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In modern Internet applications, adding data is a very common task. PHP is a popular web development language that comes with many easy-to-use tools and features that help developers with the task of adding data. This article will introduce the main steps and related tools for adding data in PHP.
1. Connect to the database
In PHP, the first step to add data is to connect to the database. To connect to a database, you need to provide information such as the name of the database, host address, username, and password.
1.1 Use the mysql_connect() function to connect to the database
In PHP, you can use the mysql_connect() function to connect to the MySQL database. The syntax for connecting to the database is as follows:
$con = mysql_connect("host","username","password"); if (!$con) { die('Could not connect to database: ' . mysql_error()); } $db_selected = mysql_select_db("database_name",$con); if (!$db_selected) { die('Could not select database: ' . mysql_error()); }
Among them, $con is the connection object, that is, the state after connecting to the database. If the connection fails, an error message appears. $db_selected is the selected database name.
1.2 Use the mysqli_connect() function to connect to the database
mysqli is an improved version of the MySQL extension in PHP, providing higher performance and object-oriented support. To connect to a MySQL database using mysqli, you can use the following syntax:
$con = mysqli_connect("host","username","password","database_name"); if (!$con) { die('Could not connect to database: ' . mysqli_connect_errno()); }
1.3 Use PDO to connect to the database
PDO (PHP Data Object) is an extension of PHP that provides a consistent interface. for connecting to different types of database systems. To use PDO to connect to a MySQL database, you can use the following example:
$dsn = 'mysql:host=host;dbname=database_name'; $user = 'username'; $password = 'password'; try { $con = new PDO($dsn, $user, $password); } catch (PDOException $e) { die('Could not connect to database: ' . $e->getMessage()); }
2. Write data
After connecting to the database, you can start writing data to the database. In PHP, you can use the following methods to write data to the database:
2.1 Use the mysql_query() function to write data
The mysql_query() function is the most basic method to write data to the MySQL database . It uses the following syntax:
mysql_query("INSERT INTO table_name (column1, column2, column3) VALUES ('value1', 'value2', 'value3')");
Among them, INSERT INTO is part of the SQL statement and points to the table where data is to be inserted. column1, column2, and column3 are the column names of the table, and their values are those followed by the VALUES keyword. Value definition.
2.2 Use the mysqli_query() function to write data
The mysqli_query() function is a method in the MySQLi extension, using the following syntax:
mysqli_query($con,"INSERT INTO table_name (column1, column2, column3) VALUES ('value1', 'value2', 'value3')");
Where, $con is the previously created The connection object, INSERT INTO, column1, column2, column3, VALUES and other parameters have the same meaning as when using the mysql_query() function.
2.3 Use PDO to write data
There are several ways to write data to the database in PDO, among which exec() is the simplest method:
$stmt = $con->prepare("INSERT INTO table_name (column1,column2,column3) VALUES (:value1,:value2,:value3)"); $stmt->bindParam(':value1', $value1); $stmt->bindParam(':value2', $value2); $stmt->bindParam(':value3', $value3); $value1 = 'value1'; $value2 = 'value2'; $value3 = 'value3'; $stmt->execute();
Among them, stmt is a PDOStatement object, which represents the SQL statement to be executed. This code will bind the parameter value using bindParam(). In this case, pass the value to bindParam() via $key => $value array. Finally, the SQL statement is executed by calling the execute() method.
3. Complete example
The following is a complete PHP example that demonstrates how to connect to a MySQL database and insert data into a table:
This simple example uses mysqli connects to the MySQL database and then uses mysqli_query() to insert data into the table.
In general, by using the above steps of connecting to the database and writing data, combined with various PHP tools and functions, PHP developers can easily implement the function of adding data to the database.
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