将日期作为字符串存储会导致混乱，因为在不识别所使用日历系统的情况下日期毫无意义。CADatetime 示例定义两个用户定义数据类型（CADatetime 和 CADate），通过它们可以按日历方式对日期和时间进行处理。
先决条件
若要创建和运行此项目，必须安装下列软件：
SQL Server 或 SQL Server Express。 您可以从 SQL Server Express Documentation and Samples （Express 文档和示例）网站免费获取 SQL Server Express。
SQL Server 开发人员网站提供的 AdventureWorks 数据库
.NET Framework SDK 2.0 或更高版本，或 Microsoft Visual Studio 2005 或更高版本。 您可以免费获取 .NET Framework SDK。
此外，还必须满足以下条件：
您使用的 SQL Server 实例必须已启用 CLR 集成。
若要启用 CLR 集成，请执行以下步骤：
启用 CLR 集成
- 执行以下 Transact-SQL 命令：
sp_configure 'clr enabled', 1
GO
RECONFIGURE
GO
.gif "注意")
注意若要启用 CLR，您必须具有 ALTER SETTINGS 服务器级别权限，sysadmin 和 serveradmin 固定服务器角色的成员隐式拥有该权限。
必须在您使用的 SQL Server 实例上安装 AdventureWorks 数据库。
如果您不是要使用的 SQL Server 实例的管理员，则必须让管理员授予您 CreateAssembly 权限，才能完成安装。
生成示例
按照以下说明创建和运行该示例：
打开 Visual Studio 或 .NET Framework 命令提示符。
如有必要，为您的示例创建目录。 对于此示例，我们将使用 C:\MySample。
在 c:\MySample 中，创建 CalendarAware.cs 并将 C# 示例代码（如下所示）复制到该文件中。
在 c:\MySample 中，创建文件 calendars.txt 并将示例代码复制到该文件中。
在 c:\MySample 中，创建文件 calendars.ar-SA.txt 并将以下代码复制到该文件中：
; the default calendar for this culture
DefaultCalendarID = 1
在 c:\MySample 中，创建文件 calendars.ja.txt 并将以下代码复制到该文件中：
; the default calendar for this culture
DefaultCalendarID = 3
在 c:\MySample 中，创建文件 calendars. zh-CN.txt 并将以下代码复制到该文件中：
; the default calendar for this culture
DefaultCalendarID = 8
在 c:\MySample 中，创建文件 build.com 并将以下代码复制到该文件中：
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
通过在命令提示符处执行文件生成操作来生成附属程序集。
通过在命令行提示符处执行以下命令来编译示例代码：
- 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
将 Transact-SQL 安装代码复制到一个文件中，并在示例目录中将其另存为 Install.sql。
如果该示例安装在 C:\MySample\ 之外的目录中，请按说明编辑文件 Install.sql 以指向该位置。
通过执行以下命令部署程序集和存储过程：
- sqlcmd -E -I -i install.sql
将 Transact-SQL 测试命令脚本复制到一个文件中，并在示例目录中将其另存为 test.sql。
使用以下命令执行测试脚本：
- sqlcmd -E -I -i test.sql
将 Transact-SQL 清除脚本复制到一个文件中，并在示例目录中将其另存为 cleanup.sql。
使用以下命令执行该脚本：
- sqlcmd -E -I -i cleanup.sql
示例代码
下面是此示例的代码列表。
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);
}
}
这是定义日历所需的文件 calendars.txt。
; 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
这是 Transact-SQL 安装脚本 (Install.sql)，该脚本在数据库中部署程序集并创建转换函数；它还创建了示例数据表。
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
这是 test.sql，该脚本通过对多个日历执行函数来测试该示例。
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
下面的 Transact-SQL 从数据库中删除程序集、函数和表。
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