mysql - sql - UNION ALL 和另一侧的内连接

Question

我想要查询想要实现的位置 与我的内部连接具有相同的值(value) 应该是它们作为第一个值的唯一值 列，如图所示:

而我只想输出的是图中的红线。

这是我的疑问:

  SELECT it.Date AS 'Date', it.invoice AS 'Invoice No.', 
         it.company AS 'Company', it.total_amount AS 'Total Amount'
  FROM invoicesummary_tbl it
  WHERE it.total !=0 
  UNION ALL
  SELECT itt.Date AS 'Date',rt.revises_no AS 'Invoice_No.', itt.company AS 
  'Company', 
       itt.total_amount AS 'Total Amount'   
  FROM revises_tbl rt
  INNER JOIN invoicesummary_tbl itt
  ON itt.invoice=rt.invoice

Answer 1

使用DISTINCT关键字:

SELECT DISTINCT *
  FROM (SELECT it.Date AS 'Date',
               it.invoice AS 'Invoice No.',
               it.company AS 'Company',
               it.total_amount AS 'TotalAmount'
          FROM invoicesummary_tbl it
         WHERE it.total != 0
        UNION ALL
        SELECT itt.Date AS 'Date',
               rt.revises_no AS 'Invoice_No.',
               itt.company AS 'Company',
               itt.total_amount AS 'Total Amount'
          FROM revises_tbl rt
               INNER JOIN invoicesummary_tbl itt ON itt.invoice = rt.invoice
) AS a