In fact, there is no desire today..-MySQLi, desire..-MySQLi_PHP Tutorial

In fact, I have no desire today..-MySQLi, desire..-MySQLi

　hi

I had a refreshing swim at noon, but after finishing reading One Punch Man in the afternoon, I no longer had the desire to learn. . . Force yourself to update something and read a book later.

1. MySQLi

2. MySQLi OOP-based programming

2.1 Using parsing

--Basic

MySQLi is an extended class library, essentially a class (?).

The general process is the same as MySQL: connection, library selection, character set setting, SQL statement execution, closing connection .

--Link library example

/*
* Connect and select database
*/
$mysqli=new mysqli('localhost', 'root' , '');
print_r($mysqli);echo "
";

echo $mysqli->select_db('test');echo "
";

$mysqli2=new mysqli();
print_r($mysqli2->connect('localhost', 'root', ''));echo "
";

print_r($mysqli3=new mysqli('localhost', 'root', '','test'));echo "
";

Three different methods, the methods here are all done using the class attributes of mysqli; of course, you can also use mysqli commands to link;

$con=mysqli_connect(HOST,USERNAME,PASSWORD)

There is some information in the results

These attributes can be obtained through the attributes of the object, such as

echo $mysqli->client_info;echo "
";

Or it can be obtained through corresponding methods. You can see these things in the manual.

header('content-type:text/html;charset=utf-8');
//1. Establish a connection to MySQL data
// $mysqli= new mysqli('localhost','root','root');
// //print_r($mysqli);
// //2. Open the specified database
// $mysqli- >select_db('test');
// $mysqli=new mysqli();
// $mysqli->connect('127.0.0.1','root','root');
// print_r($mysqli);

//Open the specified database while establishing a connection
$mysqli=@new mysqli('localhost','root','root','test');
//print_r($mysqli);
//$mysqli->connect_errno: Get the error number generated by the connection
//$mysqli->connect_error: Get the error message generated by the connection
if($mysqli->connect_errno){
die('Connect Error:'.$mysqli->connect_error);
}
print_r($mysqli);
echo '

echo '

--Character set example

//1. Establish a connection to MySQL
$mysqli=@new mysqli('localhost','root','root','test');
if ($mysqli->connect_errno){
die('Connect Error:'.$mysqli->connect_error);
}
//2. Set the default client encoding utf8
$mysqli->set_charset('utf8');

///3. Execute SQL query
$sql=<< CREATE TABLE IF NOT EXISTS mysqli(
id TINYINT UNSIGNED AUTO_INCREMENT KEY,
username VARCHAR(20) NOT NULL
);
EOF;
$res=$mysqli->query($sql);
var_dump($res);

/*
SELECT/DESC/DESCRIBE/SHOW/EXPLAIN returns the mysqli_result object if the execution is successful, and false if the execution fails
For the execution of other SQL statements, true is returned if the execution is successful, otherwise false
*/
//Close the connection
$mysqli->close();

It should be noted that the database is utf8, not utf-8;

2.2 Insert record operation

Increase.

--connect.php

Because a series of operations to connect to the database are commonly used, for this, our simple method is to encapsulate it and call

require_once 'connect.php';

connect.php

/*
* Connection and library selection (header) files
*/
$mysqli=new mysqli('localhost', 'root ', '','test');
if($mysqli->connect_errno){
die('Connect Error:'.$mysqli->connect_error);
}else{
echo 'Client information:'.$mysqli->client_info.'
';
}
$mysqli->set_charset('utf8');

--Added

/*
* Insert data into database
*/

require_once 'connect.php';

$sql="insert mysqli(username) value('Tom')";
echo $mysqli->query($sql);