singleOrNull
Return single element, or null if the sequence is empty or has more than one element.
The operation is terminal.
inline fun <E : Any, T : BaseTable<E>> EntitySequence<E, T>.singleOrNull(predicate: (T) -> ColumnDeclaring<Boolean>): E?(source)
Return the single element matching the given predicate, or null if element was not found or more than one element was found.
The operation is terminal.
