Mysql 将两个表的结果分组

我想将以下两个表的结果分组

项目结果

认证标准

使用以下连接/查找表：

课程\结果\认证\标准\查找

结果应该如下所示：

+-------------------+--------------------------+
| program_outcome 1 |  accreditation_standard 2 |
|                   |  accreditation_standard 5 |
|                   |  accreditation_standard 9 |
|                   |  ...                      |
+-------------------+--------------------------+
| program_outcome 2 |  accreditation_standard 3 |
|                   |  accreditation_standard 7 |
|                   |  accreditation_standard 8 |
|                   |  ...                      |
+-------------------+--------------------------+

等等

到目前为止，我已经尝试：

SELECT
    * 
FROM
    program_outcome,
    accreditation_standard,
    program_outcome_accreditation_standard_lookup
    LEFT JOIN accreditation_standard a_s ON a_s.accreditation_standard_pk = program_outcome_accreditation_standard_lookup.accreditation_standard_fk
    LEFT JOIN program_outcome p_o ON p_o.program_outcome_pk = program_outcome_accreditation_standard_lookup.program_outcome_fk 
GROUP BY
    p_o.program_outcome_pk

但上述查询不是根据上述连接/查找表中的program_Output.program_Output_fk对Accuration_standard.Accuration_standard_fk进行分组

我可能应该使用GROUP_CONCAT，但不确定如何在上面实现。我使用的是MySQL v5.5

看小提琴

我将结果格式化如下：

$result = $connection->query( $query );

echo "<table width='100%' border='1'><thead><tr><th>Program Outcomes</th><th>Accreditation Standards</th></tr></thead><tbody>";
while ($row = mysqli_fetch_array($result)) {
echo "<tr><td>" . $row['program_outcome'] . "</td><td>" . $row['accreditation_standard']  . "</td></tr>";
}
echo "<tbody></table>";

---

我不确定映射是否正确，您可以自己修改它

SELECT
    CONCAT( 'program_outcome ', p_o.program_outcome_pk ) AS popk,
    GROUP_CONCAT( DISTINCT CONCAT( 'accreditation_standard  ', a_s.accreditation_standard_pk ) SEPARATOR "\r\n" ) AS aspk 
FROM
    program_outcome,
    accreditation_standard,
    program_outcome_accreditation_standard_lookup
    LEFT JOIN accreditation_standard a_s ON a_s.accreditation_standard_pk = program_outcome_accreditation_standard_lookup.accreditation_standard_fk
    LEFT JOIN program_outcome p_o ON p_o.program_outcome_pk = program_outcome_accreditation_standard_lookup.program_outcome_fk 
GROUP BY
    p_o.program_outcome_pk

---

我不确定映射是否正确，您可以自己修改它

SELECT
    CONCAT( 'program_outcome ', p_o.program_outcome_pk ) AS popk,
    GROUP_CONCAT( DISTINCT CONCAT( 'accreditation_standard  ', a_s.accreditation_standard_pk ) SEPARATOR "\r\n" ) AS aspk 
FROM
    program_outcome,
    accreditation_standard,
    program_outcome_accreditation_standard_lookup
    LEFT JOIN accreditation_standard a_s ON a_s.accreditation_standard_pk = program_outcome_accreditation_standard_lookup.accreditation_standard_fk
    LEFT JOIN program_outcome p_o ON p_o.program_outcome_pk = program_outcome_accreditation_standard_lookup.program_outcome_fk 
GROUP BY
    p_o.program_outcome_pk

---

这不是一个普通的连接吗。。？希望我能正确理解你的问题：

SELECT program_outcome, 
accreditation_standard
FROM program_outcome p
JOIN program_outcome_accreditation_standard_lookup l ON p.program_outcome_pk = l.program_outcome_fk
JOIN accreditation_standard a ON l.accreditation_standard_fk = a.accreditation_standard_pk;

在下面的小提琴中检查结果。或下面的查询。基本上相同的结果只是更接近您的预期结果

SELECT program_outcome, 
GROUP_CONCAT(accreditation_standard SEPARATOR "\r\n") AS accreditation_standard
FROM program_outcome p
JOIN program_outcome_accreditation_standard_lookup l ON p.program_outcome_pk = l.program_outcome_fk
JOIN accreditation_standard a ON l.accreditation_standard_fk = a.accreditation_standard_pk
GROUP BY program_outcome;

---

顺便说一句，你的字段命名选择给我留下了深刻的印象。

这不是一个普通的连接吗。。？希望我能正确理解你的问题：

SELECT program_outcome, 
accreditation_standard
FROM program_outcome p
JOIN program_outcome_accreditation_standard_lookup l ON p.program_outcome_pk = l.program_outcome_fk
JOIN accreditation_standard a ON l.accreditation_standard_fk = a.accreditation_standard_pk;

在下面的小提琴中检查结果。或下面的查询。基本上相同的结果只是更接近您的预期结果

SELECT program_outcome, 
GROUP_CONCAT(accreditation_standard SEPARATOR "\r\n") AS accreditation_standard
FROM program_outcome p
JOIN program_outcome_accreditation_standard_lookup l ON p.program_outcome_pk = l.program_outcome_fk
JOIN accreditation_standard a ON l.accreditation_standard_fk = a.accreditation_standard_pk
GROUP BY program_outcome;

---

顺便说一句，您的字段命名选择给我留下了深刻的印象。

这是前两个答案的最终有效解决方案

  $query = "SELECT program_outcome, 
    GROUP_CONCAT(accreditation_standard SEPARATOR '|') AS accreditation_standards
    FROM program_outcome p
    JOIN program_outcome_accreditation_standard_lookup l ON p.program_outcome_pk = l.program_outcome_fk
    JOIN accreditation_standard a ON l.accreditation_standard_fk = a.accreditation_standard_pk
    GROUP BY program_outcome";
    
        $result = $connection->query( $query );
        
        echo "<table width='100%' border='1'><thead><tr><th>Program Outcomes</th><th>Accreditation Standards</th></tr></thead><tbody>";
        while ($row = mysqli_fetch_array($result)) {
        echo "<tr><td>" . $row['program_outcome'] . "</td><td>" . str_replace('|', '<p>',$row['accreditation_standards']) . "</td></tr>";
        }
        echo "<tbody></table>";

---

这是前两个答案的最终有效解决方案

  $query = "SELECT program_outcome, 
    GROUP_CONCAT(accreditation_standard SEPARATOR '|') AS accreditation_standards
    FROM program_outcome p
    JOIN program_outcome_accreditation_standard_lookup l ON p.program_outcome_pk = l.program_outcome_fk
    JOIN accreditation_standard a ON l.accreditation_standard_fk = a.accreditation_standard_pk
    GROUP BY program_outcome";
    
        $result = $connection->query( $query );
        
        echo "<table width='100%' border='1'><thead><tr><th>Program Outcomes</th><th>Accreditation Standards</th></tr></thead><tbody>";
        while ($row = mysqli_fetch_array($result)) {
        echo "<tr><td>" . $row['program_outcome'] . "</td><td>" . str_replace('|', '<p>',$row['accreditation_standards']) . "</td></tr>";
        }
        echo "<tbody></table>";

---

在MySQL中预期的结果是这样的吗？不，我可以使用PHP和HTML格式化结果…请参阅更新的OPI。我认为您可以简化您的示例，但如果我理解正确，您正在尝试使用pivot，GROUP的方式为每个组获取一行。如果你想把它们放在连续的行上，使用ORDER By谢谢你的信息和建议，我以后一定会看的。现在，我将最终的解决方案放在一个单独的答案中，而不是放在OP中。在MySQL中，预期结果会是这样吗？不，我可以使用PHP和HTML格式化结果…请参阅更新的OPI。我认为您可以简化您的示例，但如果我理解正确，您正在尝试使用pivot、GROUP的方法，即为每个组获取一行。如果你想把它们放在连续的行上，使用ORDER By谢谢你的信息和建议，我以后一定会看的。我现在把最后的解决方案放在一个单独的答案中，而不是放在OP中。两个答案都有效，只需稍作修改，格式就是所需的。我已经更新了OP，以显示具有所需格式的最终工作解决方案。如果可以的话，我会给出两种正确的解决方案，但我选择了最简单的一种……也许你想解释一下为什么像上面评论中提到的@tcadidot0那样使用逗号连接和左连接？抱歉，错过了……混合方法？否则没有理由。@Tenderfoot的“OP”是你。两个答案都有效，只需稍作更改，格式就是必需的。我已经更新了OP，以显示具有所需格式的最终工作解决方案。如果可以的话，我会给出两种正确的解决方案，但我选择了最简单的一种……也许你想解释一下为什么像上面评论中提到的@tcadidot0那样使用逗号连接和左连接？抱歉，错过了……混合方法？否则就没有理由了，“OP”就是你。