
        }

        /// <summary>
        /// parse the given string and return a calendar aware datetime.
        /// </summary>
        /// <param name="sqlString"></param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = true,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADateTime Parse(SqlString sqlString)
        {
            if (sqlString.IsNull)
            {
                return CADateTime.Null;
            }

            return new CADateTime(
                DateTime.Parse(
                    sqlString.Value,
                    DateTimeFormatInfo.CurrentInfo));
        }

        /// <summary>
        /// Construct a CADateTime from the specified format, using the current culture
        /// </summary>
        /// <param name="data">the string to be parsed</param>
        /// <param name="format">the format string</param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = true,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADateTime ParseUsingFormat(string data, string format)
        {
            if (data == null || format == null)
            {
                return CADateTime.Null;
            }

            return new CADateTime(DateTime.ParseExact(data, format, DateTimeFormatInfo.CurrentInfo));
        }

        /// <summary>
        /// Create a new CADateTime from a SqlDateTime
        /// </summary>
        /// <param name="sqlDateTime"></param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = true,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADateTime FromSqlDateTime(SqlDateTime sqlDateTime)
        {
            if (sqlDateTime.IsNull)
            {
                return CADateTime.Null;
            }

            return new CADateTime(sqlDateTime.Value);
        }

        /// <summary>
        /// Creates a CADateTime from a Sql DateTime instance and a specific calendar.
        /// </summary>
        /// <param name="sqlDateTime">When</param>
        /// <param name="calendarName">The short name of the desired calendar</param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = true, IsMutator = false, IsPrecise = true,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADateTime FromSqlDateTimeAndCalendar(SqlDateTime sqlDateTime, string calendarName)
        {
            return new CADateTime(sqlDateTime.Value, CalendarInfo.GetCalendarId(calendarName));
        }

        /// <summary>
        /// Create a new CADateTime from the year/month/day
        /// </summary>
        /// <param name="year"></param>
        /// <param name="month"></param>
        /// <param name="day"></param>
        /// <returns></returns>
        [Microsoft.SqlServer.Server.SqlMethod(DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, IsDeterministic = false, IsMutator = false, IsPrecise = true,
        SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
        public static CADateTime FromYearMonthDay(int year, int month, int day)
        {
            return new CADateTime(year, month, day);
        }

        public static SqlBoolean operator ==(CADateTime xCADateTime, CADateTime yCADateTime)
        {
            if (xCADateTime.IsNull || yCADateTime.IsNull)
            {
                return SqlBoolean.Null;
            }

            return xCADateTime.DateTime == yCADateTime.DateTime;
        }

        public static SqlBoolean operator !=(CADateTime xCADateTime, CADateTime yCADateTime)
        {
            if (xCADateTime.IsNull || yCADateTime.IsNull)
            {
                return SqlBoolean.Null;
            }

            return xCADateTime.DateTime != yCADateTime.DateTime;
        }

        /// <summary>
        /// convert the datetime to string
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            if (this.IsNull)
            {
                return null;
            }

            bool afternoon = this.Hour >= 12;
            int twelveHour = this.Hour;
            if (twelveHour == 0)
            {
                twelveHour = 12;
            }
            else if (twelveHour > 12)
            {
                twelveHour = twelveHour - 12;
            }

            return string.Format(
                CultureInfo.CurrentCulture,
                DateTimeFormatString(),
                this.DayOfMonth,
                this.Month,
                this.Year,
                twelveHour,
                this.Hour,
                this.Minute,
                this.Second,
                afternoon
                    ? CultureInfo.CurrentCulture.DateTimeFormat.PMDesignator
                    : CultureInfo.CurrentCulture.DateTimeFormat.AMDesignator);
        }

        /// <summary>
        /// convert the datetime to string, using the specified format
        /// </summary>
        /// <param name="format">Format string</param>
        /// <returns></returns>
        public string ToGregorianStringUsingFormat(string format)
        {
            if (this.IsNull)
            {
                return null;
            }

            return this.DateTime.ToString(format, DateTimeFormatInfo.CurrentInfo);
        }

        /// <summary>
        /// Return a string representation of this DateTime, in the Gregorian calendarId
        /// </summary>
        /// <returns></returns>
        public string ToGregorianString()
        {
            if (this.IsNull)
            {
                return null;
            }

            return this.DateTime.ToString(DateTimeFormatInfo.CurrentInfo);
        }

        public bool IsValid()
        {
            return this.dtTicks >= 0;
        }

        /// <summary>
        /// convert to sql datetime
        /// </summary>
        /// <returns></returns>
        public SqlDateTime ToSqlDateTime()
        {
            return new SqlDateTime(this.DateTime);
        }

        public CADateTime AddYears(int years)
        {
            return new CADateTime(this.Calendar.AddYears(this.DateTime, years));
        }

        public CADateTime AddDays(int days)
        {
            return new CADateTime(this.Calendar.AddDays(this.DateTime, days));
        }

        public CADateTime AddMonths(int months)
        {
            return new CADateTime(this.Calendar.AddMonths(this.DateTime, months));
        }

        public CADateTime AddHours(int hours)
        {
            return new CADateTime(this.Calendar.AddHours(this.DateTime, hours));
        }

        public CADateTime AddMinutes(int minutes)
        {
            return new CADateTime(this.Calendar.AddMinutes(this.DateTime, minutes));
        }

        public CADateTime AddSeconds(int seconds)
        {
            return new CADateTime(this.Calendar.AddSeconds(this.DateTime, seconds));
        }

        public CADateTime AddMilliseconds(double millis)
        {
            return new CADateTime(this.Calendar.AddMilliseconds(this.DateTime, millis));
        }

        public double DiffDays(CADateTime other)
        {
            return this.DateTime.Subtract(other.DateTime).TotalDays;
        }

        public double DiffHours(CADateTime other)
        {
            return this.DateTime.Subtract(other.DateTime).TotalHours;
        }

        public double DiffMinutes(CADateTime other)
        {
            return this.DateTime.Subtract(other.DateTime).TotalMinutes;
        }

        public double DiffSeconds(CADateTime other)
        {
            return this.DateTime.Subtract(other.DateTime).TotalSeconds;
        }

        public double DiffMilliseconds(CADateTime other)
        {
            return this.DateTime.Subtract(other.DateTime).TotalMilliseconds;
        }

        // Hash and comparison operators

        public override int GetHashCode()
        {
            return this.DateTime.GetHashCode();
        }

        public override bool Equals(object obj)
        {
            if (!(obj is DateTime))
            {
                return false;
            }

            DateTime dt = (DateTime)obj;
            return this.DateTime.Equals(dt);
        }

        public XmlSchema GetSchema()
        {
            StringReader sr = new StringReader(CADateTimeSchema);
            XmlSchema schema = XmlSchema.Read(
                sr,
                new ValidationEventHandler(this.ValidationHandler));
            sr.Dispose();

            return schema;
        }

        public void ReadXml(XmlReader reader)
        {
            if (reader == null)
            {
                throw new ArgumentNullException("reader");
            }

            reader.MoveToContent();
            if (reader.GetAttribute("IsNull").Equals("true"))
            {
                this.dtTicks = CADateTime.NullTicks;
            }
            else
            {
                string calendarName = reader.GetAttribute("Calendar");
                Calendar requestedCalendar
                    = CalendarInfo.Calendars[CalendarInfo.GetCalendarId(calendarName)];

                this.dtTicks = (uint)new DateTime(
                    int.Parse(reader.GetAttribute("Year"), CultureInfo.CurrentCulture),
                    int.Parse(reader.GetAttribute("Month"), CultureInfo.CurrentCulture),
                    int.Parse(reader.GetAttribute("Day"), CultureInfo.CurrentCulture),
                    int.Parse(reader.GetAttribute("Hour"), CultureInfo.CurrentCulture),
                    int.Parse(reader.GetAttribute("Minute"), CultureInfo.CurrentCulture),
                    int.Parse(reader.GetAttribute("Second"), CultureInfo.CurrentCulture),
                    requestedCalendar).Ticks;
            }
        }

        public void WriteXml(XmlWriter writer)
        {
            if (writer == null)
            {
                throw new ArgumentNullException("writer");
            }

            writer.WriteStartElement("CADate", "https://schemas.microsoft.com/sqlserver/2004/08/CADate");
            writer.WriteAttributeString("IsNull", this.IsNull.ToString());

            if (!this.IsNull)
            {
                writer.WriteAttributeString("Year", this.Year.ToString(CultureInfo.CurrentUICulture));
                writer.WriteAttributeString("Month", this.Month.ToString(CultureInfo.CurrentUICulture));
                writer.WriteAttributeString("Day", this.Day.ToString(CultureInfo.CurrentUICulture));
                writer.WriteAttributeString("Calendar", Calendar.GetType().ToString());
            }

            writer.WriteEndElement();
        }

        // Returns a string suitable for use with string.Format which displays
        // day, month, and year components in a culture appropriate way.
        private static string DateTimeFormatString()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append(CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern);
            sb.Append(" ");
            sb.Append(CultureInfo.CurrentCulture.DateTimeFormat.LongTimePattern);
            string cultureDatePattern = sb.ToString();

            return CalendarInfo.SubstitutePositionForCharacters(datetimeChars, cultureDatePattern);
        }

      
        private void ValidationHandler(object sender, ValidationEventArgs args)
        {
            throw new ApplicationException(args.Message);
        }
    }

Это файл calendars.txt, требуемый для определения календарей.

; the list of calendars
; the key is the calendar ID, the value is the assembly-qualified name of the type
NumCalendars = 9

; Note, new calendars _MUST_ be added to the end of this list
0 = System.Globalization.GregorianCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089

; Saudi Hijri, the business calendar for use in Saudi Arabia
1 = System.Globalization.UmAlQuraCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089

; HijriCalendar 
2 = System.Globalization.HijriCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089

; other calendars
3 = System.Globalization.JapaneseCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089
4 = System.Globalization.JulianCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089
5 = System.Globalization.KoreanCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089
6 = System.Globalization.TaiwanCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089
7 = System.Globalization.ThaiBuddhistCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089
8 = System.Globalization.ChineseLunisolarCalendar, mscorlib, Version=2.0.3600.0, Culte=neutral, PublicKeyToken=b77a5c561934e089

; the default calendar for this culture
DefaultCalendarID = 0

Это установочный скрипт Transact-SQL (Install.sql), который выполняет развертывание сборок и создает в базе данных функции преобразования. Кроме того, он создает таблицы с образцами данных.

USE AdventureWorks
GO

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ufn_CADateFromSqlDateTimeAndCalendar]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].[ufn_CADateFromSqlDateTimeAndCalendar];
GO

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ufn_CADateTimeFromSqlDateTimeAndCalendar]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].[ufn_CADateTimeFromSqlDateTimeAndCalendar];
GO

IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = OBJECT_ID(N'[Sales].[SalesSummary]') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)
DROP TABLE [Sales].[SalesSummary];
GO

IF EXISTS (SELECT * FROM sys.types WHERE [name] = N'CADateTime') 
DROP TYPE CADateTime;
GO

IF EXISTS (SELECT * FROM sys.types WHERE [name] = N'CADate') 
DROP TYPE CADate;
GO

-- If the assembly we want to add already exists, drop it.

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime')
DROP ASSEMBLY CADateTime;
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.neutral')
DROP ASSEMBLY [CADateTime.resources.neutral];
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.ar-SA')
DROP ASSEMBLY [CADateTime.resources.ar-SA];
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.ja')
DROP ASSEMBLY [CADateTime.resources.ja];
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.zh-CN')
DROP ASSEMBLY [CADateTime.resources.zh-CN];
GO

-- Add the assembly which contains the CLR methods we want to invoke on the server.
DECLARE @SamplesPath nvarchar(1024);
-- You may need to modify the value of the this variable if you have installed the sample someplace other than the default location.
Set @SamplesPath= N'C:\MySample\'

CREATE ASSEMBLY CADateTime
FROM @SamplesPath + 'CADateTime.dll'
WITH permission_set = safe;


CREATE ASSEMBLY [CADateTime.resources.neutral]  
FROM @SamplesPath + 'CADateTime.resources.dll'
WITH permission_set = safe;


CREATE ASSEMBLY [CADateTime.resources.ar-SA]  
FROM @SamplesPath + 'CADateTime.resources.ar-SA.dll'
WITH permission_set = safe;


CREATE ASSEMBLY [CADateTime.resources.ja]  
FROM @SamplesPath + 'CADateTime.resources.ja.dll'
WITH permission_set = safe;

CREATE ASSEMBLY [CADateTime.resources.zh-CN]  
FROM @SamplesPath + 'CADateTime.resources.zh-CN.dll'
WITH permission_set = safe;
GO

CREATE TYPE CADateTime EXTERNAL NAME CADateTime.[CADateTime];
GO

CREATE TYPE CADate EXTERNAL NAME CADateTime.[CADate];
GO

CREATE FUNCTION [dbo].[ufn_CADateFromSqlDateTimeAndCalendar]
(
    @D datetime,
    @CalendarName nvarchar(128)
) 
RETURNS CADate 
AS EXTERNAL NAME CADateTime.[CADate].FromSqlDateTimeAndCalendar;
GO

CREATE FUNCTION [dbo].[ufn_CADateTimeFromSqlDateTimeAndCalendar]
(
    @D datetime,
    @CalendarName nvarchar(128)
) 
RETURNS CADateTime
AS EXTERNAL NAME CADateTime.[CADateTime].FromSqlDateTimeAndCalendar;
GO

SELECT SalesOrderID, [dbo].[ufn_CADateTimeFromSqlDateTimeAndCalendar](OrderDate, 'GregorianCalendar') AS OrderDate, TotalDue 
INTO [Sales].[SalesSummary]
FROM [Sales].[SalesOrderHeader];
GO

ALTER TABLE [Sales].[SalesSummary] WITH CHECK ADD 
    CONSTRAINT [PK_SalesSummary_SalesOrderID] PRIMARY KEY CLUSTERED 
    (
        [SalesOrderID]
    );
GO


ALTER TABLE [Sales].[SalesSummary] ADD DayOfYear AS [OrderDate].[Day] PERSISTED;
GO
 
CREATE INDEX IX_Sales_SalesSummary ON [Sales].[SalesSummary] (DayOfYear);
GO

Это скрипт test.sql, который проверяет образец, выполняя его для различных календарей.

USE AdventureWorks
GO

SELECT CADateTime::CurrentCalendarName;

-- Simple usage, create a new value from a string and print it out
-- We're using ISO 8601 format dates as input, which are YYYY-MM-DD
DECLARE @h CADateTime;
SET @h = '1976-01-02';
SELECT CAST(@h as nvarchar(128)), @h.CalendarName;
GO

-- print it out in "full format"
DECLARE @h CADateTime;
SET @h = '1976-01-02';
SELECT @h.ToGregorianStringUsingFormat('F');
GO

-- print it out in a custom format
DECLARE @h CADateTime;
SET @h = '1976-01-02';
SELECT @h.ToGregorianStringUsingFormat('MMM dd yyyy');
GO

-- convert it to arabic (for testing purposes)
DECLARE @h CADateTime;
SET @h = CADateTime::Parse('1976-01-02');
SELECT @h.ToString(), @h.ToGregorianStringUsingFormat('F');
GO

-- convert sql datetime to CAD and back
DECLARE @h CADateTime;
SET @h = CADateTime::FromSqlDateTime(GetDate());
SELECT @h.ToString(), @h.ToSqlDateTime();
GO

-- get the current CAD, in two ways
SELECT   CADateTime::Now.ToString(), 
    CADateTime::FromSqlDateTime(GetDate()).ToString();
GO

-- do some arithmetic
DECLARE @h CADateTime, @d datetime;
SET @h = CADateTime::Now; -- get the current hijri datetime
SET @h = @h.AddDays(10); -- add ten days to it
SET @d = GetDate(); -- current sql date
SET @d = DateAdd(day, 10, @d); -- add ten days to the sql datetime
-- print 'em both, should be the same
SELECT @h.ToSqlDateTime(), @d;
GO

-- what about datepart
DECLARE @h CADateTime;
SET @h = CADateTime::Now; -- get the current datetime
SELECT @h.Year as year, @h.Month as month, @h.Day as dayofyear, @h.DayOfMonth as dom;
GO

-- print the same date in four different calendars
SELECT 
    CADateTime::FromSqlDateTimeAndCalendar(GetDate(), 'UmAlQuraCalendar').ToString() as Umq,
    CADateTime::FromSqlDateTimeAndCalendar(GetDate(), 'GregorianCalendar').ToString() as Gregorian,
    CADateTime::FromSqlDateTimeAndCalendar(GetDate(), 'JapaneseCalendar').ToString() as Japanese,
    CADateTime::FromSqlDateTimeAndCalendar(GetDate(), 'ChineseLunisolarCalendar').ToString() as ChineseLunisolar;
GO

SELECT CADate::CurrentCalendarName;

-- simple usage, create a new value from a string and print it out
DECLARE @h CADate;
SET @h = '1976-01-02';
SELECT CAST(@h as nvarchar(128)), @h.CalendarName;
GO

-- print it out in "date format"
DECLARE @h CADate;
SET @h = '1976-01-02';
SELECT @h.ToGregorianStringUsingFormat('d');
GO

-- print it out in a custom format
DECLARE @h CADate;
SET @h = '1976-01-02';
SELECT @h.ToGregorianStringUsingFormat('MMM dd yyyy');
GO

-- convert it to arabic (for testing purposes)
DECLARE @h CADate;
SET @h = CADate::Parse('1976-01-02');
SELECT @h.ToString(), @h.ToGregorianStringUsingFormat('d');
GO

-- convert sql datetime to CAD and back
DECLARE @h CADate;
SET @h = CADate::FromSqlDateTime(GetDate());
SELECT @h.ToString(), @h.ToSqlDateTime();
GO

-- get the current CAD, in two ways
SELECT   CADate::Now.ToString(), 
    CADate::FromSqlDateTime(GetDate()).ToString();
GO

-- do some arithmetic
DECLARE @h CADate, @d datetime;
SET @h = CADate::Now; -- get the current hijri datetime
SET @h = @h.AddDays(10); -- add ten days to it
SET @d = GetDate(); -- current sql date
SET @d = DateAdd(day, 10, @d); -- add ten days to the sql datetime
-- print 'em both, should be the same
SELECT @h.ToSqlDateTime(), @d;
GO

-- what about datepart
DECLARE @h CADate;
SET @h = CADate::Now; -- get the current datetime
SELECT @h.Year as year, @h.Month as month, @h.Day as dayofyear, @h.DayOfMonth as dom;
GO

-- print the same date in four different calendars
SELECT 
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'UmAlQuraCalendar').ToString() as Umq,
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'GregorianCalendar').ToString() as Gregorian,
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'JapaneseCalendar').ToString() as Japanese,
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'ChineseLunisolarCalendar').ToString() as ChineseLunisolar;
GO

-- Show the total sales figures for particular days of the year over a 90 day 
-- range starting with day 90.
SELECT DayOfYear, SUM(TotalDue)
FROM [Sales].[SalesSummary]
WHERE DayOfYear >= 90 AND DayOfYear < 180
GROUP BY DayOfYear
ORDER BY DayOfYear;
GO

-- Show the first day of the year where there is sales between day 90 and day 180.
SELECT TOP 1 DayOfYear 
FROM [Sales].[SalesSummary]
WHERE DayOfYear >= 90 AND DayOfYear < 180 
ORDER BY DayOfYear ASC
GO

SET LANGUAGE French
GO

-- print the same date in four different calendars using the French culture
SELECT 
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'UmAlQuraCalendar').ToString() as Umq,
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'GregorianCalendar').ToString() as Gregorian,
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'JapaneseCalendar').ToString() as Japanese,
    CADate::FromSqlDateTimeAndCalendar(GetDate(), 'ChineseLunisolarCalendar').ToString() as ChineseLunisolar;
GO

SET LANGUAGE us_english
GO

Следующий скрипт Transact-SQL удаляет из базы данных сборки, функции и таблицу.

USE AdventureWorks
GO

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ufn_CADateFromSqlDateTimeAndCalendar]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].[ufn_CADateFromSqlDateTimeAndCalendar];
GO

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[ufn_CADateTimeFromSqlDateTimeAndCalendar]') AND type in (N'FN', N'IF', N'TF', N'FS', N'FT'))
DROP FUNCTION [dbo].[ufn_CADateTimeFromSqlDateTimeAndCalendar];
GO

IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = OBJECT_ID(N'[Sales].[SalesSummary]') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)
DROP TABLE [Sales].[SalesSummary];
GO

IF EXISTS (SELECT * FROM sys.types WHERE [name] = N'CADateTime') 
DROP TYPE CADateTime;
GO

IF EXISTS (SELECT * FROM sys.types WHERE [name] = N'CADate') 
DROP TYPE CADate;
GO

-- If the assembly we want to add already exists, drop it.

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime')
DROP ASSEMBLY CADateTime;
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.neutral')
DROP ASSEMBLY [CADateTime.resources.neutral];
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.ar-SA')
DROP ASSEMBLY [CADateTime.resources.ar-SA];
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.ja')
DROP ASSEMBLY [CADateTime.resources.ja];
GO

IF EXISTS (SELECT [name] FROM sys.assemblies WHERE [name] = N'CADateTime.resources.zh-CN')
DROP ASSEMBLY [CADateTime.resources.zh-CN];
GO

См. также

Основные понятия

Сценарии использования и примеры интеграции со средой CLR