TdPeriodDate Structure

TdPeriodDate is a .Net Data Provider for Teradata specific type that represents a duration of time that is bound by beginning and ending dates. The dates are based on the Gregorian calendar.

Object Model

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Structure TdPeriodDate 
   Inherits System.ValueType
   Implements System.Data.SqlTypes.INullable, System.IComparable, System.IComparable(Of TdPeriodDate), System.IConvertible, System.IEquatable(Of TdPeriodDate), System.IFormattable, System.Xml.Serialization.IXmlSerializable

'Usage
 
Dim instance As TdPeriodDate

public struct TdPeriodDate : System.ValueType, System.Data.SqlTypes.INullable, System.IComparable, System.IComparable<TdPeriodDate>, System.IConvertible, System.IEquatable<TdPeriodDate>, System.IFormattable, System.Xml.Serialization.IXmlSerializable

public value class TdPeriodDate : public System.ValueType, System.Data.SqlTypes.INullable, System.IComparable, System.IComparable<TdPeriodDate>, System.IConvertible, System.IEquatable<TdPeriodDate>, System.IFormattable, System.Xml.Serialization.IXmlSerializable

Remarks

The Advanced SQL Engine introduced Period types in release 13.00.00.00. Unfortunately, .NET does not have system types that correspond to any of the the SQL Period types. Therefore, the Data Provider exposes a corresponding provider specific type for each of the period types supported by the SQL Engine.

For the Teradata Period type Period(Date) the provider specific type is TdPeriodDate. This type enables an application to work with data that contain a period of type date.

A period is an anchored duration. It represents a set of contiguous time granules within that duration. In the case of TdPeriodDate, the granularity of the time is represented by a day. The representation of a period is both inclusive and exclusive. It is inclusive in that the duration of the period begins from lower bound up to, but not including (excluding), the ending bound. For example, suppose a TdPeriodDate contains the period of:

   (2007-12-25, 2008-01-01)

The period will include "2007-12-25" and not "2008-01-01". It extends for 7 days.

The components of a period consists of the following:

Time Granule This is the minimum representation of time within a period. For TdPeriodDate, the minimum time representation within a period is one day.
Time Element A Time value that is contained within the period. For example, the time element "2007-12-30" is contained in the period "(2007-12-25, 2008-01-01)". When a period is represented by a TdPeriodDate, the Time Element will be specified using a TdDate.
Beginning Bound The lower bound or the start of the period. Within a period, this value represents the "lowest" time element. The beginning bound must be less than the ending bound.
Ending Bound The upper bound or the ending of the period. The Ending Element is not included in the period. Therefore, No Time Element in the period can be greater or equal to the Ending Bound.
Duration The number of granules in a period. It is represented as a TimeSpan.

A TdPeriodDate can also be specified as an In, Out, or InOut parameter to a Stored Procedure. The data will be returned to an application using either the TdParameter.ProviderSpecificValue or TdParameter.Value property. Retrieving the parameter using TdParameter.ProviderSpecificValue, will return the data using the Period structure. When TdParameter.Value is used, the data is returned as a String (this is the corresponding .Net type).

Example

The following is an example on retrieving a TdPeriodDate, modify the period, and then updating the period.

Public void PeriodDateExample(TdCommand cmd, String studentId)
{
   cmd.Parameter.Clear();
             
   cmd.CommandText = "SELECT timePeriod  " +
                   "FROM ClassDetention " +
                   "WHERE StudentId = ?";
             
   cmd.CommandType = CommandType.Text;
             
   // creating the parameter
   cmd.Parameters.Add(null, TdType.Varchar, 9,
      System.Data.ParameterDirection.Input, true, 0, 0, null,    
      System.Data.DataRowVersion.Default, studentId);
             
   TdPeriodDate detention;
             
   using (TdDataReader dr = cmd.ExecuteReader())
   {
      If (false == dr.Read())
      {
	       return;
      }
   
      // Retrieving the Period
      detention = dr.GetTdPeriodDate(0);
   }
             
   // An additional 5 days will be added to ending bound.
             
   // Specifying a TimeSpan of 5 days
   System.TimeSpan fiveExtraDays = new TimeSpan(5, 0, 0, 0);
             
   // Getting the ending bound of the period and
   // adding 5 days to it
   TdDate endOfDetention = detention.End + fiveExtraDays;
             
   detention = new TdPeriodDate(detention.Begin, endOfDetention);    
             
   cmd.Parameters.Clear();
             
   cmd.CommandText = "UPDATE classDetention " +
                        "SET timePeriod = ? " +
                        "WHERE StudentId = ?";
             
   cmd.Parameters.Add(null, TdType.PeriodDate, 0,
         System.Data.ParameterDirection.Input, true, 0, 0, null,    
         System.Data.DataRowVersion.Default, detention);
             
   cmd.Parameters.Add(null, TdType.Varchar, 9,
         System.Data.ParameterDirection.Input, true, 0, 0, null,    
         System.Data.DataRowVersion.Default, studentId);
             
   cmd.ExecuteNonQuery();
}

Inheritance Hierarchy

System.Object
System.ValueType
Teradata.Client.Provider.TdPeriodDate

Requirements

Target Platforms: Windows 8.1, Windows 10, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019

Reference

TdPeriodDate Members
Teradata.Client.Provider Namespace
TdDate Structure
TdDate Structure
Provider Specific Types: Period Type Overview