Package dev.frostlake.functions.scalar.conversion

Class TimestampFlavourConversion

java.lang.Object
dev.frostlake.functions.scalar.conversion.TimestampFlavourConversion
public final class TimestampFlavourConversion extends Object
The one conversion behind TO_TIMESTAMP and its TRY_ twins, handing back the value the call's flavour holds: a TIMESTAMP_NTZ is a wall clock, a TIMESTAMP_LTZ the instant the input names shown in the session's zone, and a TIMESTAMP_TZ that instant at an offset it keeps. What the input IS decides the instant and, for a TZ, the offset: 
   input                   TIMESTAMP_LTZ                        TIMESTAMP_TZ
   a number (any scale)    the epoch, in the session's zone     the epoch, at the session's offset
   a string of digits      the epoch, in the session's zone     the epoch, at UTC
   text with no offset     a wall clock in the session's zone   the same, at the session's offset
   text with an offset     re-expressed in the session's zone   kept as written

So under America/Los_Angeles TO_TIMESTAMP_TZ(1579046400) is 2020-01-14 16:00:00 -0800 and TO_TIMESTAMP_TZ('1579046400') is 2020-01-15 00:00:00 Z: one instant, two offsets. A VARIANT is read by what it holds — a number as a number (seconds, never unit-detected), a string as text, the JSON null as NULL — and any other variant is refused. Live-verified, every cell.

  • Method Details

    • castVariant

      public static Object castVariant(String flavour, VariantValue variant)
      A VARIANT cast to a timestamp flavour, which reads it exactly as the flavour's conversion function does: a number is an epoch in seconds, the instant in the session's zone, and a boolean or a container fails the cast (live-verified).
      Parameters:
      flavour - TIMESTAMP_NTZ, TIMESTAMP_LTZ or TIMESTAMP_TZ
      variant - the value to convert
      Returns:
      the value in the flavour's carrier, or null for the JSON null