PHP MySQL ma’lumot tanlash (SELECT)
MySQL ma’lumotlar bazasidan ma’lumotlarni tanlang
SQL SELECT buyrug‘i jadvaldan ma’lumotlarni tanlash uchun ishlatiladi.
Jadvaldan ma’lum ustunlarni tanlash uchun quyidagilardan foydalaning:
SELECT column1, column2, column3 FROM table_name
Jadvaldan HAMMA ustunlarni tanlash uchun * belgisidan foydalaning:
SELECT * FROM table_name
SQL haqida ko‘proq ma’lumot olish uchun bizning SQL qo‘llanmamizga tashrif buyuring.
MySQLi bilan ma’lumotlarni tanlang
Quyidagi misol MyGuests jadvalidan identifikator, ism va familiya ustunlarini tanlaydi va uni sahifada ko‘rsatadi:
Misol - MySQLi obyektga yo‘naltirilgan
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT id, firstname, lastname FROM MyGuests";
// Execute the SQL query
$result = $conn->query($sql);
// Process the result set
if ($result->num_rows > 0) {
// Output data of each row
while($row = $result->fetch_assoc()) {
echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
}
} else {
echo "0 results";
}
$conn->close();
?>
Misolni ishga tushirish »
Kod tushuntirish
Birinchidan, MyGuests jadvalidan id, ism va familiya ustunlarini tanlaydigan SQL so‘rovini o‘rnatamiz.
Keyingi kod satri $conn->query($sql) so‘rovni ishga tushiradi va olingan ma’lumotlarni $result deb nomlangan o‘zgaruvchiga joylashtiradi.
Keyin $result->num_rows>0 qatori qaytarilgan 0 dan ortiq qator mavjudligini tekshiradi.
Agar 0 dan ortiq satr qaytarilsa, fetch_assoc() funksiyasi natijalar to‘plamini biz aylanib o‘tishimiz mumkin bo‘lgan assotsiativ massivga joylashtiradi. while() sikli natijalar to‘plami bo‘ylab o‘tadi va id, firstname va lastname ustunlaridan ma’lumotlarni chiqaradi.
Quyidagi misol MySQLi-da yuqoridagi misol bilan bir xil narsani ko‘rsatadi protsessual metod:
Misol - MySQLi protsessual
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
$sql = "SELECT id, firstname, lastname FROM MyGuests";
// Execute the SQL query
$result = mysqli_query($conn, $sql);
// Process the result set
if (mysqli_num_rows($result) > 0) {
// Output data of each row
while($row = mysqli_fetch_assoc($result)) {
echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
}
} else {
echo "0 results";
}
mysqli_close($conn);
?>
Misolni ishga tushirish »
Natijani HTML jadvaliga qo‘ying
Bu yerda biz natijani HTML jadvaliga joylashtiramiz:
Misol - MySQLi obyektga yo‘naltirilgan
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT id, firstname, lastname FROM MyGuests";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
echo "<table><tr><th>ID</th><th>Name</th></tr>";
// output data of each row
while($row = $result->fetch_assoc()) {
echo "<tr><td>".$row["id"]."</td><td>".$row["firstname"]." ".$row["lastname"]."</td></tr>";
}
echo "</table>";
} else {
echo "0 results";
}
$conn->close();
?>
Misolni ishga tushirish »
PDO bilan ma’lumotlarni tanlang
Quyidagi misol MyGuests jadvalidan identifikator, ism va familiya ustunlarini tanlaydi va uni HTML jadvalida ko‘rsatadi:
Misol - PDO
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
try {
$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
// set the PDO error mode to exception
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch(PDOException $e){
die("Could not connect. " . $e->getMessage());
}
try {
$sql = "SELECT id, firstname, lastname FROM MyGuests";
// Execute the SQL query
$result = $conn->query($sql);
// Process the result set
if ($result->rowCount() > 0) {
echo "<table><tr><th>ID</th><th>Firstname</th><th>Lastname</th></tr>";
// Output data of each row
while($row = $result->fetch()) {
echo "<tr>";
echo "<td>" . $row['id'] . "</td>";
echo "<td>" . $row['firstname'] . "</td>";
echo "<td>" . $row['lastname'] . "</td>";
echo "</tr>";
}
echo "</table>";
unset($result);
} else {
echo "No records found.";
}
} catch(PDOException $e) {
echo "Error: " . $e->getMessage();
}
$conn = null;
?>
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