MySQLのテーブル定義をPHPで出力する

参考：https://qiita.com/arc279/items/0a3895a04fc814512baf

<?php

$dsn = "mysql:host=127.0.0.1;port=3306;charset=utf8";
$user = "root";
$pass = "";
$DBNAME = "employees";

$SQL_TABLE_INFO = <<<EOD
SELECT
    TABLE_NAME,
    TABLE_COMMENT
  FROM INFORMATION_SCHEMA.TABLES
    WHERE table_schema = '$DBNAME'
EOD;

$SQL_COLUMN_INFO = <<<EOD
SELECT
    COLUMN_NAME,
    COLUMN_DEFAULT,
    IS_NULLABLE,
    COLUMN_TYPE,
    COLLATION_NAME,
    COLUMN_KEY,
    EXTRA,
    COLUMN_COMMENT
  FROM INFORMATION_SCHEMA.COLUMNS
    WHERE table_schema = '$DBNAME'
    AND table_name LIKE :tbl
EOD;

function each_tables($pdo, $dbname, $callback) {
    global $SQL_TABLE_INFO;
    global $SQL_COLUMN_INFO;

    $stmt1 = $pdo->query($SQL_TABLE_INFO);

    while(false != ($tblinfo = $stmt1->fetch(PDO::FETCH_ASSOC))) {
        $tblname = $tblinfo["TABLE_NAME"];

        $stmt2 = $pdo->prepare($SQL_COLUMN_INFO);
        $ret2 = $stmt2->execute(array(":tbl" => $tblname));
        if($ret2 === false) {
            throw new Exception($tblname);
        }
        $colinfo = $stmt2->fetchAll(PDO::FETCH_ASSOC);

        $callback($tblinfo, $colinfo);
    }
}


function genHtml($pdo, $dbname) {
    $str = <<<'EOD'
?>
<meta charset="utf-8">

<?php
each_tables($pdo, $dbname, function($tblinfo, $colinfo) {
?>
<fieldset>
    <legend><?= $tblinfo["TABLE_NAME"] ?></legend>
    <p><?= $tblinfo["TABLE_COMMENT"] ?></p>
    <table border="1">
        <tr>
<?php foreach(array_keys($colinfo[0]) as $key): ?>
            <th><?= $key ?></th>
<?php endforeach; ?>
        </tr>

<?php foreach($colinfo as $col): ?>
        <tr>
<?php foreach($col as $key => $val): ?>
            <td><?= $val ?></td>
<?php endforeach; ?>
        </tr>
<?php endforeach; ?>
    </table>
</fieldset>

<?php
});
?>
EOD;

    eval($str);
}

try {
    $pdo = new PDO($dsn, $user, $pass);
    genHtml($pdo, $DBNAME);
} catch(Exception $e) {
    var_dump($e);
    throw $e;
}