PHP 在线操作 Sqlite 报错

<?php
class MyDB extends SQLite3
{
function __construct()
{
$this->open('test.db3');
}
}
$qb=$_POST["bank"];
if not(is_null($qb)){
$db = new MyDB();
if(!$db){
echo $db->lastErrorMsg();
}
$sql = "SELECT * FROM aps WHERE bank LIKE". $qb;

$ret = $db->query($sql);
while($row = $ret->fetchArray(SQLITE3_ASSOC) ){
echo "<p>";
echo "ID = ". $row['bank'] . "\n";
echo "NAME = ". $row['aps'] ."\n";
echo "</P>";
}
echo "查询结束。";
$db->close();
}
?>
<form action=aps.php method=post><p>银行名称模糊查询<input type=text name=bank /></p><input type=submit value=查询 /></form>


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单页面查询，一个单数据库，十五万银行数据，2 个表。