我在PHP中创建了一个函数，使用JOIN和WHERE从表中查询数据。 此函数不显示任何错误。 当var_dump完成时，它将显示函数返回的以下语句。

var_dump:
string(8) "2ingnams" object(PDOStatement)#3 (1) { ["queryString"]=> string(102) "SELECT * FROM jobs INNER JOIN categories ON jobs.categoryId = categories.cId WHERE client_id = :value " }

这里而不是':value'$_session值应该在这里

function:
public function multi($tae2, $tae1_id, $tae2_id, $ky, $vae)
    {
        $joinTableQuery = "SELECT * FROM $this->table_name INNER JOIN $tae2 ON $this->table_name.$tae1_id = $tae2.$tae2_id WHERE $ky = :vae ";
        $exec = $this->pdo->prepare($joinTableQuery);
        $criteria = [
            'vae' => $vae
        ];
        $exec->execute($criteria);
        return $exec;
    }

调用的函数:

$cd= new DatabaseTables($pdo,'jobs');
$stmt = $cd->multi('categories','categoryId','cId','client_id',$_SESSION['sesClientLogin']);