org.apache.flink.table.runtime.operators.rank

枚举 RankType

java.lang.Object

java.lang.Enum<RankType>

org.apache.flink.table.runtime.operators.rank.RankType

所有已实现的接口:

Serializable, Comparable<RankType>

public enum RankType
extends Enum<RankType>

An enumeration of rank type, usable to show how exactly generate rank number.

枚举常量概要

枚举常量

枚举常量和说明
DENSE_RANK is similar to the RANK by generating a unique rank number for each distinct row within the partition based on the order, starting at 1 for the first row in each partition, ranking the rows with equal values with the same rank number, except that it does not skip any rank, leaving no gaps between the ranks.
RANK Returns a unique rank number for each distinct row within the partition based on the order, starting at 1 for the first row in each partition, with the same rank for duplicate values and leaving gaps between the ranks; this gap appears in the sequence after the duplicate values.
ROW_NUMBER Returns a unique sequential number for each row within the partition based on the order, starting at 1 for the first row in each partition and without repeating or skipping numbers in the ranking result of each partition.

方法概要

限定符和类型	方法和说明
static RankType	valueOf(String name) 返回带有指定名称的该类型的枚举常量。
static RankType[]	values() 按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。

从类继承的方法 java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

从类继承的方法 java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

枚举常量详细资料

ROW_NUMBER

public static final RankType ROW_NUMBER

Returns a unique sequential number for each row within the partition based on the order, starting at 1 for the first row in each partition and without repeating or skipping numbers in the ranking result of each partition. If there are duplicate values within the row set, the ranking numbers will be assigned arbitrarily.

RANK

public static final RankType RANK

Returns a unique rank number for each distinct row within the partition based on the order, starting at 1 for the first row in each partition, with the same rank for duplicate values and leaving gaps between the ranks; this gap appears in the sequence after the duplicate values.

DENSE_RANK

public static final RankType DENSE_RANK

is similar to the RANK by generating a unique rank number for each distinct row within the partition based on the order, starting at 1 for the first row in each partition, ranking the rows with equal values with the same rank number, except that it does not skip any rank, leaving no gaps between the ranks.

方法详细资料

values

public static RankType[] values()

按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。该方法可用于迭代 常量, 如下所示:

for (RankType c : RankType.values())
    System.out.println(c);

返回:

按照声明该枚举类型的常量的顺序返回的包含这些常量的数组

valueOf

public static RankType valueOf(String name)

返回带有指定名称的该类型的枚举常量。 字符串必须与用于声明该类型的枚举常量的 标识符完全匹配。(不允许有多余 的空格字符。)

参数:

name - 要返回的枚举常量的名称。

返回:

返回带有指定名称的枚举常量

抛出:

IllegalArgumentException - 如果该枚举类型没有带有指定名称的常量

NullPointerException - 如果参数为空值