PHP 创建 MySQL 表

一个数据表有一个唯一名称,并有行和列组成。

使用 MySQLi 和 PDO 创建 MySQL 表

CREATE TABLE 语句用于创建 MySQL 表。

我们将创建一个名为 "MyGuests" 的表,有 5 个列: "id", "firstname", "lastname", "email" 和 "reg_date":

CREATE TABLE MyGuests (  
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,  
firstname VARCHAR(30) NOT NULL,  
lastname VARCHAR(30) NOT NULL,  
email VARCHAR(50),  
reg_date TIMESTAMP  
)

上表中的注意事项:

数据类型指定列可以存储什么类型的数据。完整的数据类型请参考我们的 数据类型参考手册

在设置了数据类型后,你可以为没个列指定其他选项的属性:

  • NOT NULL - 没一行都必须含有值(不能为空),null 值是不允许的。
  • DEFAULT value - 设置默认值
  • UNSIGNED - 使用无符号数值类型,0 及正数
  • AUTO INCREMENT - 设置 MySQL 字段的值在新增记录时每次自动增长 1
  • PRIMARY KEY - 设置数据表中每条记录的唯一标识。 通常列的 PRIMARY KEY 设置为 ID 数值,与 AUTO_INCREMENT 一起使用。

每个表都应该有一个主键(本列为 "id" 列),主键必须包含唯一的值。

以下实例展示了如何在 PHP 中创建表:

实例 (MySQLi - 面向对象)

<?php  
$servername = "localhost";  
$username = "username";  
$password = "password";  
$dbname = "myDB";  

// 创建连接  
$conn = new mysqli($servername, $username, $password, $dbname);  
// 检测连接  
if ($conn->connect_error) {  
    die("Connection failed: " . $conn->connect_error);  
}  

// sql to create table  
$sql = "CREATE TABLE MyGuests (  
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,  
firstname VARCHAR(30) NOT NULL,  
lastname VARCHAR(30) NOT NULL,  
email VARCHAR(50),  
reg_date TIMESTAMP  
)";  

if ($conn->query($sql) === TRUE) {  
    echo "Table MyGuests created successfully";  
} else {  
    echo "Error creating table: " . $conn->error;  
}  

$conn->close();  
?>

实例 (MySQLi - 面向过程)

<?php  
$servername = "localhost";  
$username = "username";  
$password = "password";  
$dbname = "myDB";  

// 创建连接  
$conn = mysqli_connect($servername, $username, $password, $dbname);  
// 检测连接  
if (!$conn) {  
    die("Connection failed: " . mysqli_connect_error());  
}  

// sql to create table  
$sql = "CREATE TABLE MyGuests (  
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,  
firstname VARCHAR(30) NOT NULL,  
lastname VARCHAR(30) NOT NULL,  
email VARCHAR(50),  
reg_date TIMESTAMP  
)";  

if (mysqli_query($conn, $sql)) {  
    echo "Table MyGuests created successfully";  
} else {  
    echo "Error creating table: " . mysqli_error($conn);  
}  

mysqli_close($conn);  
?>

实例 (PDO)

<?php  
$servername = "localhost";  
$username = "username";  
$password = "password";  
$dbname = "myDBPDO";  

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);  

    // sql to create table  
    $sql = "CREATE TABLE MyGuests (  
    id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,  
    firstname VARCHAR(30) NOT NULL,  
    lastname VARCHAR(30) NOT NULL,  
    email VARCHAR(50),  
    reg_date TIMESTAMP  
    )";  

    // use exec() because no results are returned  
    $conn->exec($sql);  
    echo "Table MyGuests created successfully";  
    }  
catch(PDOException $e)  
    {  
    echo $sql . "<br>" . $e->getMessage();  
    }  

$conn = null;  
?>