Introduction

Following are sort functions

| SPARK SQL SORT FUNCTION SYNTAX | SPARK FUNCTION DESCRIPTION | | ---------------------------------------------- | ------------------------------------------------------------------------------------------------- | | asc(columnName: String): Column | asc function is used to specify the ascending order of the sorting column on DataFrame or DataSet | | asc_nulls_first(columnName: String): Column | Similar to asc function but null values return first and then non-null values | | asc_nulls_last(columnName: String): Column | Similar to asc function but non-null values return first and then null values | | desc(columnName: String): Column | desc function is used to specify the descending order of the DataFrame or DataSet sorting column. | | desc_nulls_first(columnName: String): Column | Similar to desc function but null values return first and then non-null values. | | desc_nulls_last(columnName: String): Column | Similar to desc function but non-null values return first and then null values. |

asc() – ascending function

asc function is used to specify the ascending order of the sorting column on DataFrame or DataSet.

Example in Java:

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.functions;

public class SortFunctions {
    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder()
                .appName("SortFunctionsExample")
                .master("local")
                .getOrCreate();

        Dataset<Row> df = spark.createDataset(Arrays.asList(
                RowFactory.create(1, "apple"),
                RowFactory.create(3, "banana"),
                RowFactory.create(2, "lemon")
        ), Encoders.tuple(Encoders.INT(), Encoders.STRING()).schema());

        df.sort(functions.asc("id")).show();
    }
}

output:

+---+-------+
| id|  fruit|
+---+-------+
|  1|  apple|
|  2|  lemon|
|  3| banana|
+---+-------+

asc_nulls_first() – ascending with nulls first

Similar to asc function but null values return first and then non-null values.

Example in Java:

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.functions;

import java.util.Arrays;

public class SortFunctions {
    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder()
                .appName("SortFunctionsExample")
                .master("local")
                .getOrCreate();

        Dataset<Row> df = spark.createDataset(Arrays.asList(
                RowFactory.create(null, "kiwi"),
                RowFactory.create(3, "banana"),
                RowFactory.create(2, "lemon")
        ), Encoders.tuple(Encoders.INTEGER(), Encoders.STRING()).schema());

        df.sort(functions.asc_nulls_first("id")).show();
    }
}

output:

+----+-------+
|  id|  fruit|
+----+-------+
|null|   kiwi|
|   2|  lemon|
|   3| banana|
+----+-------+

asc_nulls_last()  – ascending with nulls last

Similar to asc function but non-null values return first and then null values.

Example in Java:

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.functions;

import java.util.Arrays;

public class SortFunctions {
    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder()
                .appName("SortFunctionsExample")
                .master("local")
                .getOrCreate();

        Dataset<Row> df = spark.createDataset(Arrays.asList(
                RowFactory.create(null, "kiwi"),
                RowFactory.create(3, "banana"),
                RowFactory.create(2, "lemon")
        ), Encoders.tuple(Encoders.INTEGER(), Encoders.STRING()).schema());

        df.sort(functions.asc_nulls_last("id")).show();
    }
}

output:

+----+-------+
|  id|  fruit|
+----+-------+
|   2|  lemon|
|   3| banana|
|null|   kiwi|
+----+-------+

desc() – descending function

desc function is used to specify the descending order of the DataFrame or DataSet sorting column.

Example in Java:

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.functions;

import java.util.Arrays;

public class SortFunctions {
    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder()
                .appName("SortFunctionsExample")
                .master("local")
                .getOrCreate();

        Dataset<Row> df = spark.createDataset(Arrays.asList(
                RowFactory.create(1, "apple"),
                RowFactory.create(3, "banana"),
                RowFactory.create(2, "lemon")
        ), Encoders.tuple(Encoders.INT(), Encoders.STRING()).schema());

        df.sort(functions.desc("id")).show();
    }
}

output:

+---+-------+
| id|  fruit|
+---+-------+
|  3| banana|
|  2|  lemon|
|  1|  apple|
+---+-------+

desc_nulls_first() – descending with nulls first

Similar to desc function but null values return first and then non-null values.

Example in Java:

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.functions;

import java.util.Arrays;

public class SortFunctions {
    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder()
                .appName("SortFunctionsExample")
                .master("local")
                .getOrCreate();

        Dataset<Row> df = spark.createDataset(Arrays.asList(
                RowFactory.create(null, "kiwi"),
                RowFactory.create(3, "banana"),
                RowFactory.create(2, "lemon")
        ), Encoders.tuple(Encoders.INTEGER(), Encoders.STRING()).schema());

        df.sort(functions.desc_nulls_first("id")).show();
    }
}

output:

+----+-------+
|  id|  fruit|
+----+-------+
|null|   kiwi|
|   3| banana|
|   2|  lemon|
+----+-------+

desc_nulls_last() – descending with nulls last

Similar to desc function but non-null values return first and then null values.

Example in Java:

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.sql.functions;

import java.util.Arrays;

public class SortFunctions {
    public static void main(String[] args) {
        SparkSession spark = SparkSession.builder()
                .appName("SortFunctionsExample")
                .master("local")
                .getOrCreate();

        Dataset<Row> df = spark.createDataset(Arrays.asList(
                RowFactory.create(null, "kiwi"),
                RowFactory.create(3, "banana"),
                RowFactory.create(2, "lemon")
        ), Encoders.tuple(Encoders.INTEGER(), Encoders.STRING()).schema());

        df.sort(functions.desc_nulls_last("id")).show();
    }
}

output:

+----+-------+
|  id|  fruit|
+----+-------+
|   3| banana|
|   2|  lemon|
|null|   kiwi|
+----+-------+