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  1. MariaDB Server
  2. MDEV-17182

Move fractional second truncation outside of Field_xxx::store_TIME_with_warn()

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    Description

      This task is self-sufficient change MDEV-16991.

      To make the main MDEV-16991 patch simpler, we'll move fractional second truncation from these methods:

      int Field_timestamp::store_TIME_with_warning()
      		 
      int Field_temporal_with_date::store_TIME_with_warning()
      		 
      int Field_time::store_TIME_with_warning()

      to the caller level. store_TIME_with_warning() will get an already properly truncated value.

      We'll also add truncating constructors for Time and Datetime.

      For example, for Datetime, the new constructors will looks approximately like this:

        Datetime(MYSQL_TIME_STATUS *status,
      		 
                 const char *str, size_t len, CHARSET_INFO *cs,
      		 
                 sql_mode_t fuzzydate, uint dec)
      		 
         :Temporal_with_date(Datetime(status, str, len, cs, fuzzydate))
      		 
        {
      		 
          trunc(dec);
      		 
        }
      		 
        Datetime(int *warn, double nr, sql_mode_t fuzzydate, uint dec)
      		 
         :Temporal_with_date(Datetime(warn, nr, fuzzydate))
      		 
        {
      		 
          trunc(dec);
      		 
        }
      		 
        Datetime(int *warn, const my_decimal *d, sql_mode_t fuzzydate, uint dec)
      		 
         :Temporal_with_date(Datetime(warn, d, fuzzydate))
      		 
        {
      		 
          trunc(dec);
      		 
        }
      		 
        Datetime(THD *thd, int *warn, const MYSQL_TIME *from,
      		 
                 sql_mode_t fuzzydate, uint dec)
      		 
         :Temporal_with_date(Datetime(thd, warn, from, fuzzydate))
      		 
        {
      		 
          trunc(dec);
      		 
        }

      The callers will be changed to truncate the value before passing it to store_TIME_with_warn(). For example, in case of string-to-TIME conversion, the change will look like this:

       int Field_time::store(const char *from,size_t len,CHARSET_INFO *cs)
      		 
       {
      		 
         ErrConvString str(from, len, cs);
      		 
         MYSQL_TIME_STATUS st;
      		 
      -  Time tm(&st, from, len, cs, sql_mode_for_dates(get_thd()));
      		 
      +  Time tm(&st, from, len, cs, sql_mode_for_dates(get_thd()), decimals());
      		 
         return store_TIME_with_warning(&tm, &str, st.warnings);
      		 
       }

      Later, in the main patch for MDEV-16991, all truncating Time and Datetime constructors will be fixed to choose between truncation and rounding, according to the current session options.

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          Task - A task that needs to be done. MDEV-16991 Rounding vs truncation for TIME, DATETIME, TIMESTAMP

          • Major - Major loss of function.
          • Closed
          relates to

          Task - A task that needs to be done. MDEV-17203 Move fractional second truncation from Item_xxx_typecast::get_date() to Time and Datetime constructors

          • Major - Major loss of function.
          • Closed

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              bar Alexander Barkov
              bar Alexander Barkov
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                Updated:
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