[英]How to get mysql Group_Concat to work with additional CONCAT information?
我正在開發一個帶有mysql的Web應用程序,其中涉及一個用戶角色表,其中存儲了權限級別以及角色ID,並與用戶名及其ID相關聯(冗余以繼續支持遺留代碼)。
我希望能夠以簡單的英語顯示每個用戶的角色作為逗號分隔列表,對數據庫(> 1k用戶)的最小命中以及他們的權限級別。
權限存儲為ismanager和ishead列中的位,而roleid則鍵入define_roles(id,rolename)
這是我的工作(但沒有顯示用戶級別)
<?
$rolenames = array();
foreach($db->query("SELECT id, rolename FROM define_roles") as $row)
{
$rolenames[$row['id']] = $row['rolename'];
}
foreach($db->query("SELECT DISTINCT userid, username,
GROUP_CONCAT(DISTINCT roleid ORDER BY roleid) AS idlist
FROM user_roles
GROUP BY userid
ORDER BY username ASC") as $row)
{
$rolestring = '';
//echo $row['idlist'];
foreach(explode(',',$row['idlist']) as $id)
{
$rolestring .= " ".$rolenames[$id].",";
}
$rolestring = rtrim($rolestring,',');
echo "<tbody>
<tr>
<td><font size='1'>" . $row['username'] . "</font></td>
<td><font size='1'>" .$rolestring. "</font></td>
</tr>";
}
?>
輸出:
我想看到的是
我能想到的最好(盡管它不起作用)是:
$rolenames = array();
foreach($db->query("SELECT id, rolename FROM define_roles") as $row)
{
$rolenames[$row['id']] = $row['rolename'];
$rolenames[$row['id']."10"] = $row['rolename']." (Manager)";
$rolenames[$row['id']."01"] = $row['rolename']." (Head)";
$rolenames[$row['id']."11"] = $row['rolename']." (Head)";
}
foreach($db->query("SELECT DISTINCT userid, username,
GROUP_CONCAT
(
CONCAT(roleid,ismanager,ishead) ORDER BY roleid
) AS idlist
FROM user_roles
GROUP BY userid
ORDER BY username ASC") as $row)
首先,您應該規范化數據庫,以便有一個單獨的表鏈接用戶和已定義的角色。 但這是一個單獨的事情,我感謝你可能無法做到這一點。
如果我已經正確理解了你桌子上的內容,答案就是這個,我想:
SELECT
userid,
username,
GROUP_CONCAT(DISTINCT
CONCAT(
(SELECT d.rolename FROM define_roles AS d
WHERE d.id = roleid)
),
IF(ismanager = 1, " (Manager)", ""),
IF(ishead = 1, " (Head)", "")
) AS roles
FROM user_roles
GROUP BY userid;
您不需要初始sql,您可以從define_roles中查找角色名稱。
[編輯]:抱歉,更新內部SELECT周圍的括號。
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