Question

我有一个名为Order的表

   OrderID        CustomerID        IsPaid  
--------------------------------------------
    1              12                 no      
    2              12                 yes
    3              13                 no      
    4              13                 no
    5              14                 yes      
    6              14                 yes

我有一个名为Customer

的表

   CustomerID      Cust_name    
--------------------------------
    12              John                       
    13              Nick                 
    14              Paul

我需要分散那些已经为订单付款但尚未为之前的订单付款的客户，所以结果应该是

   CustomerID      Cust_name    
--------------------------------
    12              John

Answer 1

您可以进行聚合：

select c.CustomerID, c.Cust_name
from Customer c inner join
     Order o
     on o.CustomerID = c.CustomerID
group by c.CustomerID, c.Cust_name   
having min(o.IsPaid) <> max(o.IsPaid);

Answer 2

这样，您将仅在存在的情况下获取输出

SELECT *
FROM   customer
       INNER JOIN order
               ON customer.customerid = order.customerid
WHERE  ispaid = 'yes';

Answer 3

您可以尝试以下方法：

SELECT   DISTINCT
         cust.CustomerID,
         cust.Cust_name
FROM     customer cust
JOIN     order    paid
  ON     cust.CustomerID = paid.CustomerID
 AND     paid.IsPaid = 'yes'
JOIN     order    unpd
  ON     cust.CustomerID = unpd.CustomerID
 AND     unpd.IsPaid = 'no'
 AND     unpd.OrderID < paid.OrderID
ORDER BY cust.CustomerID,
         cust.Cust_name;

执行以下操作可能会更便宜：

SELECT   DISTINCT
         cust.CustomerID,
         cust.Cust_name
FROM     customer cust
JOIN     order    paid
  ON     cust.CustomerID = paid.CustomerID
 AND     paid.IsPaid = 'yes'
WHERE    EXISTS (SELECT *
                 FROM   order unpd
                 WHERE  cust.CustomerID = unpd.CustomerID
                   AND  unpd.IsPaid = 'no'
                   AND  unpd.OrderID < paid.OrderID)
ORDER BY cust.CustomerID,
         cust.Cust_name;

Answer 4

由于您的问题明确指出“未为之前的订单付款”，因此窗口功能应该是您的首选！

SELECT *
FROM
(
    SELECT *,
           LAG(IsPaid) OVER (PARTITION BY CustomerID ORDER BY OrderId) AS IsPreviousOrderPaid
    FROM #Orders AS o
) ordersWithPrevious
    INNER JOIN #Customer AS c
        ON c.CustomerId = ordersWithPrevious.CustomerID
WHERE ordersWithPrevious.IsPaid = 1
      AND ordersWithPrevious.IsPreviousOrderPaid = 0;

Answer 5

您可以做这样的事情。

{
"_id" : "i34908s",
"lifeStageCourses" : [ 
    {
        "lifeStage" : "in_school",
        "tags" : [ 
            "IIT-182"

        ],
        "courseIds" : []
    }, 
    {
        "lifeStage" : "in_college",
        "tags" : [ 
            "IIT-134", 
            "IIT-140",
            "IIT-395"
        ],
        "courseIds" : []
    }, 
    {
        "lifeStage" : "prep_entrance_exam",
        "tags" : [],
        "courseIds" : []
    }, 
    {
        "lifeStage" : "job_seeker",
        "tags" : [ 
            "IIT-134",
            "IIT-395"
        ],
        "courseIds" : []
    }
]
}

在线演示：Link

表结构和样本数据

SELECT t1.customerid,
       Max(cust_name) AS cust_name
FROM   table1 t1
       INNER JOIN table2 t2 using (customerid)
GROUP  BY t1.customerid
HAVING Group_concat(ispaid) = "no,yes"

如何比较下一行的值？

5 个答案: