Package dev.frostlake.functions.scalar.conditional

Class OrderingCoercion

java.lang.Object
dev.frostlake.functions.scalar.conditional.OrderingCoercion
public final class OrderingCoercion extends Object
How GREATEST and LEAST order arguments that are not already the same family. They do not merely compare — they CONVERT, and the account's answers say which way: 
   GREATEST(n, '5')            5          the string joins the number, whichever side it is on
   GREATEST('5', n)            5          — still INTEGER, not the first argument's VARCHAR
   GREATEST(d, '2027-01-01')   2027-01-01 a date the same way, both orders
   GREATEST(bo, n)             TRUE       BOOLEAN wins over NUMBER, whichever side it is on
   GREATEST(v, n)              1          a scalar VARIANT unwraps to its value
   GREATEST(n, 2.5)            2.5        two numerics compare by VALUE, not by Java class
   GREATEST(n, s)              "Numeric value 'abc' is not recognized"   — a ROW-time value error

The string rule is the set operation's rule, and it is literally the same code (SetOperations.coerceStringToLeadingType(java.lang.Object, java.lang.String)) so the two surfaces cannot drift: a string beside another family converts to that family, and a conversion that fails carries the account's own sentence rather than a Java one.

What CANNOT be brought together — a BINARY beside anything else — is signalled with IncomparableArgumentsException instead of being guessed at. The refusal the account gives there names the operand and its DECLARED type, which only the expression tree knows, so the evaluator re-asks the static channel for the wording. Comparing them as text, the way an ORDER BY comparator would, is exactly the leniency this replaced.

  • Method Details

    • coerceAll

      public static List<Object> coerceAll(List<Object> args)
      Every argument converted to the family they will be ordered in — which is also the family of the ANSWER. Live returns the CONVERTED value, not the winning argument as it was written: GREATEST(n, '5') answers the NUMBER 5, not the string, and GREATEST(n, bo) answers TRUE rather than the 1 that outranked nothing. Converting first and ordering after is what makes those two agree.
      Parameters:
      args - the call's arguments, nulls included
      Returns:
      a list of the same size, each value in the common family