PHP Mysql 选择查询来排序对

Question

我正在为舞蹈学校制作客户数据库应用程序。

我需要显示参与同一舞蹈级别的所有客户的概览。但我想要的是情侣的概览订单，而不是客户 ID 的订单。 为此，我要连接三个表(请查看下面的查询) 每个客户在 CRM_CONTACTS 表中都有一个唯一的 ID，并且在该行中还有对其合作伙伴 (PARTNER_ID) 的引用。

表 CRM_CONTACTS

ID   CONTACTS_LNAME
1    VON KLOMPENBURG
2    Mc Donalds
3    MC Adams
4    Mr X

然后我就有了 CRM_PRODUCTS ID PRODUCTS_NAME
1 初学者 2 中间体 3进阶

然后是我为联系人分配产品/级别并指出他/她的合作伙伴的表格

ID   CONTACTS_ID    PRODUCTS_ID   PARTNER_ID
1    1              1             4
2    2              1             3
3    3              1             2
4    4              1             1

现在我想收到基于parter_id的情侣列表订单 所以对于初学者水平我会得到这样的列表 1 冯·克隆彭堡 2 X先生 3 麦当劳 4 麦克亚当斯

这是我的选择语句

 $result = mysqli_query($coni,"SELECT CRM_PRODUCTS_PURCHASE.ID, CONTACTS_ID, 
CRM_PRODUCTS.PRODUCTS_NAME, 
CRM_PRODUCTS.PRODUCTS_PRICE,CRM_PRODUCTS_PURCHASE.PARTNER_ID, 
CRM_PRODUCTS_PURCHASE.PARTNER_NAME, 
PRODUCTS_PURCHASE_REMARKS,PRODUCTS_PURCHASE_DISCOUNT, 
PRODUCTS_PURCHASE_PAIDBYBANK,PRODUCTS_PURCHASE_PAIDBYCASH, 
CRM_CONTACTS.CONTACTS_LNAME, CRM_CONTACTS.CONTACTS_FNAME 
FROM CRM_PRODUCTS_PURCHASE
LEFT JOIN CRM_CONTACTS ON CRM_PRODUCTS_PURCHASE.CONTACTS_ID = CRM_CONTACTS.ID 
LEFT JOIN CRM_PRODUCTS ON CRM_PRODUCTS_PURCHASE.PRODUCTS_ID = CRM_PRODUCTS.ID
WHERE CRM_PRODUCTS_PURCHASE.PRODUCTS_ID = '". $PRODUCTS_ID . "'");

Answer 1

你可以这样做:

$result = mysqli_query($coni,"SELECT CRM_PRODUCTS_PURCHASE.ID, CONTACTS_ID, 
CRM_PRODUCTS.PRODUCTS_NAME, 
CRM_PRODUCTS.PRODUCTS_PRICE,CRM_PRODUCTS_PURCHASE.PARTNER_ID, 
CRM_PRODUCTS_PURCHASE.PARTNER_NAME, 
PRODUCTS_PURCHASE_REMARKS,PRODUCTS_PURCHASE_DISCOUNT, 
PRODUCTS_PURCHASE_PAIDBYBANK,PRODUCTS_PURCHASE_PAIDBYCASH, 

CRM_CONTACTS.CONTACTS_LNAME, CRM_CONTACTS.CONTACTS_FNAME 
FROM CRM_PRODUCTS_PURCHASE
LEFT JOIN CRM_CONTACTS ON CRM_PRODUCTS_PURCHASE.CONTACTS_ID = CRM_CONTACTS.ID 
LEFT JOIN CRM_PRODUCTS ON CRM_PRODUCTS_PURCHASE.PRODUCTS_ID = CRM_PRODUCTS.ID
WHERE CRM_PRODUCTS_PURCHASE.PRODUCTS_ID = '". $PRODUCTS_ID . "'
ORDER BY IF (ID < PARTNER_ID, ID, PARTNER_ID)");

您的顾客将成对订购。