在图表统计时,经常会有要按日期去统计数据的情况,如统计每日的点击量,使用量,查看量等数据,通过查看一段时间内的连续数据来感知指标的趋势变化。
这图表的数据需要每天的数据,即使当天没有数据也要能汇总结果0.
以下示例基于示例的用户表:
CREATE TABLE `user` (
`id` bigint NOT NULL AUTO_INCREMENT,
`created_at` datetime(6) NOT NULL DEFAULT CURRENT_TIMESTAMP(6),
`updated_at` datetime(6) NOT NULL DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6),
`username` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '用户名称',
`email` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '邮箱',
`phone` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '电话',
`password` varchar(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '密码',
`is_active` tinyint(1) NOT NULL DEFAULT 1 COMMENT '是否激活',
`last_login` datetime(6) NULL DEFAULT NULL COMMENT '最后登录时间'
)
name | type | Description |
---|---|---|
id | bigint | id |
created_at | datetime | |
updated_at | datetime | |
username | varchar | 用户名称 |
varchar | 邮箱 | |
phone | varchar | 电话 |
password | varchar | 密码 |
is_active | tinyint | 是否激活 |
last_login | datetime | 最后登录时间 |
Mysql 8 中增加了一个新特性 CTE(Common Table Expressions)通用表表达式,是一种命名的临时结果集,它只存在于单个 SQL 语句的执行范围内。你可以把它想象成一个临时视图,只在当前查询中有效。CTE 主要用于简化复杂的查询,提高可读性和可维护性。
CTE 使用 WITH 语句定义,其基本语法如下:
-- WITH: 声明 CTE 的关键字。
-- cte_name: CTE 的名称,必须符合 MySQL 的标识符命名规则。
-- AS: 关键字,用于将 CTE 的定义与名称关联起来。
-- SELECT ... FROM ... WHERE ...: 定义 CTE 的查询语句。这个查询语句的结果将被存储在 CTE 中。
-- SELECT ... FROM cte_name: 使用 CTE 的查询语句。这个语句可以从 CTE 中选择数据。
WITH cte_name AS (
SELECT ... FROM ... WHERE ...
)
SELECT ... FROM cte_name;
-- 可以在一个 WITH 语句中定义多个 CTE,用逗号分隔:
WITH cte1 AS (
SELECT ...
),
cte2 AS (
SELECT ... FROM cte1
)
SELECT ... FROM cte2;
使用CTE获取每日注册用户量
WITH daily_registrations AS (
SELECT
DATE(created_at) AS register_date, -- 按日期截取(去除时间部分)
COUNT(*) AS registration_count -- 统计当天注册用户数
FROM user
WHERE created_at IS NOT NULL
GROUP BY DATE(created_at)
)
SELECT
register_date,
registration_count
FROM daily_registrations
ORDER BY register_date DESC;
-- daily_registrations 生成了个临时结果集给后续的查询使用,仅用来展示CTE的使用
使用CTE获取每日注册用户量
-- 统计区间内注册
-- 设置变量(实际使用中可替换为传参,如存储过程或应用层参数)
-- SET @start_date = '2025-04-01';
-- SET @end_date = '2025-04-10';
-- WITH RECURSIVE date_series AS (
-- -- 锚点:从指定开始日期出发
-- SELECT @start_date AS date
-- UNION ALL
-- -- 递归:逐日递增,直到结束日期
-- SELECT date + INTERVAL 1 DAY
-- FROM date_series
-- WHERE date = d.date
AND u.created_at
注:created_at
上建立了索引, 则避免在索引列上使用函数,否则索引会失效
数据库必须对 每一行的 created_at
值计算 DATE()
,然后比较
即使 created_at
有索引,也无法直接使用索引查找
因为索引存储的是原始 datetime
值(如 '2025-04-05 10:30:00')
而不是 DATE()
计算后的结果('2025-04-05')
数据量大且查询频繁时:
LEFT JOIN … ON u.created_at >= d.date AND u.created_at 仍会导致范围查找,如果只关心“天”而不关心时分秒,可额外冗余一个 created_date DATE 字段并建索引,可改成 ON u.created_date = d.date。
1)一次性建表(只需执行一次)
CREATE TABLE dim_calendar (
day DATE PRIMARY KEY
);
-- 生成 2020-01-01 ~ 2030-12-31 共 4018 行
INSERT INTO dim_calendar (day)
SELECT DATE_ADD('2020-01-01', INTERVAL seq DAY)
FROM (
SELECT a.N + b.N * 10 + c.N * 100 + d.N * 1000 AS seq
FROM
(SELECT 0 AS N UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) a,
(SELECT 0 AS N UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) b,
(SELECT 0 AS N UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) c,
(SELECT 0 AS N UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) d
) t
WHERE seq
2)按日期统计(查询)
SELECT
c.day AS reg_date,
COALESCE(COUNT(u.id), 0) AS reg_cnt
FROM dim_calendar c
LEFT JOIN `user` u
ON DATE(u.created_at) = c.day
WHERE c.day BETWEEN DATE_SUB(CURDATE(), INTERVAL 29 DAY) AND CURDATE()
GROUP BY c.day
ORDER BY c.day;
1)一次性建表
CREATE TABLE numbers (n TINYINT PRIMARY KEY);
INSERT INTO numbers (n)
SELECT a.N + b.N * 10 AS n
FROM
(SELECT 0 N UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION
SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) a,
(SELECT 0 N UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION
SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) b;
2)按日期统计(查询)100天以内,要更多可创建更大的辅助表
SET @start_date := '2024-03-01';
SET @end_date := '2024-03-31';
SELECT
d.reg_date,
COUNT(u.id) AS reg_cnt
FROM (
SELECT DATE_ADD(@start_date, INTERVAL n DAY) AS reg_date
FROM numbers
WHERE n BETWEEN 0 AND DATEDIFF(@end_date, @start_date)
) d
LEFT JOIN `user` u ON u.created_at >= d.reg_date
AND u.created_at
优点:
echarts 配置
// 模拟接口数据返回
const userLoginArray = [
{ date: '2025-07-01', count: 10 },
{ date: '2025-07-02', count: 0 },
{ date: '2025-07-03', count: 5 },
{ date: '2025-07-04', count: 1 },
{ date: '2025-07-05', count: 8 },
{ date: '2025-07-06', count: 6 }
];
const [categoryDate, dateCount] = userLoginArray.reduce(
([dates, counts], { date, count }) => [
[...dates, date],
[...counts, count]
],
[[], []]
);
option = {
xAxis: { type: 'category', data: categoryDate },
yAxis: { type: 'value'},
series: [
{ type: 'bar', data: dateCount}
]
};
echarts dateset 格式配置
const userLoginArray = [
{date: '2025-07-01', count: 10 },
{date: '2025-07-02', count: 0 },
{date: '2025-07-03', count: 5 },
{date: '2025-07-04', count: 1 },
{date: '2025-07-05', count: 8 },
{date: '2025-07-06', count: 6 },
]
option = {
dataset: {
dimensions: ['date', 'count'],
source: userLoginArray,
},
xAxis: { type: 'category' },
yAxis: { type: 'value'},
series: [{ type: 'bar'}]
};
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