pdo

问题 I'd like to select some data from my database using variables. Here is a short version of my code: // $a is either null or something like [1, 2] if ($a) { $debug = implode(',', $a); } else { $debug = [0-9]; } $sql = "SELECT id FROM user WHERE id IN ($debug)" How can I achieve that I get only user 1 and 2 (= value in $a ) if $a is set and all user if $a is not set? 回答1: First : be aware when you directly inject string inside queries, because you can be target of a SQL Injection Second : change

问题 I'd like to select some data from my database using variables. Here is a short version of my code: // $a is either null or something like [1, 2] if ($a) { $debug = implode(',', $a); } else { $debug = [0-9]; } $sql = "SELECT id FROM user WHERE id IN ($debug)" How can I achieve that I get only user 1 and 2 (= value in $a ) if $a is set and all user if $a is not set? 回答1: First : be aware when you directly inject string inside queries, because you can be target of a SQL Injection Second : change

问题 I've found a contradiction I could not understand. Exception::getCode() has this definition: final public Exception::getCode ( void ) : mixed with description: Returns the exception code as integer in Exception but possibly as other type in Exception descendants (for example as string in PDOException) but the Exception class implements Throwable interface that defines: abstract public getCode ( void ) : int So how for an example PDOException as a descendant of Exception could return string

问题 I've found a contradiction I could not understand. Exception::getCode() has this definition: final public Exception::getCode ( void ) : mixed with description: Returns the exception code as integer in Exception but possibly as other type in Exception descendants (for example as string in PDOException) but the Exception class implements Throwable interface that defines: abstract public getCode ( void ) : int So how for an example PDOException as a descendant of Exception could return string

问题 I am reading this answer: PHP - Using PDO with IN clause array It uses the code: $in_array = array(1, 2, 3); $in = str_repeat('?,', count($in_array) - 1) . '?'; $sql = "SELECT * FROM my_table WHERE my_value IN ($in)"; $stm = $db->prepare($sql); $stm->execute($in_array); $data = $stm->fetchAll(); Can anyone explain why they used $in = str_repeat('?,', count($in_array) - 1) . '?'; instead off: $in = str_repeat('?,', count($in_array)); I am puzzled and cannot figure out the logic behind the

问题 There is a following code: <?php include 'connection.php'; //$db is declared here. It's a PDO object. foreach ($db->query("SELECT * FROM names") as $row) { echo $row['firstname'] . $row['lastname'] . $row['postcode'] . '<br>'; } ?> The code works as expected, but I don't understand the logic behind it. I've read on php.net that PDO::query() returns a PDOStatement object as a result set. So teoretically, this part: $db->query("SELECT * FROM names") is a PDOStatement object. How does foreach

问题 There is a following code: <?php include 'connection.php'; //$db is declared here. It's a PDO object. foreach ($db->query("SELECT * FROM names") as $row) { echo $row['firstname'] . $row['lastname'] . $row['postcode'] . '<br>'; } ?> The code works as expected, but I don't understand the logic behind it. I've read on php.net that PDO::query() returns a PDOStatement object as a result set. So teoretically, this part: $db->query("SELECT * FROM names") is a PDOStatement object. How does foreach

问题 Can I use a few lines in the parameter Example SELECT id, city_id FROM an_objects WHERE city_id IN (:arrCity) (:arrCity) (1,2,3,4,5,6) But now I have done like this SELECT id, city_id FROM an_objects WHERE city_id IN (:1p, :2p, :3p, ...... :100p) And it's very bad 回答1: <?php private function PDOBindArray(&$poStatement, &$paArray){ foreach ($paArray as $k=>$v) { @$poStatement->bindValue($k, $v[0], $v[1]); } } // the array structure should now look something like this $inputArray = array( '

问题 Can I use a few lines in the parameter Example SELECT id, city_id FROM an_objects WHERE city_id IN (:arrCity) (:arrCity) (1,2,3,4,5,6) But now I have done like this SELECT id, city_id FROM an_objects WHERE city_id IN (:1p, :2p, :3p, ...... :100p) And it's very bad 回答1: <?php private function PDOBindArray(&$poStatement, &$paArray){ foreach ($paArray as $k=>$v) { @$poStatement->bindValue($k, $v[0], $v[1]); } } // the array structure should now look something like this $inputArray = array( '

问题 Can I use a few lines in the parameter Example SELECT id, city_id FROM an_objects WHERE city_id IN (:arrCity) (:arrCity) (1,2,3,4,5,6) But now I have done like this SELECT id, city_id FROM an_objects WHERE city_id IN (:1p, :2p, :3p, ...... :100p) And it's very bad 回答1: <?php private function PDOBindArray(&$poStatement, &$paArray){ foreach ($paArray as $k=>$v) { @$poStatement->bindValue($k, $v[0], $v[1]); } } // the array structure should now look something like this $inputArray = array( '