PHP develops simple guestbook to create database and table

First create a database "test" in mysql, and then create a database table "ly" in the database.

Create a test database first:

<?php
// 创建连接
$conn = new mysqli("localhost", "uesename", "password");
// 检测连接
if ($conn->connect_error) 
{    
    die("连接失败: " . $conn->connect_error);} 
    // 创建数据库
    $sql = "CREATE DATABASE test";
        if ($conn->query($sql) === TRUE) 
        {    
        echo "数据库创建成功";
        } else {    
        echo "Error creating database: " . $conn->error;
        }
    $conn->close();
?>

Set the following fields:

id: It is unique, type is int, and select the primary key.

nackname: User nickname, type is varchar, length is 30.

message: message content, type is text. Although the text type field also belongs to a character type, its size cannot be specified.

lytime: The message content release time, the type is datetime, no need to set the length.

reply: The content of the reply message, type is text.

retime: The time to reply to the message, the type is datetime, no need to set the length.

SQL statement to create a database table:

<?php
$SQL = " CREATE TABLE IF NOT EXISTS `ly` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `nickname` varchar(30) CHARACTER SET utf8 NOT NULL,
   `message` text CHARACTER SET utf8 NOT NULL,
  `avatar` varchar(50) CHARACTER SET utf8 NOT NULL,
  `lytime` datetime NOT NULL,
   `reply` text CHARACTER SET utf8 NOT NULL,
  `retime` datetime NOT NULL,
   PRIMARY KEY (`id`),
   UNIQUE KEY `id` (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ";
?>

In this way, we have completed the creation of the database table.