Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>This is an implementation in C# of how to parse and convert a DateTime to and from its RFC-822 representation. The only restriction it has is that the DateTime is in Coordinated Universal Time (UTC). I agree that this is not very elegant code, but it does the job.</p> <pre><code>/// &lt;summary&gt; /// Provides methods for converting &lt;see cref="DateTime"/&gt; structures /// to and from the equivalent &lt;a href="http://www.w3.org/Protocols/rfc822/#z28"&gt;RFC 822&lt;/a&gt; /// string representation. /// &lt;/summary&gt; public class Rfc822DateTime { //============================================================ // Private members //============================================================ #region Private Members /// &lt;summary&gt; /// Private member to hold array of formats that RFC 822 date-time representations conform to. /// &lt;/summary&gt; private static string[] formats = new string[0]; /// &lt;summary&gt; /// Private member to hold the DateTime format string for representing a DateTime in the RFC 822 format. /// &lt;/summary&gt; private const string format = "ddd, dd MMM yyyy HH:mm:ss K"; #endregion //============================================================ // Public Properties //============================================================ #region Rfc822DateTimeFormat /// &lt;summary&gt; /// Gets the custom format specifier that may be used to represent a &lt;see cref="DateTime"/&gt; in the RFC 822 format. /// &lt;/summary&gt; /// &lt;value&gt;A &lt;i&gt;DateTime format string&lt;/i&gt; that may be used to represent a &lt;see cref="DateTime"/&gt; in the RFC 822 format.&lt;/value&gt; /// &lt;remarks&gt; /// &lt;para&gt; /// This method returns a string representation of a &lt;see cref="DateTime"/&gt; that utilizes the time zone /// offset (local differential) to represent the offset from Greenwich mean time in hours and minutes. /// The &lt;see cref="Rfc822DateTimeFormat"/&gt; is a valid date-time format string for use /// in the &lt;see cref="DateTime.ToString(String, IFormatProvider)"/&gt; method. /// &lt;/para&gt; /// &lt;para&gt; /// The &lt;a href="http://www.w3.org/Protocols/rfc822/#z28"&gt;RFC 822&lt;/a&gt; Date and Time specification /// specifies that the year will be represented as a two-digit value, but the /// &lt;a href="http://www.rssboard.org/rss-profile#data-types-datetime"&gt;RSS Profile&lt;/a&gt; recommends that /// all date-time values should use a four-digit year. The &lt;see cref="Rfc822DateTime"/&gt; class /// follows the RSS Profile recommendation when converting a &lt;see cref="DateTime"/&gt; to the equivalent /// RFC 822 string representation. /// &lt;/para&gt; /// &lt;/remarks&gt; public static string Rfc822DateTimeFormat { get { return format; } } #endregion #region Rfc822DateTimePatterns /// &lt;summary&gt; /// Gets an array of the expected formats for RFC 822 date-time string representations. /// &lt;/summary&gt; /// &lt;value&gt; /// An array of the expected formats for RFC 822 date-time string representations /// that may used in the &lt;see cref="DateTime.TryParseExact(String, string[], IFormatProvider, DateTimeStyles, out DateTime)"/&gt; method. /// &lt;/value&gt; /// &lt;remarks&gt; /// The array of the expected formats that is returned assumes that the RFC 822 time zone /// is represented as or converted to a local differential representation. /// &lt;/remarks&gt; /// &lt;seealso cref="ConvertZoneToLocalDifferential(String)"/&gt; public static string[] Rfc822DateTimePatterns { get { if (formats.Length &gt; 0) { return formats; } else { formats = new string[35]; // two-digit day, four-digit year patterns formats[0] = "ddd',' dd MMM yyyy HH':'mm':'ss'.'fffffff zzzz"; formats[1] = "ddd',' dd MMM yyyy HH':'mm':'ss'.'ffffff zzzz"; formats[2] = "ddd',' dd MMM yyyy HH':'mm':'ss'.'fffff zzzz"; formats[3] = "ddd',' dd MMM yyyy HH':'mm':'ss'.'ffff zzzz"; formats[4] = "ddd',' dd MMM yyyy HH':'mm':'ss'.'fff zzzz"; formats[5] = "ddd',' dd MMM yyyy HH':'mm':'ss'.'ff zzzz"; formats[6] = "ddd',' dd MMM yyyy HH':'mm':'ss'.'f zzzz"; formats[7] = "ddd',' dd MMM yyyy HH':'mm':'ss zzzz"; // two-digit day, two-digit year patterns formats[8] = "ddd',' dd MMM yy HH':'mm':'ss'.'fffffff zzzz"; formats[9] = "ddd',' dd MMM yy HH':'mm':'ss'.'ffffff zzzz"; formats[10] = "ddd',' dd MMM yy HH':'mm':'ss'.'fffff zzzz"; formats[11] = "ddd',' dd MMM yy HH':'mm':'ss'.'ffff zzzz"; formats[12] = "ddd',' dd MMM yy HH':'mm':'ss'.'fff zzzz"; formats[13] = "ddd',' dd MMM yy HH':'mm':'ss'.'ff zzzz"; formats[14] = "ddd',' dd MMM yy HH':'mm':'ss'.'f zzzz"; formats[15] = "ddd',' dd MMM yy HH':'mm':'ss zzzz"; // one-digit day, four-digit year patterns formats[16] = "ddd',' d MMM yyyy HH':'mm':'ss'.'fffffff zzzz"; formats[17] = "ddd',' d MMM yyyy HH':'mm':'ss'.'ffffff zzzz"; formats[18] = "ddd',' d MMM yyyy HH':'mm':'ss'.'fffff zzzz"; formats[19] = "ddd',' d MMM yyyy HH':'mm':'ss'.'ffff zzzz"; formats[20] = "ddd',' d MMM yyyy HH':'mm':'ss'.'fff zzzz"; formats[21] = "ddd',' d MMM yyyy HH':'mm':'ss'.'ff zzzz"; formats[22] = "ddd',' d MMM yyyy HH':'mm':'ss'.'f zzzz"; formats[23] = "ddd',' d MMM yyyy HH':'mm':'ss zzzz"; // two-digit day, two-digit year patterns formats[24] = "ddd',' d MMM yy HH':'mm':'ss'.'fffffff zzzz"; formats[25] = "ddd',' d MMM yy HH':'mm':'ss'.'ffffff zzzz"; formats[26] = "ddd',' d MMM yy HH':'mm':'ss'.'fffff zzzz"; formats[27] = "ddd',' d MMM yy HH':'mm':'ss'.'ffff zzzz"; formats[28] = "ddd',' d MMM yy HH':'mm':'ss'.'fff zzzz"; formats[29] = "ddd',' d MMM yy HH':'mm':'ss'.'ff zzzz"; formats[30] = "ddd',' d MMM yy HH':'mm':'ss'.'f zzzz"; formats[31] = "ddd',' d MMM yy HH':'mm':'ss zzzz"; // Fall back patterns formats[32] = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffffffK"; // RoundtripDateTimePattern formats[33] = DateTimeFormatInfo.InvariantInfo.UniversalSortableDateTimePattern; formats[34] = DateTimeFormatInfo.InvariantInfo.SortableDateTimePattern; return formats; } } } #endregion //============================================================ // Public Methods //============================================================ #region Parse(string s) /// &lt;summary&gt; /// Converts the specified string representation of a date and time to its &lt;see cref="DateTime"/&gt; equivalent. /// &lt;/summary&gt; /// &lt;param name="s"&gt;A string containing a date and time to convert.&lt;/param&gt; /// &lt;returns&gt; /// A &lt;see cref="DateTime"/&gt; equivalent to the date and time contained in &lt;paramref name="s"/&gt;, /// expressed as &lt;i&gt;Coordinated Universal Time (UTC)&lt;/i&gt;. /// &lt;/returns&gt; /// &lt;remarks&gt; /// The string &lt;paramref name="s"/&gt; is parsed using formatting information in the &lt;see cref="DateTimeFormatInfo.InvariantInfo"/&gt; object. /// &lt;/remarks&gt; /// &lt;exception cref="ArgumentNullException"&gt;&lt;paramref name="s"/&gt; is a &lt;b&gt;null&lt;/b&gt; reference (Nothing in Visual Basic).&lt;/exception&gt; /// &lt;exception cref="ArgumentNullException"&gt;&lt;paramref name="s"/&gt; is an empty string.&lt;/exception&gt; /// &lt;exception cref="FormatException"&gt;&lt;paramref name="s"/&gt; does not contain a valid RFC 822 string representation of a date and time.&lt;/exception&gt; public static DateTime Parse(string s) { //------------------------------------------------------------ // Validate parameter //------------------------------------------------------------ if (String.IsNullOrEmpty(s)) { throw new ArgumentNullException("s"); } DateTime result; if (Rfc822DateTime.TryParse(s, out result)) { return result; } else { throw new FormatException(String.Format(null, "{0} is not a valid RFC 822 string representation of a date and time.", s)); } } #endregion #region ConvertZoneToLocalDifferential(string s) /// &lt;summary&gt; /// Converts the time zone component of an RFC 822 date and time string representation to its local differential (time zone offset). /// &lt;/summary&gt; /// &lt;param name="s"&gt;A string containing an RFC 822 date and time to convert.&lt;/param&gt; /// &lt;returns&gt;A date and time string that uses local differential to describe the time zone equivalent to the date and time contained in &lt;paramref name="s"/&gt;.&lt;/returns&gt; /// &lt;exception cref="ArgumentNullException"&gt;&lt;paramref name="s"/&gt; is a &lt;b&gt;null&lt;/b&gt; reference (Nothing in Visual Basic).&lt;/exception&gt; /// &lt;exception cref="ArgumentNullException"&gt;&lt;paramref name="s"/&gt; is an empty string.&lt;/exception&gt; public static string ConvertZoneToLocalDifferential(string s) { string zoneRepresentedAsLocalDifferential = String.Empty; //------------------------------------------------------------ // Validate parameter //------------------------------------------------------------ if (String.IsNullOrEmpty(s)) { throw new ArgumentNullException("s"); } if(s.EndsWith(" UT", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" UT") + 1) ), "+00:00"); } else if (s.EndsWith(" GMT", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" GMT") + 1 ) ), "+00:00"); } else if (s.EndsWith(" EST", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" EST") + 1)), "-05:00"); } else if (s.EndsWith(" EDT", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" EDT") + 1)), "-04:00"); } else if (s.EndsWith(" CST", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" CST") + 1)), "-06:00"); } else if (s.EndsWith(" CDT", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" CDT") + 1)), "-05:00"); } else if (s.EndsWith(" MST", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" MST") + 1)), "-07:00"); } else if (s.EndsWith(" MDT", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" MDT") + 1)), "-06:00"); } else if (s.EndsWith(" PST", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" PST") + 1)), "-08:00"); } else if (s.EndsWith(" PDT", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" PDT") + 1)), "-07:00"); } else if (s.EndsWith(" Z", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" Z") + 1)), "+00:00"); } else if (s.EndsWith(" A", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" A") + 1)), "-01:00"); } else if (s.EndsWith(" M", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" M") + 1)), "-12:00"); } else if (s.EndsWith(" N", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" N") + 1)), "+01:00"); } else if (s.EndsWith(" Y", StringComparison.OrdinalIgnoreCase)) { zoneRepresentedAsLocalDifferential = String.Concat(s.Substring(0, (s.LastIndexOf(" Y") + 1)), "+12:00"); } else { zoneRepresentedAsLocalDifferential = s; } return zoneRepresentedAsLocalDifferential; } #endregion #region ToString(DateTime utcDateTime) /// &lt;summary&gt; /// Converts the value of the specified &lt;see cref="DateTime"/&gt; object to its equivalent string representation. /// &lt;/summary&gt; /// &lt;param name="utcDateTime"&gt;The Coordinated Universal Time (UTC) &lt;see cref="DateTime"/&gt; to convert.&lt;/param&gt; /// &lt;returns&gt;A RFC 822 string representation of the value of the &lt;paramref name="utcDateTime"/&gt;.&lt;/returns&gt; /// &lt;exception cref="ArgumentException"&gt;The specified &lt;paramref name="utcDateTime"/&gt; object does not represent a &lt;see cref="DateTimeKind.Utc"&gt;Coordinated Universal Time (UTC)&lt;/see&gt; value.&lt;/exception&gt; public static string ToString(DateTime utcDateTime) { if (utcDateTime.Kind != DateTimeKind.Utc) { throw new ArgumentException("utcDateTime"); } return utcDateTime.ToString(Rfc822DateTime.Rfc822DateTimeFormat, DateTimeFormatInfo.InvariantInfo); } #endregion #region TryParse(string s, out DateTime result) /// &lt;summary&gt; /// Converts the specified string representation of a date and time to its &lt;see cref="DateTime"/&gt; equivalent. /// &lt;/summary&gt; /// &lt;param name="s"&gt;A string containing a date and time to convert.&lt;/param&gt; /// &lt;param name="result"&gt; /// When this method returns, contains the &lt;see cref="DateTime"/&gt; value equivalent to the date and time /// contained in &lt;paramref name="s"/&gt;, expressed as &lt;i&gt;Coordinated Universal Time (UTC)&lt;/i&gt;, /// if the conversion succeeded, or &lt;see cref="DateTime.MinValue"&gt;MinValue&lt;/see&gt; if the conversion failed. /// The conversion fails if the s parameter is a &lt;b&gt;null&lt;/b&gt; reference (Nothing in Visual Basic), /// or does not contain a valid string representation of a date and time. /// This parameter is passed uninitialized. /// &lt;/param&gt; /// &lt;returns&gt;&lt;b&gt;true&lt;/b&gt; if the &lt;paramref name="s"/&gt; parameter was converted successfully; otherwise, &lt;b&gt;false&lt;/b&gt;.&lt;/returns&gt; /// &lt;remarks&gt; /// The string &lt;paramref name="s"/&gt; is parsed using formatting information in the &lt;see cref="DateTimeFormatInfo.InvariantInfo"/&gt; object. /// &lt;/remarks&gt; public static bool TryParse(string s, out DateTime result) { //------------------------------------------------------------ // Attempt to convert string representation //------------------------------------------------------------ bool wasConverted = false; result = DateTime.MinValue; if (!String.IsNullOrEmpty(s)) { DateTime parseResult; if (DateTime.TryParseExact(Rfc822DateTime.ConvertZoneToLocalDifferential(s), Rfc822DateTime.Rfc822DateTimePatterns, DateTimeFormatInfo.InvariantInfo, DateTimeStyles.AdjustToUniversal, out parseResult)) { result = DateTime.SpecifyKind(parseResult, DateTimeKind.Utc); wasConverted = true; } } return wasConverted; } #endregion } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POHow do I parse and convert DateTime’s to the RFC 822 date-time format?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USOppositional
    1. USOppositional
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POHow do I parse and convert DateTime’s to the RFC 822 date-time format?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    1. COThis code looks horrible.
      singulars
      1. PO
      1. USEsko
    2. COThe use of the `Guard` type in this code reminds me of the solution in the Argotic Syndication Framework. Is this beta code from Argotic? Their solution to this problem in the latest version of Argotic is best I've seen.
      singulars
      1. PO
      1. USrasx
    3. COThis isn't beta code from Argotic, and I believe the latest of Argotic probobly has a better implmeentation than the one outlined here.
      singulars
      1. PO
      1. USOppositional
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload