What are the methods to connect to the database in PHP7

This article will introduce to you how to connect to the database in PHP7. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

The methods to use native PHP to connect to MySQL include the MySQL library, MySQLi library and PDO. Since PHP 7 has abolished the MySQL library, it is recommended to use MySQLi and PDO.

There are two styles for connecting to MySQLi:

• Object-oriented style (recommended)

• Procedural style

Object-oriented style:

<?php
$mysqli = new mysqli(&#39;localhost&#39;, &#39;root&#39;, &#39;123456&#39;, &#39;test_laravel&#39;);
if ($mysqli->connect_error) {
   die(&#39;Connect Error (&#39; . $mysqli->connect_errno . &#39;) &#39; . $mysqli->connect_error);
}
$result = $mysqli->query(&#39;select * from articles&#39;);
$row = $result->fetch_array(MYSQLI_ASSOC);
print_r($row);
// 关闭mysql连接
$mysqli->close();

Run:

Array
(
    [id] => 1
    [title] => My new title
    [body] => First Body
    [created_at] => 2017-05-22 11:10:20
    [updated_at] => 2017-05-22 11:30:58
    [published_at] => 2017-05-22 11:10:00
    [excerpt] =>
)

If the fetch_array method does not take parameters, the default is MYSQLI _BOTH, and the output is like this:

(
[0] => 1
[id] => 1
[1] => My new title
 [title] => My new title
[2] => First Body
[body] => First Body
[3] => 2017-05-22 11:10:20
[created_at] => 2017-05-22 11:10:20
[4] => 2017-05-22 11:30:58
[updated_at] => 2017-05-22 11:30:58
[5] => 2017-05-22 11:10:00
[published_at] => 2017-05-22 11:10:00
[6] =>
 [excerpt] =>
)

You can also choose MYSQLI _NUM

Array
(
    [0] => 1
    [1] => My new title
    [2] => First Body
    [3] => 2017-05-22 11:10:20
    [4] => 2017-05-22 11:30:58
    [5] => 2017-05-22 11:10:00
    [6] =>
)

Generally speaking, choose MySQLI _ASSOC

for the procedural style:

<?php
$mysqli = mysqli_connect(&#39;localhost&#39;, &#39;root&#39;, &#39;123456&#39;, &#39;test_laravel&#39;);
if (mysqli_connect_error()) {
    die(&#39;Connect Error (&#39; . $mysqli->connect_errno . &#39;) &#39; . $mysqli->connect_error);
}
$result = mysqli_query($mysqli, &#39;select * from articles&#39;);
$row = mysqli_fetch_array($result, MYSQLI_ASSOC);
print_r($row);
// 关闭mysql连接
mysqli_close($mysqli);

The operation is the same as above.

Use PDO to connect to mysql:

<?php

try {
    $PDO = new PDO(&#39;mysql:host=localhost;dbname=test_laravel&#39;, &#39;root&#39;, &#39;123456&#39;);
    $result = $PDO->query(&#39;select * from articles&#39;);
    $row = $result->fetch(PDO::FETCH_ASSOC);
    print_r($row);

    // 关闭mysqi连接
    $PDO = null;
} catch (PDOException $e) {
    die(&#39;Connection failed: &#39; . $e->getMessage());
}

If the fetch method of PDO does not take parameters, the default is: PDO::FETCH_BOTH, or PDO::FETCH_NUM and PDO::FETCH_ASSOC, etc., generally It says to select PDO::FETCH_ASSOC.

Summary: You can use PDO or MySQLi, but it is more recommended to use PDO to connect to the database on the Internet. This is because PDO supports 12 different database drivers, while MySQLi can only support MySQL. In addition, PDO The performance is also higher.

Recommended learning: php video tutorial

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