mysql結合を実行しているときに別のテーブルにデータがないことを確認する方法は？

SQLクエリにIF条件を追加します。このようなものです。

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 

デフォルト値が受信されないため、これにより0.0が追加されます_amount_details.received_amountISNULLまたは空白

また、invoice_detailsページからすべての値を取得するために右結合を実行しています。

MYSQLのIF条件について詳しくは、こちらをご覧ください

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