下文主要給大家帶來PDO與MySQLi各自優勢及該如何選擇,希望這些內容能夠帶給大家實際用處,這也是我編輯PDO與MySQLi各自優勢及該如何選擇這篇文章的主要目的。好了,廢話不多說,大家直接看下文吧。
PDO的優勢
1.有用的獲取方式
2.允許直接將變量和值傳遞給execute
3.能夠自動檢測變量類型(實際發生的情況是,發送到云服務器時,所有內容都被視為字符串,但被轉換為正確的類型。這在預處理語句中100%有效,但在某些邊緣情況下無效,比如在模擬模式中。)
4.提供一個選項,使用預處理語句自動緩沖結果
5.命名參數(盡管在PDO中關閉模擬模式是無用的,因為你只能使用相同的名稱一次)
MySQLi優勢
1.異步查詢
2.獲取有關受影響行的更多信息的能力,比如更新具有相同值的行(可以在PDO中作為構造函數設置完成,以后無法更改)
3.正確的數據庫關閉方法
4.一次多個查詢(如果在PDO中打開模擬模式,則可以)
5.使用持久連接自動清除
代碼的差異
PDO和MySQLi非常相似,但是在語法上略有不同。MySQLi遵循舊式的PHP snake_case約定,而PDO使用camelCase。此外,MySQLi的方法被用作對象屬性,而PDO對函數使用傳統語法。
PDO和MySQLi都要求你使用兩個單獨的方法來使用預處理語句,從而使事情變得復雜。不過PDO消除了使用專用綁定函數的需要。
例如,在特定于供應商的PostgreSQL API中,你可以這樣做。
下面是一個示例,演示如何執行一個“non-prepared”查詢來獲取一個包含MySQLi和PDO的關聯數組,以供參考。
$arr = $mysqli->query("SELECT * FROM myTable")->fetch_all(MYSQLI_ASSOC);
$arr = $pdo->query("SELECT * FROM myTable")->fetchAll(PDO::FETCH_ASSOC);
實際上,最好的方法是使用包裝器、查詢生成器或ORM。雖然PDO可以直接將值綁定到execute中,但它仍然不是理想的。在我創建的類中,你可以鏈接所有調用,同時傳入值作為參數參數綁定。
$arr = $mysqli->query("SELECT * FROM myTable WHERE id > ?", [12])->fetchAll('assoc');
現在,在變量中以更簡潔的方式存儲了整個關聯數組。
創建一個新的數據庫連接
PDO
$dsn = "mysql:host=localhost;dbname=myDatabase;charset=utf8mb4";$options = [ PDO::ATTR_EMULATE_PREPARES => false, // turn off emulation mode for "real" prepared statements PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, //turn on errors in the form of exceptions PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC, //make the default fetch be an associative array];try { $pdo = new PDO($dsn, "username", "password", $options);} catch (Exception $e) { error_log($e->getMessage()); exit('Something weird happened'); //something a user can understand}
MySQLi
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);try { $mysqli = new mysqli("localhost", "username", "password", "databaseName"); $mysqli->set_charset("utf8mb4");} catch(Exception $e) { error_log($e->getMessage()); exit('Error connecting to database'); //Should be a message a typical user could understand}
插入、更新、刪除
PDO
$stmt = $pdo->prepare("INSERT INTO myTable (name, age) VALUES (?, ?)"); $stmt->execute([$_POST['name'], 29]); $stmt = null;
MySQLi
$stmt = $mysqli->prepare("UPDATE myTable SET name = ? WHERE id = ?"); $stmt->bind_param("si", $_POST['name'], $_SESSION['id']); $stmt->execute(); $stmt->close();
注意,使用PDO可以將prepare()和execute()鏈接起來。
獲取受影響的行數
PDO
$stmt->rowCount();
MySQLi
$stmt->affected_rows;
插入最新的主鍵
注意,這兩種方法都使用connection變量,而不是$stmt。
PDO
$pdo->lastInsertId();
MySQLi
$mysqli->insert_id;
得到匹配的行
PDO
在PDO中,實現這一點的唯一方法是將其設置為一個連接選項,以更改rowCount()的行為。這意味著rowCount()將為整個數據庫連接返回匹配的行或更改的行,但不能同時返回兩者。
$options = [ PDO::MYSQL_ATTR_FOUND_ROWS => true];
MySQLi
$mysqli->info;
這將輸出整個字符串的信息,如:
Rows matched: 1 Changed: 0 Warnings: 0
可以這樣做
preg_match_all('/(\S[^:]+): (\d+)/', $mysqli->info, $matches); $infoArr = array_combine ($matches[1], $matches[2]); var_export($infoArr);
現在可以很容易地訪問這些值。注意,該值是一個字符串,因此你可以將所有值轉換為int,===可以使用,也可以嚴格檢查==。
['Rows matched' => '1', 'Changed' => '0', 'Warnings' => '0']
抓取
獲取關聯數組
PDO
$stmt = $pdo->prepare("SELECT * FROM myTable WHERE id <= ?"); $stmt->execute([5]); $arr = $stmt->fetchAll(PDO::FETCH_ASSOC); if(!$arr) exit('No rows'); var_export($arr); $stmt = null;
MySQLi
$stmt = $mysqli->prepare("SELECT id, name, age FROM myTable WHERE name = ?"); $stmt->bind_param("s", $_POST['name']); $stmt->execute(); $arr = $stmt->get_result()->fetch_all(MYSQLI_ASSOC); if(!$arr) exit('No rows'); var_export($arr); $stmt->close();
獲取單行
PDO
$stmt = $pdo->prepare("SELECT id, name, age FROM myTable WHERE name = ?"); $stmt->execute([$_POST['name']]); $arr = $stmt->fetch(PDO::FETCH_ASSOC); if(!$arr) exit('No rows'); var_export($arr); $stmt = null;
MySQLi
$stmt = $mysqli->prepare("SELECT id, name, age FROM myTable WHERE name = ?"); $stmt->bind_param("s", $_POST['name']); $stmt->execute(); $arr = $stmt->get_result()->fetch_assoc(); if(!$arr) exit('No rows'); var_export($arr); $stmt->close();
獲取單個值(標量)
PDO
$stmt = $pdo->prepare("SELECT id, name, age FROM myTable WHERE name = ?"); $stmt->execute([$_POST['name']]); $arr = $stmt->fetch(PDO::FETCH_COLUMN); if(!$arr) exit('No rows'); var_export($arr); $stmt = null;
MySQLi
$stmt = $mysqli->prepare("SELECT id, name, age FROM myTable WHERE name = ?"); $stmt->bind_param("s", $_POST['name']); $stmt->execute(); $arr = $stmt->get_result()->fetch_row()[0]; if(!$arr) exit('No rows'); var_export($arr); $stmt->close();
獲取對象數組
PDO
class myClass {} $stmt = $pdo->prepare("SELECT name, age, weight FROM myTable WHERE name = ?"); $stmt->execute(['Joe']); $arr = $stmt->fetchAll(PDO::FETCH_CLASS, 'myClass'); if(!$arr) exit('No rows'); var_export($arr); $stmt = null;
MySQLi
class myClass {} $arr = []; $stmt = $mysqli->prepare("SELECT id, name, age FROM myTable WHERE id = ?"); $stmt->bind_param("s", $_SESSION['id']); $stmt->execute(); $result = $stmt->get_result(); while($row = $result->fetch_object('myClass')) { $arr[] = $row; } if(!$arr) exit('No rows'); var_export($arr); $stmt->close();
正如你所看到的,PDO在這里非常出色。MySQLi沒有像$mysqli_result->fetch_all(MYSQLI_OBJ)這樣的東西。PDO甚至更進一步,通過使用fetchAll(PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE, 'myClass')對它進行位元化,以處理在類構造函數之后調用它的默認行為??梢栽贛ySQLi中復制這種行為,但是它依賴于省略構造函數,和魔術方法 _set(),或者只在構造函數中設置它(如果它不等于默認值)。
PDO
$search = "%{$_POST['search']}%"; $stmt = $pdo->prepare("SELECT id, name, age FROM myTable WHERE name LIKE ?"); $stmt->execute([$search]); $arr = $stmt->fetchAll(); if(!$arr) exit('No rows'); var_export($arr); $stmt = null; Copy
MySQLi
$search = "%{$_POST['search']}%"; $stmt = $mysqli->prepare("SELECT id, name, age FROM myTable WHERE name LIKE ?"); $stmt->bind_param("s", $search); $stmt->execute(); $arr = $stmt->get_result()->fetch_all(MYSQLI_ASSOC); if(!$arr) exit('No rows'); var_export($arr); $stmt->close();
獲取模式
到目前為止,這是我最喜歡的PDO特性。PDO中的獲取模式非常有用,而MySQLi還沒有添加它們。
獲取鍵/值對
PDO
$stmt = $pdo->prepare("SELECT event_name, location FROM events WHERE id < ?"); $stmt->execute([25]); $arr = $stmt->fetchAll(PDO::FETCH_KEY_PAIR); if(!$arr) exit('No rows'); var_export($arr); $stmt = null; Copy
MySQLi
$arr = []; $id = 25; $stmt = $con->prepare("SELECT event_name, location FROM events WHERE id < ?"); $stmt->bind_param("i", $id); $stmt->execute(); $result = $stmt->get_result(); while($row = $result->fetch_row()) { $arr[$row[0]] = $row[1]; } if(!$arr) exit('No rows'); var_export($arr); $stmt->close();
輸出:
['Cool Event' => 'Seattle', 'Fun Event' => 'Dallas', 'Boring Event' => 'Chicago']
獲取組列
PDO
$stmt = $pdo->prepare("SELECT hair_color, name FROM myTable WHERE id < ?"); $stmt->execute([10]); $arr = $stmt->fetchAll(PDO::FETCH_GROUP | PDO::FETCH_COLUMN); if(!$arr) exit('No rows'); var_export($arr); $stmt = null; Copy
MySQLi
$arr = []; $id = 10; $stmt = $con->prepare("SELECT hair_color, name FROM myTable WHERE id < ?"); $stmt->bind_param("i", $id); $stmt->execute(); $result = $stmt->get_result(); while($row = $result->fetch_row()) { $arr[$row[0]][] = $row[1]; } if(!$arr) exit('No rows'); var_export($arr); $stmt->close(); Copy
輸出:
[ 'blonde' => ['Patrick', 'Olivia'], 'brunette' => ['Kyle', 'Ricky'], 'red' => ['Jordan', 'Eric'] ]
獲取鍵/值對數組
PDO
$stmt = $pdo->prepare("SELECT id, max_bench, max_squat FROM myTable WHERE weight < ?"); $stmt->execute([200]); $arr = $stmt->fetchAll(PDO::FETCH_UNIQUE); if(!$arr) exit('No rows'); var_export($arr); $stmt = null; Copy
MySQLi
$arr = []; $weight = 200; $stmt = $con->prepare("SELECT id, max_bench, max_squat FROM myTable WHERE weight < ?"); $stmt->bind_param("i", $weight); $stmt->execute(); $result = $stmt->get_result(); $firstColName = $result->fetch_field_direct(0)->name; while($row = $stmtResult->fetch_assoc()) { $firstColVal = $row[$firstColName]; unset($row[$firstColName]); $arr[$firstColVal] = $row; } if(!$arr) exit('No rows'); var_export($arr); $stmt->close(); Copy
輸出:
[ 17 => ['max_bench' => 230, 'max_squat' => 175], 84 => ['max_bench' => 195, 'max_squat' => 235], 136 => ['max_bench' => 135, 'max_squat' => 285] ]
獲取組
PDO
$stmt = $pdo->prepare("SELECT hair_color, name, age FROM myTable WHERE id < ?"); $stmt->execute([12]); $arr = $stmt->fetchAll(PDO::FETCH_GROUP); if(!$arr) exit('No rows'); var_export($arr); $stmt = null; Copy
MySQLi
$arr = []; $id = 12; $stmt = $con->prepare("SELECT hair_color, name, age FROM myTable WHERE id < ?"); $stmt->bind_param("i", $id); $stmt->execute(); $result = $stmt->get_result(); $firstColName = $result->fetch_field_direct(0)->name; while($row = $stmtResult->fetch_assoc()) { $firstColVal = $row[$firstColName]; unset($row[$firstColName]); $arr[$firstColVal][] = $row; } if(!$arr) exit('No rows'); var_export($arr); $stmt->close(); Copy
輸出:
[ 'blonde' => [ ['name' => 'Patrick', 'age' => 22], ['name' => 'Olivia', 'age' => 18] ], 'brunette' => [ ['name' => 'Kyle', 'age'=> 25], ['name' => 'Ricky', 'age' => 34] ], 'red' => [ ['name' => 'Jordan', 'age' => 17], ['name' => 'Eric', 'age' => 52] ] ]
在數組中的位置
PDO
$inArr = [1, 3, 5]; $clause = implode(',', array_fill(0, count($inArr), '?')); $stmt = $pdo->prepare("SELECT * FROM myTable WHERE id IN ($clause)"); $stmt->execute($inArr); $resArr = $stmt->fetchAll(); if(!$resArr) exit('No rows'); var_export($resArr); $stmt = null; Copy
MySQLi
$inArr = [12, 23, 44]; $clause = implode(',', array_fill(0, count($inArr), '?')); / $types = str_repeat('i', count($inArr)); / $stmt = $mysqli->prepare("SELECT id, name FROM myTable WHERE id IN ($clause)"); $stmt->bind_param($types, ...$inArr); $stmt->execute(); $resArr = $stmt->get_result()->fetch_all(MYSQLI_ASSOC); if(!$resArr) exit('No rows'); var_export($resArr); $stmt->close();
與其他占位符一起排列的位置
PDO
$inArr = [1, 3, 5]; $clause = implode(',', array_fill(0, count($inArr), '?')); $stmt = $pdo->prepare("SELECT * FROM myTable WHERE id IN ($clause) AND id < ?"); $fullArr = array_merge($inArr, [5]); $stmt->execute($fullArr); $resArr = $stmt->fetchAll(); if(!$resArr) exit('No rows'); var_export($resArr); $stmt = null; Copy
MySQLi
$inArr = [12, 23, 44]; $clause = implode(',', array_fill(0, count($inArr), '?')); $types = str_repeat('i', count($inArr)); $types .= 'i'; //add 1 more int type $fullArr = array_merge($inArr, [26]); $stmt = $mysqli->prepare("SELECT id, name FROM myTable WHERE id IN ($clause) AND age > ?"); $stmt->bind_param($types, ...$fullArr); $stmt->execute(); $resArr = $stmt->get_result()->fetch_all(MYSQLI_ASSOC); if(!$resArr) exit('No rows'); var_export($resArr); $stmt->close();
交易
PDO
try { $pdo->beginTransaction(); $stmt1 = $pdo->prepare("INSERT INTO myTable (name, state) VALUES (?, ?)"); $stmt2 = $pdo->prepare("UPDATE myTable SET age = ? WHERE id = ?"); if(!$stmt1->execute(['Rick', 'NY'])) throw new Exception('Stmt 1 Failed'); else if(!$stmt2->execute([27, 139])) throw new Exception('Stmt 2 Failed'); $stmt1 = null; $stmt2 = null; $pdo->commit(); } catch(Exception $e) { $pdo->rollback(); throw $e; }
MySQLi
try { $mysqli->autocommit(FALSE); $stmt1 = $mysqli->prepare("INSERT INTO myTable (name, age) VALUES (?, ?)"); $stmt2 = $mysqli->prepare("UPDATE myTable SET name = ? WHERE id = ?"); $stmt1->bind_param("si", $_POST['name'], $_POST['age']); $stmt2->bind_param("si", $_POST['name'], $_SESSION['id']); $stmt1->execute(); $stmt2->execute(); $stmt1->close(); $stmt2->close(); $mysqli->autocommit(TRUE); } catch(Exception $e) { $mysqli->rollback(); throw $e; }
MySQLi有一個問題,但是解決方案是使用全局處理程序將錯誤轉換為異常。
命名為Paramters
$stmt = $pdo->prepare("UPDATE myTable SET name = :name WHERE id = :id"); $stmt->execute([':name' => 'David', ':id' => 3]); $stmt = null;
對于以上關于PDO與MySQLi各自優勢及該如何選擇,大家是不是覺得非常有幫助。如果需要了解更多內容,請繼續關注我們的行業資訊,相信你會喜歡上這些內容的。
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