core/sql/common/DTICommonType.cpp

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/* -*-C++-*-
**************************************************************************
*
* File:         DTICommonType.C
* Description:  Common interface to Datetime and Interface types
* Created:      06/13/96
* Language:     C++
*
*
**************************************************************************
*/

// -----------------------------------------------------------------------

#include "DTICommonType.h"
#include "IntervalType.h"
#include "DatetimeType.h"

// ***********************************************************************
//
//  DatetimeIntervalCommonType : static methods
//
// ***********************************************************************

const char* DatetimeIntervalCommonType::getFieldName(rec_datetime_field field)
{
  switch(field) {
  case REC_DATE_YEAR:
    return "YEAR";
  case REC_DATE_MONTH:
    return "MONTH";
  case REC_DATE_DAY:
    return "DAY";
  case REC_DATE_HOUR:
    return "HOUR";
  case REC_DATE_MINUTE:
    return "MINUTE";
  case REC_DATE_SECOND:
    return "SECOND";
  case REC_DATE_FRACTION_MP:
    return "FRACTION";
  case REC_DATE_YEARQUARTER_EXTRACT:
    return "YEARQUARTER";
  case REC_DATE_YEARMONTH_EXTRACT:
    return "YEARMONTH";
  case REC_DATE_YEARWEEK_EXTRACT:
    return "YEARWEEK";
  case REC_DATE_YEARQUARTER_D_EXTRACT:
    return "YEARQUARTERD";
  case REC_DATE_YEARMONTH_D_EXTRACT:
    return "YEARMONTHD";
  case REC_DATE_YEARWEEK_D_EXTRACT:
    return "YEARWEEKD";
  case REC_DATE_CENTURY:
    return "CENTURY";
  case REC_DATE_DECADE:
    return "DECADE";
  case REC_DATE_WEEK:
    return "WEEK";
  case REC_DATE_QUARTER:
    return "QUARTER";
  case REC_DATE_EPOCH:
    return "EPOCH";
  case REC_DATE_DOW:
    return "DOW";
  case REC_DATE_DOY:
    return "DOY";
  case REC_DATE_WOM:
    return "WOM";
  default:
    return NULL;
  }
} // DatetimeIntervalCommonType::getFieldName


// ---------------------------------------------------------------------
// A method which tells if a conversion error can occur when converting
// a value of this type to the target type.
// ---------------------------------------------------------------------
NABoolean DatetimeIntervalCommonType::errorsCanOccur
  (const NAType& target, NABoolean lax) const
{
  if (NAType::errorsCanOccur(target)) { return TRUE; }

  if (target.getTypeQualifier() == NA_DATETIME_TYPE) {
    if (lax) {
      // datetimes that are compared in a bi-relational predicate
      // are always the same. Binder has already checked for this.
      return FALSE;
    } 
    else { // lax is FALSE
      // no error can occur if datatypes are the same
      if ((const DatetimeType&)target == (*this)) return FALSE;
    }
  }
  else {
    // Interval type
    const IntervalType &intervalTarget = (const IntervalType &)target;
    if (*this == intervalTarget)
      return FALSE;   //  no error can occur if datatypes are the same
  }
  return TRUE;
}