distinct
Removes duplicate rows. The rows in the resulting DataFrame are in the same order as they were in the original DataFrame.
df.distinct()
If columns are specified, resulting DataFrame will have only given columns with distinct values.
df.distinct { age and name }
// same as
df.select { age and name }.distinct()
val age by column<Int>()
val name by columnGroup()
df.distinct { age and name }
// same as
df.select { age and name }.distinct()
df.distinct("age", "name")
// same as
df.select("age", "name").distinct()
distinctBy
Keep only the first row for every group of rows grouped by some condition.
df.distinctBy { age and name }
// same as
df.groupBy { age and name }.mapToRows { group.first() }
val age by column<Int>()
val name by columnGroup()
val firstName by name.column<String>()
df.distinctBy { age and name }
// same as
df.groupBy { age and name }.mapToRows { group.first() }
df.distinctBy("age", "name")
// same as
df.groupBy("age", "name").mapToRows { group.first() }
Last modified: 27 September 2024