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。
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;
?>