php MySQL 用逗号分隔值连接两个表
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MySQL Join two tables with comma separated values
提问by 626
I have 2 tables as below
我有 2 张表，如下所示
Notes Table
备注表
╔══════════╦═════════════════╗
║ nid ║ forDepts ║
╠══════════╬═════════════════╣
║ 1 ║ 1,2,4 ║
║ 2 ║ 4,5 ║
╚══════════╩═════════════════╝
Positions Table
职位表
╔══════════╦═════════════════╗
║ id ║ name ║
╠══════════╬═════════════════╣
║ 1 ║ Executive ║
║ 2 ║ Corp Admin ║
║ 3 ║ Sales ║
║ 4 ║ Art ║
║ 5 ║ Marketing ║
╚══════════╩═════════════════╝
I am looking to query my Notes table and associate the 'forDepts' column with values from the Positions table.
我希望查询我的 Notes 表并将 'forDepts' 列与 Positions 表中的值相关联。
The output should be:
输出应该是：
╠══════════╬════════════════════════════╣
║ 1 ║ Executive, Corp Admin, Art ║
║ 2 ║ Art, Marketing ║
╚══════════╩════════════════════════════╝
I know that the database should be normalized but I cannot change the database structure for this project.
我知道应该规范化数据库，但我无法更改此项目的数据库结构。
This is going to be used to export a excel file with the code below.
这将用于导出带有以下代码的 excel 文件。
<?PHP
$dbh1 = mysql_connect($hostname, $username, $password);
mysql_select_db('exAdmin', $dbh1);
function cleanData(&$str)
{
$str = preg_replace("/\t/", "\t", $str);
$str = preg_replace("/\r?\n/", "\n", $str);
if(strstr($str, '"')) $str = '"' . str_replace('"', '""', $str) . '"';
}
$filename = "eXteres_summary_" . date('m/d/y') . ".xls";
header("Content-Disposition: attachment; filename=\"$filename\"");
header("Content-Type: application/vnd.ms-excel");
//header("Content-Type: text/plain");
$flag = false;
$result = mysql_query(
"SELECT p.name, c.company, n.nid, n.createdOn, CONCAT_WS(' ',c2.fname,c2.lname), n.description
FROM notes n
LEFT JOIN Positions p ON p.id = n.forDepts
LEFT JOIN companies c ON c.userid = n.clientId
LEFT JOIN companies c2 ON c2.userid = n.createdBy"
, $dbh1);
while(false !== ($row = mysql_fetch_assoc($result))) {
if(!$flag) {
$colnames = array(
'Created For' => "Created For",
'Company' => "Company",
'Case ID' => "Case ID",
'Created On' => "Created On",
'Created By' => "Created By",
'Description' => "Description"
);
// display field/column names as first row
echo implode("\t", array_keys($colnames)) . "\r\n";
$flag = true;
}
$row['createdOn'] = date('m-d-Y | g:i a', strtotime($row['createdOn']));
array_walk($row, 'cleanData');
echo implode("\t", array_values($row)) . "\r\n";
}
exit;
?>
This code outputs only the first value of 'forDepts'
此代码仅输出 'forDepts' 的第一个值
Exa: Executive (instead of Executive, Corp Admin, Art)
Exa：Executive（而不是Executive、Corp Admin、Art）
Can this be accomplished by CONCAT or FIND_IN_SET?
这可以通过 CONCAT 或 FIND_IN_SET 来完成吗？
Please help! Thanks in advance!
请帮忙！提前致谢！
回答by John Woo
SELECT a.nid,
GROUP_CONCAT(b.name ORDER BY b.id) DepartmentName
FROM Notes a
INNER JOIN Positions b
ON FIND_IN_SET(b.id, a.forDepts) > 0
GROUP BY a.nid
回答by Tirthraj Singh Bartwal
Table 1
╔══════════╦═════════════════╗
║ nid ║ forDepts ║
╠══════════╬═════════════════╣
║ 1 ║ 1,2,4 ║
║ 2 ║ 4,5 ║
╚══════════╩═════════════════╝
Table 2
╔══════════╦═════════════════╗
║ id ║ name ║
╠══════════╬═════════════════╣
║ 1 ║ Executive ║
║ 2 ║ Corp Admin ║
║ 3 ║ Sales ║
║ 4 ║ Art ║
║ 5 ║ Marketing ║
╚══════════╩═════════════════╝
SELECT * FROM table1 as t1 LEFT JOIN table2 as t2 ON find_in_set(t2.id,
t1.forDepts)
Output
╠══════════╬════════════════════════════╣
║ 1 ║ Executive, Corp Admin, Art ║
║ 2 ║ Art, Marketing ║
╚══════════╩════════════════════════════╝
