SQLConflictAction.update(assignments:predicate:)

Specifies that conflicts this action is applied to shall cause the INSERT to be converted to an UPDATE on the same schema which performs the column updates specified by the associated column assignments and, where supported by the database, constrained by the associated predicate. The column assignments may include SQLExcludedColumn expressions to refer to values which would have been inserted into the row if the conflict had not taken place.

case update(assignments: [any SQLExpression], predicate: (any SQLExpression)?)