MySql对同一列进行多次计数

使用指定的WHERE子句作为CASE语句，将计数更改为SUM，true值为1，false值为0

差不多

10 Days    20 Days    100 Days

350        280        90

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如图所示，需要使用相同的表左键连接，感谢此操作成功，但没有和w.invoiceDate10 Days 20 Days 100 Days 350 280 90

SELECT  SUM( CASE WHEN w.invoiceDate < DATE_SUB(curdate(), INTERVAL 10 DAY) THEN 1 ELSE 0 END) AS '10 Days',
        SUM( CASE WHEN w.invoiceDate < DATE_SUB(curdate(), INTERVAL 20 DAY) THEN 1 ELSE 0 END) AS '20 Days'
FROM    tbl_Invoice w 
WHERE   w.invoiceId NOT IN( 
                            SELECT  inv.invoiceId 
                            FROM    tbl_InvoiceAllocation inv) 
AND     w.invoiceDate < DATE_SUB(curdate(), INTERVAL 20 DAY)