MYSQL - 正确连接我的 3 个表的语法

Question

Edit2：选择分离查询并在数据库输出之外将信息作为一个整体进行整理/处理。以 .CSV 格式将它们取出，然后将它们添加到 Excel 中，我将在其中运行实际数字。

查询1以提取订单和所需信息：

SELECT
shipstation_orders_v2.id AS SSO_id,
shipstation_orders_v2.order_number AS SSO_orderNumber,
shipstation_orders_v2.order_id AS SSO_orderID,
shipstation_orders_v2.storename AS SSO_storeName,
shipstation_orders_v2.order_date AS SSO_orderDate,
shipstation_orders_v2.order_total AS SSO_orderTotal,
shipstation_orders_v2.name AS SSO_name,
shipstation_orders_v2.company AS SSO_company

FROM shipstation_orders_v2

GROUP BY shipstation_orders_v2.id,
     shipstation_orders_v2.order_number,
     shipstation_orders_v2.order_id,
     shipstation_orders_v2.storename,
     shipstation_orders_v2.order_date,
     shipstation_orders_v2.order_total,
     shipstation_orders_v2.name,
     shipstation_orders_v2.company

ORDER BY SSO_orderDate

查询 2 以提取履行和等效信息：

SELECT DISTINCT
shipstation_orders_v2.id AS SSO_id,
shipstation_fulfillments.id AS SSF_id,
shipstation_fulfillments.order_number AS SSF_orderNumber,
shipstation_orders_v2.order_number AS SSO_orderNumber,
shipstation_orders_v2.order_id AS SSO_orderID,
shipstation_orders_v2.storename AS SSO_storeName,
shipstation_orders_v2.order_date AS SSO_orderDate,
shipstation_fulfillments.order_date AS SSF_orderDate,
shipstation_orders_v2.order_total AS SSO_orderTotal,
shipstation_fulfillments.amount_paid AS SSF_amountPaid,
shipstation_orders_v2.name AS SSO_name,
shipstation_orders_v2.company AS SSO_company,
shipstation_fulfillments.name AS SSF_name,
shipstation_fulfillments.company AS SSF_company

FROM shipstation_fulfillments

  INNER JOIN shipstation_orders_v2
  ON shipstation_fulfillments.order_number = 
  shipstation_orders_v2.order_number

WHERE shipstation_fulfillments.order_number = 
shipstation_orders_v2.order_number
  GROUP BY shipstation_orders_v2.id,
     shipstation_fulfillments.id,
     shipstation_fulfillments.order_number,
     shipstation_orders_v2.order_number,
     shipstation_orders_v2.order_id,
     shipstation_orders_v2.storename,
     shipstation_orders_v2.order_date,
     shipstation_fulfillments.order_date,
     shipstation_orders_v2.order_total,
     shipstation_fulfillments.amount_paid,
     shipstation_orders_v2.name,
     shipstation_orders_v2.company,
     shipstation_fulfillments.name,
     shipstation_fulfillments.company

编辑：问题标记为已回答。我想出了另一种方法来做到这一点，但并不那么轻率。支持 DRapp 让我的大脑动起来。

原始代码在文字墙下方

我是一名自学成才的 MySQL 数据库用户。我不会说管理员，因为它只是我。我已经为工作整理了一个小型数据库——大约 60,000 行和最多 51 列分布在三个表中。我在工作中使用它来组织相当不同的销售数据设置并理解它以识别趋势、季节性和所有这些好东西。我主要处理 Shipstation 数据。

我的问题是何时需要介绍第三张表。显然，有两个表只是一个简单的JOIN。我让它工作得很好。我在为第三张表正确设置 JOINs 时遇到了很多麻烦。

我正在尝试将来自两个最内层查询的数据JOIN 到shipstation_orders_v2 和order_keys 到我在第三个表中的shipstation_fulfillments 结果。

对于那些不使用 Shipstation 或不熟悉它的这个元素的人来说，履行与订单属于不同的类别，并且不使用完全相同的数据。这是我将它们粘合在一起的肮脏方式，因此我们有一些关于销售和运输趋势等的体面、可操作的信息。

我正在从shipstation_orders_v2 到order_keys 进行内部查询，作为SELECT DISTINCT 拆分订单总和的一种方式。在构建该子查询之前，我遇到了数据重复问题。使用（现在）子查询和子子查询，消除了重复问题，并且仅使用这两个表就可以正常工作。

问题是，当我将 SELECT 从 shipstation_fulfillments 和 JOIN 到子查询和子子查询时，我遇到了障碍。

我在处理这个查询时遇到了几个错误。按发生和解决的顺序：

Error 2013，在查询期间失去与服务器的连接（这告诉我我正在对三个连接的表进行全表读取，因为它没有事先出错，但我的 rinkadink 设置无法处理它）。我摆脱了那个。

然后，对于未识别的表名 shipstation_fulfillments，出现错误 1051。对我来说，我认为这可能是查询别名的问题。我不确定。

最后，好的 ole Error 1064，在 SELECT shipstation_fulfillments 参数。

作为自学成才，我几乎可以保证我只是在某个地方遗漏了一个语法元素，这对于一个熟练的 MySQL 用户来说是相当明显的。以下是我当前的查询设置。

如果需要任何澄清，请告诉我。

SELECT

`shipstation_fulfillments`.`order_date` AS `orderDate`,
`shipstation_fulfillments`.`order_number` AS `orderNumber`,
(`shipstation_fulfillments`.`amount_paid` + `shipstation_fulfillments`.`tax_paid`) AS "Total Paid",
`shipstation_fulfillments`.`name` AS `name`,
`shipstation_fulfillments`.`company` AS `company`,

FROM
(
    (SELECT
        COUNT(`shipstation_orders_v2`.`order_key`) AS `orderCount`,
        `shipstation_orders_v2`.`key_id` AS `key_id`,
        `shipstation_orders_v2`.`order_number` AS `order_number`,
        MAX(`shipstation_orders_v2`.`order_date`) AS `order_date`,
        `shipstation_orders_v2`.`storename` AS `store`,
        (`shipstation_orders_v2`.`order_total` -     `shipstation_orders_v2`.`shippingPaid`) AS `orderPrice`,
        `shipstation_orders_v2`.`shippingpaid` AS `shippingPaid`,
        SUM(`shipstation_orders_v2`.`shippingpaid`) AS `SUM shippingPaid`,
        `shipstation_orders_v2`.`order_total` AS `orderTotal`,
        SUM(`shipstation_orders_v2`.`order_total`) AS `SUM Total Amount Paid`,
        `shipstation_orders_v2`.`qtyshipped` AS `qtyShipped`,
        SUM(`shipstation_orders_v2`.`qtyshipped`) AS `SUM qtyShipped`,
        `shipstation_orders_v2`.`name` AS `name`,
        `shipstation_orders_v2`.`company` AS `company`

        FROM

            (SELECT DISTINCT
                `order_keys`.`key_id` AS `key_id`,
                `order_keys`.`order_key` AS `order_key`,
                `shipstation_orders_v2`.`order_number` AS `order_number`,
                `shipstation_orders_v2`.`order_id` AS `order_id`,
                `shipstation_orders_v2`.`order_date` AS `order_date`,
                `shipstation_orders_v2`.`storename` AS `storename`,
                `shipstation_orders_v2`.`order_total` AS `order_total`,
                `shipstation_orders_v2`.`qtyshipped` AS `qtyshipped`,
                `shipstation_orders_v2`.`shippingpaid` AS `shippingpaid`,
                `shipstation_orders_v2`.`name` AS `name`,
                `shipstation_orders_v2`.`company` AS `company`
    FROM
        (`shipstation_orders_v2`
    JOIN `order_keys` ON ((`order_keys`.`order_key` = `shipstation_orders_v2`.`order_id`)))) `t`)


JOIN `shipstation_fulfillments`
ON (`shipstation_orders_v2`.`order_number` = `shipstation_fulfillments`.`order_number`)) `w`

Answer 1

作为一对夫妇的注释...至于长表名，没问题，但是您可以使用对它们的别名引用，例如我通过示例所做的...ShipStation_Fulfillments SSF...“SSF”现在是别名更短的输入，但仍然有意义。

当通过“AS”更改查询中的列名时，您只需要就好像您的列名结果会像您在开始时那样更改其原始结果，例如 SSF.order_date AS orderDate 从中删除“_”最后的列名，但也在“Total Paid”中（但我讨厌带有嵌入空格的列名，让用户界面处理标签，但这只是我）。

在输入 table.column（或 alias.column）时，通过 CamelCasing 有助于提高可读性，而在大脑自然分解为我们可读的单词的情况下使用 CamelCasing 更难阅读。

基于查询的其他问题。外部查询部分无法识别来自内部封闭查询的别名，只能识别子选择的别名，就像您使用“t”和“w”别名一样。

接下来，在进行 JOIN 时，我的偏好是按照表在查询中的方式来读取它们，其中列出了左侧的第一个，以及右侧加入的任何内容。
如果从表 A 连接到表 B，则 ON 子句将是 ON A.KeyID = B.KeyID vs B.KeyID = A.KeyID 特别是如果你要多张表... A->B, B->C , C->D

任何带有聚合（sum、avg、count、min、max 等）的查询都必须有一个“GROUP BY”子句来确定每条记录何时应该中断。在您的示例中，我假设原始销售订单中断。

虽然此查询不起作用，但这里是您的查询的清理版本，显示了上面的实现。

SELECT
      SSF.order_date AS OrderDate,
      SSF.order_number AS OrderNumber,
      (SSF.amount_paid + SSF.tax_paid) AS `Total Paid`,
      SSF.name,
      SSF.company
   FROM
      ( SELECT
                SSOv2.key_id,
                SSOv2.order_number,
                SSOv2.storename AS store,
                SSOv2.order_total - SSOv2.shippingPaid AS OrderPrice,
                SSOv2.ShippingPaid,
                SSOv2.order_total AS OrderTotal,
                SSOv2.QtyShipped,
                SSOv2.name,
                SSOv2.company,
                COUNT(SSOv2.order_key) AS orderCount,
                MAX(SSOv2.order_date) AS order_date,
                SUM(SSOv2.shippingpaid) AS `SUM shippingPaid`,
                SUM(SSOv2.order_total) AS `SUM Total Amount Paid`,
                SUM(SSOv2.qtyshipped) AS `SUM qtyShipped`
        FROM
            ( SELECT DISTINCT
                    OK.key_id AS key_id,
                    OK.order_key AS order_key,
                    SSOv2.order_number AS order_number,
                    SSOv2.order_id AS order_id,
                    SSOv2.order_date AS order_date,
                    SSOv2.storename AS storename,
                    SSOv2.order_total AS order_total,
                    SSOv2.qtyshipped AS qtyshipped,
                    SSOv2.shippingpaid AS shippingpaid,
                    SSOv2.name AS name,
                    SSOv2.company AS company
                 FROM
                    shipstation_orders_v2 SSOv2
                       JOIN order_keys 
                          ON SSOv2.order_id = OK.order_key
                       JOIN shipstation_fulfillments SSF
                          ON SSOv2.order_number = SSF.order_number ) t 
      ) w

接下来，在没有看到对解决查询至关重要的实际数据或列出的结构的情况下，我会要求您编辑您现有的帖子。创建一个示例表，列出表、列和示例数据，以便我们可以看到您正在聚合并尝试从查询中获取的内容的基础。特别是显示每个订单和履行可能有多行的位置，以及您期望结果显示的示例答案。