The choice of database in PHP means choosing a database management system that suits your project needs. Different database management systems have different characteristics and applicable scenarios. In PHP, our common database management systems include MySQL, SQLite, PostgreSQL, etc., each of which has its own advantages and disadvantages. When selecting a database, you need to make an appropriate choice based on factors such as project needs, data volume, and performance requirements.
1. MySQL: MySQL is currently the most popular open source relational database management system. It has the characteristics of excellent performance, ease of use, and wide support. In PHP, the code examples using MySQL are as follows:
<?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "dbname"; // 创建连接 $conn = mysqli_connect($servername, $username, $password, $dbname); // 检测连接 if (!$conn) { die("Connection failed: " . mysqli_connect_error()); } // 查询数据 $sql = "SELECT id, name, email FROM users"; $result = mysqli_query($conn, $sql); if (mysqli_num_rows($result) > 0) { // 输出数据 while($row = mysqli_fetch_assoc($result)) { echo "id: " . $row["id"]. " - Name: " . $row["name"]. " - Email: " . $row["email"]. "<br>"; } } else { echo "0 results"; } // 关闭连接 mysqli_close($conn); ?>
2. SQLite: SQLite is a lightweight embedded database management system. It is a zero-configuration, serverless database engine, suitable for small app or mobile app. In PHP, code examples using SQLite are as follows:
<?php $db = new SQLite3('test.db'); // 查询数据 $results = $db->query('SELECT * FROM users'); while ($row = $results->fetchArray()) { var_dump($row); } // 关闭连接 $db->close(); ?>
3. PostgreSQL: PostgreSQL is a powerful open source object-relational database management system with high scalability and security. In PHP, code examples for using PostgreSQL are as follows:
<?php $dbconn = pg_connect("host=localhost dbname=dbname user=username password=password"); // 查询数据 $result = pg_query($dbconn, "SELECT id, name, email FROM users"); if (!$result) { echo "Query failed."; exit; } while ($row = pg_fetch_row($result)) { echo "id: $row[0] - Name: $row[1] - Email: $row[2]<br>"; } // 关闭连接 pg_close($dbconn); ?>
The above are code examples for using three common database management systems: MySQL, SQLite, and PostgreSQL in PHP. It is very important to choose a suitable database according to the project needs and characteristics. important. Hope the above content can be helpful to you.
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