Mysql 如果未找到任何记录，则sql获取零作为值

我有一个简单的问题，我四处看看，但不能让它为我工作。我对当前日期进行了查询，假设明天是星期二，但其中没有数据，因为这是未来。而且里面还没有记录

当我运行查询时，它只显示2个列，称为

total | Date

它照我说的做。但是现在我想让它显示

0

，而不是只显示2列

我确实搜索了COALESCE，但由于某种原因，它不起作用，也没有给我任何错误

SELECT
    SUM(totalExcl) AS total, 
    DATE_FORMAT(date_add, '%W') AS 'Date'  
FROM
    ex.ps_ox_quotation 
WHERE 
    WEEK(date_add) = WEEK (UTC_TIMESTAMP()) 
        AND saleType IN ('IEW' , 'A', 'Project')
        AND DAYOFWEEK(date_add) % 6 > 4 
GROUP BY Date 
ORDER BY 'Date' DESC 

我有什么（桌子）=

我想要什么（桌子）=

今天是星期三，所以它是当前日期，这是它显示的（顺便说一句，这是当前日期），我只是显示它：

| |total | Date
    500    Wednesday

---

尝试使用IFNULL

SELECT
    IFNULL(SUM(totalExcl),0) AS total, 
    DATE_FORMAT(date_add, '%W') AS 'Date'  
FROM
    ex.ps_ox_quotation 
WHERE 
    WEEK(date_add) = WEEK (UTC_TIMESTAMP()) 
        AND saleType IN ('IEW' , 'A', 'Project')
        AND DAYOFWEEK(date_add) % 6 > 4 
GROUP BY Date 
ORDER BY 'Date' DESC 

试试这个

SELECT
IF(SUM(totalExcl) is NULL,0,SUM(totalExcl)) AS total, 
DAYNAME(date_add) AS 'Date'  
FROM
ex.ps_ox_quotation 
WHERE 
WEEK(date_add) = WEEK (UTC_TIMESTAMP()) 
    AND saleType IN ('IEW' , 'A', 'Project')
    AND DAYOFWEEK(date_add) % 6 > 4 
GROUP BY Date 
ORDER BY 'Date' DESC 

或者你可以这样做

SELECT
IF(SUM(totalExcl) is NULL,0,SUM(totalExcl)) AS total, 
IF(DATE_FORMAT(date_add, '%W') is null,DAYNAME(now()),DATE_FORMAT(date_add, '%W')) AS 'Date'  
FROM
ex.ps_ox_quotation 
WHERE 
WEEK(date_add) = WEEK (UTC_TIMESTAMP()) 
    AND saleType IN ('IEW' , 'A', 'Project')
    AND DAYOFWEEK(date_add) % 6 > 4 
GROUP BY Date 
ORDER BY 'Date' DESC 

---

我想您需要“`@@ROWCOUNT``谢谢，我会尽快尝试。尝试后请告诉我。第一个可行，但在列日期给我一个空值。第二个也做了这项工作，并没有给我null，而是给了我列Date的实际日期名称。对于这两种情况，如果还没有记录的话，它给了我一个零（o）的列总数，所以它完成了任务。非常感谢。

SELECT
IF(SUM(totalExcl) is NULL,0,SUM(totalExcl)) AS total, 
DAYNAME(date_add) AS 'Date'  
FROM
ex.ps_ox_quotation 
WHERE 
WEEK(date_add) = WEEK (UTC_TIMESTAMP()) 
    AND saleType IN ('IEW' , 'A', 'Project')
    AND DAYOFWEEK(date_add) % 6 > 4 
GROUP BY Date 
ORDER BY 'Date' DESC 

SELECT
IF(SUM(totalExcl) is NULL,0,SUM(totalExcl)) AS total, 
IF(DATE_FORMAT(date_add, '%W') is null,DAYNAME(now()),DATE_FORMAT(date_add, '%W')) AS 'Date'  
FROM
ex.ps_ox_quotation 
WHERE 
WEEK(date_add) = WEEK (UTC_TIMESTAMP()) 
    AND saleType IN ('IEW' , 'A', 'Project')
    AND DAYOFWEEK(date_add) % 6 > 4 
GROUP BY Date 
ORDER BY 'Date' DESC