How to use PHP7.0 for database operations?

In recent years, PHP has become a popular server-side programming language, often used to build web applications and also to interact with databases. As one of the most popular relational databases, MySQL is the best choice for PHP to interact with. PHP7.0 has brought many optimizations and improvements. How to use PHP for database operations in this version? This article will introduce in detail how to use PHP7.0 for database operations.

1. Install PHP7.0 and MySQL

Before using PHP7.0 for database operations, we need to install PHP7.0 and MySQL first. Under the Ubuntu system, you can install it through the following instructions:

sudo apt-get update
sudo apt-get install php7.0 mysql-server-5.7

where php7.0 is The installation package of PHP7.0, mysql-server-5.7 is the installation package of MySQL.

2. Connecting to the database

Connecting to the database is the first step to perform database operations. In PHP, you can use the mysqli extension and PDO extension for database operations. This article will use the PDO extension to operate.

Through PDO extension, you can easily interact with a variety of databases and will not be restricted by specific databases. Next, we will connect to the MySQL database.

$host = 'localhost';
$db_name = 'my_database';
$username = 'my_username';
$password = 'my_password';

try {

$pdo = new PDO("mysql:host=$host;dbname=$db_name", $username, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
echo "Connected successfully";

} catch(PDOException $e) {

echo "Connection failed: " . $e->getMessage();

}

In the above code, we create a PDO object and Store it in the variable $pdo. Among them, $host is the database server name, $db_name is the database name, $username and $password are the credentials used to connect to the database. If the connection is successful, "Connected successfully" will be output, otherwise an error message will be output.

3. Query data

After the connection is successful, we can query. Here is a simple query example:

$stmt = $pdo->prepare("SELECT * FROM users");
$stmt->execute() ;
$result = $stmt->fetchAll();

foreach($result as $row) {

echo $row['id'] . " " . $row['name'] . " " . $row['email'] . "

";
}

In the above code, we use the prepare() method to prepare the query statement, then use the execute() method to execute the query, and finally use the fetchAll() method to obtain the query results and store them in the $result variable. Through the foreach loop, we will The query results are output to the console.

4. Insert data

In addition to querying data, we can also use PDO extension to insert data into the database. The following is a simple insert Data example:

$name = "John";
$email = "john@example.com";

$stmt = $pdo-> ;prepare("INSERT INTO users (name, email) VALUES (?, ?)");
$stmt->execute([$name, $email]);

echo "Data inserted successfully";

In the above code, we use the prepare() method to prepare the insertion statement and replace the placeholder with a variable. Then use the execute() method to perform the insertion operation.

Except Using placeholders, the PDO extension also supports the use of named parameters. Here is an example of inserting data using named parameters:

$name = "John";
$email = "john@example.com";

$stmt = $pdo->prepare("INSERT INTO users (name, email) VALUES (:name, :email)");
$stmt- >execute(['name' => $name, 'email' => $email]);

echo "Data inserted successfully";

In the above code, we Use a colon plus the parameter name to specify the parameter name, and then pass the variable to the execute() method as an associative array.

5. Update and delete data

In addition to inserting data, we can also use PDO extensions to update and delete data. Here is an example of updating data:

$id = 1;
$email = "john@example.com";

$stmt = $pdo ->prepare("UPDATE users SET email = ? WHERE id = ?");
$stmt->execute([$email, $id]);

echo "Data updated successfully" ;

In the above code, we use the prepare() method to prepare the update statement, replacing the placeholders with variables. Update operations are performed through the execute() method.

The following is an example of deleting data:

$id = 1;

$stmt = $pdo->prepare("DELETE FROM users WHERE id = ?");
$stmt->execute([$id]);

echo "Data deleted successfully";

In the above code, we use prepare() method to prepare the delete statement, replacing placeholders with variables. The delete operation is performed through the execute() method.

6. Summary

Through this article, we learned how to use PDO extensions to perform database operations, including connecting to the database, querying data, inserting data, updating data and deleting data. By using PDO extensions, we can easily interact with a variety of databases and are not restricted to a specific database. Using PHP7.0 for database operations is a very valuable skill. I hope this article can inspire you.

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