基本上我想使用 php PDO 创建一个查询来检查我的数据库“test”中是否存在表“page”。我不知道该怎么做，我在这里得到了一些帮助。
我的代码运行完美......直到现在我把所有东西都放在课堂上......现在var_dump($r2)返回NULL，我不知道代码有什么问题。除了将它放入OOP之外，我没有改变任何东西......
谁能发现问题？？因为我看不到。谢谢你
$r1 = $this->db->query('SHOW TABLES LIKE \'page\'');
// Debbug
$r2 = $r1->fetchAll;
var_dump ($r2);
if (count($r1->fetchAll()) > 0 ) {
echo "The table PAGE exists";
}
完整的类是以下一个
class phase2 {
function __construct () {
$dbFile = 'dbconfig.php';
$this->dbFile = $dbFile;
require_once ("$dbFile");
$step = $_GET["step"];
$username = $DB_USER;
$password = $DB_PASS;
$server = $DB_SERVER;
$dbName = $DB_NAME;
$this->step = $step;
$this->dbFile = $dbFile;
$this->username = $username;
$this->password = $password;
$this->server = $server;
$this->dbName = $dbName;
$db = new PDO ('mysql:host=' .$server.';dbname='.$this->dbName,$this->username,$this->password);
$this->db = $db;
if (empty ($_GET['fot']) ) {
$fOT = 'false';
} elseif ($_GET['true']) { $fOT = 'true'; }
$this->fOT = $fOT;
$this->IDB = $this->handleDatabase( 1 );
$this->IDB2 = $this->handleDatabase( 2 );
$this->IDB3 = $this->handleDatabase( 3 );
}
public function handleDatabase ($num = 1){
// Prepare SQL Statements
$IDB1 = $this->db->prepare(
"CREATE TABLE pages (
id int(11) NOT NULL auto_increment,
subject_id int(11) NOT NULL,
menu_name varchar(30) NOT NULL,
position int(3) NOT NULL,
visible tinyint(1) NOT NULL,
content text NOT NULL,
PRIMARY KEY (id)
)ENGINE=MyISAM AUTO_INCREMENT=7 DEFAULT CHARSET=utf8");
$IDB2 = $this->db->prepare("
CREATE TABLE subjects (
id int(11) NOT NULL auto_increment,
menu_name varchar(30) NOT NULL,
position int(3) NOT NULL,
visible tinyint(1) NOT NULL,
PRIMARY KEY (id)
)ENGINE=MyISAM AUTO_INCREMENT=6 DEFAULT CHARSET=utf8");
$IDB3 = $this->db->prepare("
CREATE TABLE users (
id int(11) NOT NULL auto_increment,
username varchar(50) NOT NULL,
hashed_password varchar(40) NOT NULL,
PRIMARY KEY (id)
)ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=utf8");
$name = "IDB".$num;
return isset( $$name)?$$name:false;
}
//Set Option to True or False
function createTablePages ($fOT){
$r1 = $this->db->query('SHOW TABLES LIKE \'page\'');
// Debbug
$r2 = $r1->fetchAll;
var_dump ($r2);
if (count($r1->fetchAll()) > 0) {
echo "The table PAGE exists";
} elseif ($fOT == 'true') {
echo "enteres";
$this->IDB1->execute();
$this->stepFunction (1,false);
}
}
function createTableSubjects ($fOT){
$r2 = $this->db->query('SHOW TABLES LIKE \'subjects\'');
if (count($r2->fetchAll()) > 0 && $fOT == 'false') {
echo "The table SUBJECTS exists ";
} elseif ($fOT == 'true') {
$this->IDB2->execute();
$this->stepFunction (2,false);
}
}
function createTableUsers ($fOT){
$r3 = $this->db->query('SHOW TABLES LIKE \'users\'');
if (count($r3->fetchAll()) > 0 && $fOT == 'false') {
echo "The table USERS exists";
} elseif ($fOT == 'true') {
$this->IDB3->execute();
echo "Would you like to populate all the tables?";
}
}
public function stepFunction ($fOT,$step){
switch ($step) {
case 0:
$this->createTablePages ($fOT);
break;
case 1:
$this->createTableSubjects($fOT);
break;
case 2: $this->createTableUsers ($fOT);
break;
}
}
}