在 php 中建立数据库共有 8 个步骤：建立连接、创建数据库、创建表、插入数据、查询数据、更新数据、删除数据和关闭连接。

如何使用 PHP 建立数据库

步骤 1：建立连接

$servername = "localhost";
$username = "root";
$password = "password";
$conn = new PDO("mysql:host=$servername;dbname=db_name", $username, $password);

步骤 2：创建数据库

$sql = "CREATE DATABASE db_name";
$conn->query($sql);

步骤 3：创建表

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$sql = "CREATE TABLE table_name (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(30) NOT NULL,
age INT(3) UNSIGNED NOT NULL
)";
$conn->query($sql);

步骤 4：插入数据

$sql = "INSERT INTO table_name (name, age) VALUES (?, ?)";
$stmt = $conn->prepare($sql);
$stmt->bind_param("ss", $name, $age);
$name = "John Doe";
$age = 30;
$stmt->execute();

步骤 5：查询数据

$sql = "SELECT * FROM table_name";
$stmt = $conn->query($sql);
while ($row = $stmt->fetch_assoc()) {
    echo $row['name'] . '<br>';
}

步骤 6：更新数据

$sql = "UPDATE table_name SET name = ? WHERE id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("si", $name, $id);
$name = "John Smith";
$id = 1;
$stmt->execute();

步骤 7：删除数据

$sql = "DELETE FROM table_name WHERE id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $id);
$id = 1;
$stmt->execute();

步骤 8：关闭连接

$conn->close();