如何组合多个 mySQL 查询？

Question

我是 mySQL 的新手。我有多个查询 sql 要组合，我正在使用 php 和 mySQL。如何组合查询？我需要在表格的一行中显示查询的所有结果。

<?php
$query1="SELECT s.staffName, s.staffNo, g.grade, g.gradePosition, g.gradeDepartment 
			FROM tblstaff s, tblgrade g where s.staffNo=g.staffNo";		
	$result=mysql_query($query1) or die (mysql_error());		
	while($row= mysql_fetch_array($result))
	{
	?>
		<td><?php echo $row['staffName']; ?></td> <!--display staff name-->
		<td><?php echo $row['staffNo']; ?></td> <!--display staff number-->
		<td><?php echo $row['grade']; ?></td> <!--display staff grade-->
		<td><?php echo $row['gradePosition']; ?></td> <!--display staff position-->
		<td><?php echo $row['gradeDepartment']; ?></td><!--display staff department-->
		<tr>
	
<?php
  }
?>	

<?php
$query2="select catTechnical, catOtherTechnical, catTechnicalDescription, catOtherTechnicalDescription, catWeightage,
			perReqScore		
			from tblcategory c join tblperformance p on c.catID=p.catID";	
	$result=mysql_query($query2) or die (mysql_error());	
	while($row= mysql_fetch_array($result))
	{
	?>
		<td><?php echo $row['catTechnical']; ?></td> <!--display technical category-->
		<td><?php echo $row['catTechnicalDescription']; ?></td> <!--display technical description-->
		<td><?php echo $row['catOtherTechnicalDescription']; ?></td> <!--display other technical description-->
		<td><?php echo $row['catWeightage']; ?></td> <!--display weightage-->
		<td><?php echo $row['perReqScore']; ?></td <!--display required score-->
<?php
}
?>

这是我的数据库表。

tblstaff

+---------+-----------+
| staffNo | staffName |
+---------+-----------+
| 1002435 | Fadzlan   |
+---------+-----------+

tblgrade

+---------+---------+-------+---------------+-----------------+
| gradeID | staffNo | grade | gradePosition | gradeDepartment |
+---------+---------+-------+---------------+-----------------+
|       1 | 1002435 | E14   | Manager       | IB              |
+---------+---------+-------+---------------+-----------------+

tblcategory

+-------+--------------+---------------------------+-------------------------+--------------+
| catID | catTechnical |     catOtherTechnical     | catTechnicalDescription | catWeightage |
+-------+--------------+---------------------------+-------------------------+--------------+
|    18 | Project(18)  | Project Coordination(181) |                      30 |              |
+-------+--------------+---------------------------+-------------------------+--------------+

tbl 性能

+-------+-------+----------+-------------+
| perID | catID | staffNo  | perReqScore |
+-------+-------+----------+-------------+
|     1 |    18 | 10028531 |           4 |
+-------+-------+----------+-------------+

这是我当前的代码和数据库表。我需要将查询 1 和查询 2 组合起来，因为我想通过 staffNo 在表的一行中显示结果。我的意思是一个工作人员没有表中的一行。然后其他staffNo会显示到同一张表的新行中。

Answer 1

在您的第三个查询中，不清楚哪些列在哪个表中。既然您说所有结果都需要显示在一行中，我假设 s.staffNo = g.staffNo 仅适用于一对行，并且 c.catID = p.catID 仅适用于一对行。然后你可以使用JOIN。不过，我建议添加短表名。 UNION 将不起作用，因为它用于组合等长和等列类型的行集。

编辑：添加了c. 和p. 请不要使用mysql_query，它已被弃用。请改用mysqli_query。我不确定这个数据库是否以最好的方式设计。你不能把所有东西都合并到 tblstaff 中吗？

SELECT s.staffName, s.staffNo, g.grade, g.gradePosition, g.gradeDepartment, 
c.catTechnical, c.catOtherTechnical, c.catTechnicalDescription, c.catOtherTechnicalDescription, c.catWeightage, p.perReqScore, p.perActScore, p.perAction, p.perOtherAction, p.perTrainingIlsas, p.perTrainingPublic
FROM tblstaff s
JOIN tblgrade g ON s.staffNo = g.staffNo
JOIN tblcategory c
JOIN tblperformance p on c.catID = p.catID

Answer 2

除了join tblperformance p on s.staffNo=p.staffNo之外，你都已经完成了

SELECT s.staffName, s.staffNo, g.grade, g.gradePosition, g.gradeDepartment 
c.catTechnical, c.catOtherTechnical, c.catTechnicalDescription,
c.catOtherTechnicalDescription, c.catWeightage, p.perReqScore

FROM tblstaff s
join tblgrade g on s.staffNo=g.staffNo
join tblperformance p on s.staffNo=p.staffNo
join tblcategory c on p on c.catID=p.catID

Answer 3

SELECT s.staffName, s.staffNo, g.grade, g.gradePosition, g.gradeDepartment,
   c.catTechnical, c.catOtherTechnical, c.catTechnicalDescription, 
   c.catOtherTechnicalDescription, c.catWeightage, c.perReqScore, c.perActScore, 
   c.perAction, c.perOtherAction, c.perTrainingIlsas, c.perTrainingPublic
FROM tblstaff s, tblgrade g, tblcategory c
JOIN tblperformance p on c.catID = p.catID
WHERE s.staffNo = g.staffNo;