MYSQL 语法帮助答案

【问题标题】：MYSQL Syntax AssistanceMYSQL 语法帮助
【发布时间】：2021-06-10 20:12:57
【问题描述】：

有人可以用这个查询为我指明正确的方向吗？无论我尝试哪种方式，我都会继续出错

SELECT b.SOLD_TO
     , b.CUSTOMER
     , b.JANUARY_BUDGET
     , Round(sum(d.TOTAL_WEIGHT)/1000,2) AS MONTHLY_DESPATCH
     , if(sum(d.TOTAL_WEIGHT)/1000=0 AND b.JANUARY_BUDGET=0,"DOUBLE_ZERO",
if(sum(d.TOTAL_WEIGHT)/1000>0 AND b.JANUARY_BUDGET=0,"NO_BUDGET_GOOD_SHIPMENT",
if(sum(d.TOTAL_WEIGHT)/1000>0 AND b.JANUARY_BUDGET>0 AND (sum(d.TOTAL_WEIGHT)/1000> b.JANUARY_BUDGET,"ABOVE_BUDGET",
if(sum(d.TOTAL_WEIGHT)/1000>0 AND b.JANUARY_BUDGET>0 AND (sum(d.TOTAL_WEIGHT)/1000< b.JANUARY_BUDGET,"POOR_RESULT")))) AS PERFORMANCE
FROM budget2021 b
left JOIN despatches2021 d on d.SOLD_TO = b.SOLD_TO
WHERE b.SOLD_TO=69946 AND d.INVOICE_DATE BETWEEN 20210101 and 20210131
GROUP BY b.SOLD_TO
     , b.CUSTOMER
     , b.JANUARY_BUDGET

【问题讨论】：

等到您了解表别名。他们会让你大吃一惊:-)。并且知道LEFT JOIN x ... WHERE x =... 与INNER JOIN x... 相同
@RocketHazmat 好建议，谢谢。我将数据放入 php 并根据 mysql 发送给它的数据将其处理为 4 个查询。愚蠢的为什么我以前没有想到这个，一个更简单的解决方案！再次感谢
删除所有/1000。如果一个数除以 1000 是正数，那么这个数本身也是正数。
请解释“无论我尝试哪种方式”以及“我遇到错误”。究竟是什么错误？你试过什么？
首先，没有右括号，然后从那里走下坡路： if(sum(d.TOTAL_WEIGHT)/1000=0 AND b.JANUARY_BUDGET=0,"DOUBLE_ZERO "

标签： mysql syntax syntax-error

【解决方案1】：

嗯，很难解释，你做错了什么

IF(condition,true,false) 是独立于嵌套数量的形式。

上帝的代码缩进有助于处理这些事情

我还必须在最后一个 IF 的末尾添加一个 NULL，因为我真的不知道你想用这个去哪里

SELECT 
    b.SOLD_TO,
    b.CUSTOMER,
    b.JANUARY_BUDGET,
    ROUND(SUM(d.TOTAL_WEIGHT) / 1000, 2) AS MONTHLY_DESPATCH,
    IF(SUM(d.TOTAL_WEIGHT) / 1000 = 0
            AND b.JANUARY_BUDGET = 0,
        'DOUBLE_ZERO',
        IF(SUM(d.TOTAL_WEIGHT) / 1000 > 0
                AND b.JANUARY_BUDGET = 0,
            'NO_BUDGET_GOOD_SHIPMENT',
            IF(SUM(d.TOTAL_WEIGHT) / 1000 > 0
                    AND b.JANUARY_BUDGET > 0
                    AND (SUM(d.TOTAL_WEIGHT) / 1000 > b.JANUARY_BUDGET),
                'ABOVE_BUDGET',
                IF(SUM(d.TOTAL_WEIGHT) / 1000 > 0
                        AND b.JANUARY_BUDGET > 0
                        AND (SUM(d.TOTAL_WEIGHT) / 1000 < b.JANUARY_BUDGET),
                    'POOR_RESULT',
                    NULL)))) AS PERFORMANCE   -- here i added the NULL
FROM
    budget2021 b
        LEFT JOIN
    despatches2021 d ON d.SOLD_TO = b.SOLD_TO
WHERE
    b.SOLD_TO = 69946
        AND d.INVOICE_DATE BETWEEN 20210101 AND 20210131
GROUP BY b.SOLD_TO , b.CUSTOMER , b.JANUARY_BUDGET

【讨论】：

惊人的工作！它适用于每种组合。 '双零不会产生任何记录，但我可以将其用作“空”，非常感谢
感谢大家，我对这个论坛的帮助（和专业知识）感到震惊，感谢所有做出贡献的人
那个 LEFT JOIN 仍然没有做太多的事情