Clickhouse 数组函数使用总结—— Clickhouse 基础篇（六）

文章目录

判断空数组

sql 复制代码

SELECT empty([]) AS a, empty([1]) AS b, empty('') AS c;

###################
┌─a─┬─b─┬─c─┐
│ 1 │ 0 │ 1 │
└───┴───┴───┘

判断非空数组

sql 复制代码

SELECT notEmpty([]) AS a, notEmpty([1]) AS b, notEmpty('') AS c;

###################
┌─a─┬─b─┬─c─┐
│ 0 │ 1 │ 0 │
└───┴───┴───┘

计算长度

sql 复制代码

SELECT
    '' AS a,
    [] AS b,
    [1] AS c,
    length(a) AS length_a,
    length(b) AS length_b,
    length(c) AS length_c

Query id: 6a6ee36e-a60f-482c-a6a9-1566d91947ae

┌─a─┬─b──┬─c───┬─length_a─┬─length_b─┬─length_c─┐
│   │ [] │ [1] │        0 │        0 │        1 │
└───┴────┴─────┴──────────┴──────────┴──────────┘

根据范围构造数组

range([start,] end [, step])

sql 复制代码

SELECT
    range(10) AS a,
    range(1, 10) AS b,
    range(1, 10, 2) AS c

Query id: 97016df3-93c5-4d5c-8057-b0d3607f31b0

┌─a─────────────────────┬─b───────────────────┬─c───────────┐
│ [0,1,2,3,4,5,6,7,8,9] │ [1,2,3,4,5,6,7,8,9] │ [1,3,5,7,9] │
└───────────────────────┴─────────────────────┴─────────────┘

拼接数组

sql 复制代码

SELECT arrayConcat([1, 2], [3, 4], [5, 6]) AS res

Query id: ca8de8f4-6eae-429d-bbf6-304535061da8

┌─res───────────┐
│ [1,2,3,4,5,6] │
└───────────────┘

根据下标查询数组元素

sql 复制代码

SELECT
    [1, 2, 3, 4, 5] AS arr,
    arr[1] AS a1,
    arr[2] AS a2

Query id: 3d867603-003f-43cf-8471-d69d077fa844

┌─arr─────────┬─a1─┬─a2─┐
│ [1,2,3,4,5] │  1 │  2 │
└─────────────┴────┴────┘

判断是否包含元素

sql 复制代码

SELECT
    [1, 2, 3, 4, 5] AS arr,
    3 AS x,
    has(arr, x) AS res

Query id: 0f7467ec-d004-4ce8-ae15-3c8422445308

┌─arr─────────┬─x─┬─res─┐
│ [1,2,3,4,5] │ 3 │   1 │
└─────────────┴───┴─────┘

判断是不是子数组

sql 复制代码

SELECT
    [1, 2, 3, 4, 5] AS set,
    [1, 3] AS subset,
    hasAll(set, subset) AS res

Query id: 93f55924-4bba-4abd-a6c7-8665d9768cf4

┌─set─────────┬─subset─┬─res─┐
│ [1,2,3,4,5] │ [1,3]  │   1 │
└─────────────┴────────┴─────┘

判断两个数组是否有交集

sql 复制代码

SELECT
    [1, 2, 3, 4, 5] AS set,
    [1, 3] AS subset,
    [8, 9] AS y,
    hasAny(set, subset) AS res1,
    hasAny(set, y) AS res2

Query id: c9bbe03a-bf3f-461c-818c-e1ee470b5555

┌─set─────────┬─subset─┬─y─────┬─res1─┬─res2─┐
│ [1,2,3,4,5] │ [1,3]  │ [8,9] │    1 │    0 │
└─────────────┴────────┴───────┴──────┴──────┘

返回元素下标

sql 复制代码

SELECT
    [1, 2, 3, 4, 5] AS arr,
    3 AS x,
    indexOf(arr, x) AS res

Query id: 96eceb10-b58b-41ff-acf2-0cfef5e90ccb

┌─arr─────────┬─x─┬─res─┐
│ [1,2,3,4,5] │ 3 │   3 │
└─────────────┴───┴─────┘

数组切片

sql 复制代码

SELECT arraySlice([1, 2, 3, 4, 5], 2, 3) AS res

Query id: b4764de1-e2b3-4624-aa68-34eca492037a

┌─res─────┐
│ [2,3,4] │
└─────────┘

数组升序排序

sql 复制代码

SELECT arraySort([1, 3, 2, 5, 7, 6, 0]) AS res

Query id: 8fd0be21-4d18-448e-8aea-70389e66147b

┌─res─────────────┐
│ [0,1,2,3,5,6,7] │
└─────────────────┘

数组降序排序

sql 复制代码

SELECT arrayReverseSort([1, 3, 2, 5, 7, 6, 0]) AS res

Query id: d920f5f6-75d4-430b-af86-877f847a1525

┌─res─────────────┐
│ [7,6,5,3,2,1,0] │
└─────────────────┘

数组自定义排序

使用 lambda 表达式

sql 复制代码

SELECT arraySort(x -> (-x), [1, 2, 3]) AS res

Query id: eca589b4-83aa-4264-963c-bbb088a1ae43

┌─res─────┐
│ [3,2,1] │
└─────────┘

计算数组不重复元素个数

sql 复制代码

SELECT arrayUniq([1, 2, 2, 3, 4, 5, 5]) AS res

Query id: d313e61d-8fc1-4931-93c0-f76e447c5273

┌─res─┐
│   5 │
└─────┘

数组元素去重

sql 复制代码

SELECT arrayDistinct([1, 2, 2, 3, 4, 5, 5, 6, 6, 6]) AS res

Query id: 51b5abac-379a-47d1-ae0f-f7b826be8834

┌─res───────────┐
│ [1,2,3,4,5,6] │
└───────────────┘

数组交集

sql 复制代码

SELECT
    arrayIntersect([1, 2], [3, 4], [2, 3]) AS no_interset,
    arrayIntersect([1, 2, 5], [1, 2, 3], [1, 2, 4]) AS interset

Query id: 4886d4de-8d56-4a1f-8694-f6ad9896f323

┌─no_interset─┬─interset─┐
│ []          │ [2,1]    │
└─────────────┴──────────┘

数组归并

将聚合函数应用于数组元素并返回其结果，函数以单引号括起来

sql 复制代码

SELECT arrayReduce('uniq', [1, 2, 3, 4, 5, 5, 5, 6, 6]) AS res

Query id: df912733-1914-4ffb-b1e8-e112b1157b29

┌─res─┐
│   6 │
└─────┘

数组逆序

sql 复制代码

SELECT arrayReverse([1, 2, 3]) AS res

Query id: d0f8bfaf-441e-4cc9-abec-af3b3473a9b1

┌─res─────┐
│ [3,2,1] │
└─────────┘

数组拍平

sql 复制代码

SELECT flatten([[1, 2, 3], [2, 3, 4], [3, 4, 5]]) AS res

Query id: f42113b9-7500-4242-a7b8-937f8d53924a

┌─res─────────────────┐
│ [1,2,3,2,3,4,3,4,5] │

数组压缩成一个元组数组

sql 复制代码

SELECT arrayZip(['a', 'b', 'c'], [3, 2, 1]) AS res

Query id: 8ad7b1d6-fb23-4a5c-bb61-0a78c1b76d7f

┌─res───────────────────────┐
│ [('a',3),('b',2),('c',1)] │
└───────────────────────────┘

数组元素映射

sql 复制代码

SELECT arrayMap(x -> (x * x), [1, 2, 3]) AS res

Query id: aa12c467-7fb9-4314-b052-a647d6fb8efd

┌─res─────┐
│ [1,4,9] │
└─────────┘

数组过滤

sql 复制代码

SELECT
    [1, 2, 3, 4, 5, 6, 7, 8, 9] AS arr,
    arrayFilter(x -> ((x % 2) = 0), arr) AS res

Query id: 358b9dec-cc62-4a45-a4e5-1e982a3cb5a4

┌─arr─────────────────┬─res───────┐
│ [1,2,3,4,5,6,7,8,9] │ [2,4,6,8] │
└─────────────────────┴───────────┘

求数组最小元素

sql 复制代码

SELECT arrayMin([1, 2, 3]) AS res

Query id: f21443b5-b195-4f46-ab1b-dd16bfe4e99a

┌─res─┐
│   1 │
└─────┘

求数组最大元素

sql 复制代码

SELECT arrayMax([1, 2, 3]) AS res

Query id: f21443b5-b195-4f46-ab1b-dd16bfe4e99a

┌─res─┐
│   3 │
└─────┘

数组元素求和

sql 复制代码

SELECT arraySum([1, 2, 3]) AS res

Query id: b5bbd5f6-0c68-4327-a7f3-524eff944537

┌─res─┐
│   6 │
└─────┘

数组元素平均值

sql 复制代码

SELECT arrayAvg([1, 2, 3, 4]) AS res

Query id: 8c77fc4f-cbf7-4f8b-a1c8-89a895a8578f

┌─res─┐
│ 2.5 │
└─────┘

数组元素相乘

sql 复制代码

SELECT arrayProduct([1, 2, 3, 4, 5]) AS res

Query id: 69507cdf-1d99-4e4d-b314-feafd705430b

┌─res─┐
│ 120 │
└─────┘

数组元素展开

sql 复制代码

SELECT
    arrayJoin([1, 2, 3]) AS e,
    'abc' AS a

Query id: e5358a00-b344-4cfd-b3fd-b25bd4e0f39b

┌─e─┬─a───┐
│ 1 │ abc │
│ 2 │ abc │
│ 3 │ abc │
└───┴─────┘