sortBy

Returns DataFrame with rows sorted by one or several columns.

By default, columns are sorted in ascending order with null values going first. Available modifiers:

.desc — changes column sort order from ascending to descending
.nullsLast — forces null values to be placed at the end of the order

df.sortBy { age }
df.sortBy { age and name.firstName.desc() }
df.sortBy { weight.nullsLast() }

val age by column<Int>()
val weight by column<Int?>()
val name by columnGroup()
val firstName by name.column<String>()

df.sortBy { age }
df.sortBy { age and firstName }
df.sortBy { weight.nullsLast() }

df.sortBy("age")
df.sortBy { "age" and "name"["firstName"].desc() }
df.sortBy { "weight".nullsLast() }

sortByDesc

Returns DataFrame sorted by one or several columns in descending order.

df.sortByDesc { age and weight }

val age by column<Int>()
val weight by column<Int?>()

df.sortByDesc { age and weight }

df.sortByDesc("age", "weight")

sortWith

Returns DataFrame sorted with comparator.

df.sortWith { row1, row2 ->
    when {
        row1.age < row2.age -> -1
        row1.age > row2.age -> 1
        else -> row1.name.firstName.compareTo(row2.name.firstName)
    }
}

Last modified: 09 December 2024