如何在 mysql 加入时检查另一个 table 没有数据？

Question

我有两个mysqltable.

Invoice_details

invoice_no   proje_ID invoice_Date invoice_amount
1004             6
1005             4
1006             2
1007             2
1008             1
1009             7

received_amount_details 

invoice_no        received_amount
1004                 205.00
1004                  40.00
1006                 283.50

Expected ouput: select from invoice_details where proje_ID =6
invoice no        invoice_amount   invoice_Date  received_amount
1004                                                  245.00

Expected ouput: select from invoice_details where proje_ID =2
invoice no        invoice_amount   invoice_Date  received_amount
1006                                                   283.50
1007                                                    0.00 (becoz 1007 invoice is not there in another table called received_amount_details so show total sum 0.00)

Expected ouput: select from invoice_details where proje_ID =7
    invoice no        invoice_amount   invoice_Date  received_amount
    1009                                                  0.00

这是我的查询：

public function many($id) {
   $sql = "SELECT invoice_details.invoice_No, invoice_details.invoice_Date, invoice_details.invoice_amount,
        SUM(received_amount_details.received_amount) as totalreceiptamt
        FROM 
          (SELECT DISTINCT invoice_no, received_amount FROM received_amount_details) AS received_amount_details 
      
         INNER JOIN invoice_details ON received_amount_details.invoice_no = invoice_details.invoice_No
         where invoice_details.proje_ID='7'
         group by invoice_details.invoice_No";

        return $this->db->query($sql)->result();
            }

如果我 select 发票详细信息 proje_ID='7'，目前我得到的结果是空的我必须在哪里更改我的 php 代码？

当我 select 一张发票（发票 no:1004）时，它会显示所有发票明细和总额 received_amount (205.00 + 40.00)。但是如果 select invoice (invoice no:1007) 正在获取空数据，因为此 1007 发票编号在第二个 table 中不存在。如果 received_amount_details table 中不存在，则仅 return 发票详细信息和总计 received_amount =0.00。（我想显示项目 ID =2 和总计 received_amount =0.00 的发票详细信息。）

Answer 1

在 SQL 查询中添加 IF 条件，类似这样。

SELECT invoice_details.invoice_no,
       invoice_details.invoice_date,
       invoice_details.invoice_amount,
       SUM(IF(received_amount_details.received_amount IS NULL
               OR received_amount_details.received_amount = '', 0.0,
               received_amount_details.received_amount)) AS totalreceiptamt
FROM   (SELECT DISTINCT invoice_no,
                        received_amount
        FROM   received_amount_details) AS received_amount_details
       right join invoice_details
               ON received_amount_details.invoice_no =
                  invoice_details.invoice_no
WHERE  invoice_details.proje_id = '7'
GROUP  BY invoice_details.invoice_no

这将添加 0.0，因为默认值不是 received_amount_details.received_amount IS NULL 或空白

此外，我们正在执行右连接以从 invoice_details 页面获取所有值。

您可以在 MYSQL 此处了解有关 IF 条件的更多信息，

https://www.w3schools.com/mysql/func_mysql_if.asp https://dev.mysql.com/doc/refman/8.0/en/if.html

如何在 mysql 加入时检查另一个 table 没有数据？

How to check in another table has no data while doing mysql join?

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