工会都会为此努力吗？答案

【问题标题】：Is union all going to work on this?工会都会为此努力吗？
【发布时间】：2018-05-18 14:21:09
【问题描述】：

我有两张表，收入和支出，尝试使用 union all，但问题是支出列显示在收入中，因此影响余额。知道我哪里出错了吗？

<?php
include "connection.php" ;

$result = mysql_query("select date, particulars, trntype, subincome, income, remarks,1 AS dummy from income UNION ALL select date, particulars, trntype, subexpense, expense,remarks, 2 AS dummy from expenditure ORDER BY `date` ASC, dummy ASC");
echo "<table border='1'>
<tr>
<th>Date</th>
<th>Particulars</th>
<th>Transaction Type</th>
<th>Sub Expense</th>
<th>Expense</th>
<th>Sub Income</th>
<th>Income</th>
<th>Cash In Hand</th>
<th>Remarks</th>
</tr>";

while($row = mysql_fetch_array($result))
  {
   echo "<tr>";
  echo "<td>" . $row['date'] . "</td>";
  echo "<td>" . $row['particulars'] . "</td>";
  echo "<td>" . $row['trntype'] . "</td>";
  echo "<td>" . $row['subexpense'] . "</td>";
  echo "<td>" . $row['expense'] . "</td>";
  echo "<td>" . $row['subincome'] . "</td>";
  echo "<td>" . $row['income'] . "</td>";
  $cashinhand = $cashinhand + $row['income'] + $row['income'] - $row['subexpense'] - $row['expense'] ;
    echo "<td>" . $cashinhand . "</td>";
      echo "<td>" . $row['remarks'] . "</td>";
  echo "</tr>";
  }
  echo "</table>";

?>

这里，在 Sub Expense 和 Expense 列中，不显示 subexpense 和费用，而是将它们打印到 Sub Income 和 Income 列中。自然，余额是增加而不是减少。

【问题讨论】：

标签： mysql sql html-table

【解决方案1】：

在您的查询中发生的情况是您将费用和收入混合在同一列中（第 3 列和第 4 列）。

尝试在每个查询不需要的列上添加null：

SELECT date,
       particulars,
       trntype,
       NULL as subexpense,
       NULL as expense,
       subincome,
       income,
       remarks,
       1 AS dummy
FROM   income
UNION ALL
SELECT date,
       particulars,
       trntype,
       subexpense,
       expense,
       NULL as subincome,
       NULL as income,
       remarks,
       2 AS dummy
FROM   expenditure
ORDER  BY `date` ASC,
          dummy ASC

这样，每个子查询的格式与预期的 HTML 输出相同，每个值类型都有不同的列。

【讨论】：

【解决方案2】：

您必须在每个查询中添加一个伪列以保持联合的分隔。

select date, particulars, trntype, subincome, income, 
  null as expence, remarks,1 AS dummy 
from income 
UNION ALL 
select date, particulars, trntype, subexpense, null as income, 
    expense, remarks, 2 AS dummy from expenditure ORDER BY `date` ASC, dummy ASC

【讨论】：