MySql中按时间分组计数

我有一个简单的查询，可以提供应用程序类型的计数；它看起来像这样：

SELECT Application_Type, COUNT(*) FROM Loan_Applications GROUP BY Application_Type;

Home 3
Car  21
Commercial 16

它返回如下内容：

SELECT Application_Type, COUNT(*) FROM Loan_Applications GROUP BY Application_Type;

Home 3
Car  21
Commercial 16

数据库中有一个名为“提交日期”的字段（日期类型）

如何按周查询和分解这些数据

Type This week   Last week  2 weeks ago
Home    1            1          1
Car     9            6          6 
Commercial 10        0          3

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您可以进行SUMIF类型的计算。以下汇总了提交日期在上周内的行数

SUM(CASE WHEN submission_date >= CURDATE() - 7 THEN 1 ELSE 0 END)

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然后，您可以在不同的范围内重复此操作，以获得您想要的任何“波段”。

您可以尝试以下方法：

SELECT
    Application_Type,
    SUM(IF(Submission_Date BETWEEN CURRENT_DATE AND CURRENT_DATE - INTERVAL 1 WEEK, 1, 0)) AS 'This week',
    SUM(IF(Submission_Date BETWEEN CURRENT_DATE- INTERVAL 1 WEEK AND CURRENT_DATE - INTERVAL 2 WEEK, 1, 0)) AS 'Last week',
    SUM(IF(Submission_Date BETWEEN CURRENT_DATE- INTERVAL 2 WEEK AND CURRENT_DATE - INTERVAL 3 WEEK, 1, 0)) AS '2 weeks ago',
FROM Loan_Applications
GROUP BY Application_Type
;

或：

试一试

它基于这样一个事实，即group by中的布尔表达式的和将在表达式为真时计数