The process of php program writing to database

First, we need to connect to the database. In PHP, there are two common ways to connect databases: mysqli and PDO. Among them, mysqli is an improved extension of MySQL, while PDO is a general database abstraction layer that supports multiple databases, such as MySQL, Oracle, SQL Server, etc.

After connecting to the database, we need to define an SQL statement to complete data writing. SQL is a structured query language, which is widely used in database management systems. In PHP, we can write, query, update and delete data through SQL statements.

The following is a sample SQL statement for writing a record to the database:

``` sql

INSERT INTO table name (field 1, field 2, field 3) VALUES (value 1, value 2, value 3)

```

Where, INSERT INTO is the keyword for inserting data, the table name is the table name to insert data, and the data field to insert and the corresponding data value are in parentheses.

Next, call SQL statements in PHP to write data to the database. First, run PDO through PHP to establish a database connection:

``` php

//Configuration database information

$servername = "localhost";

$username = "username";

$password = "password";

$dbname = "myDB";

//Create Connection

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);

//Start writing data

$sql="INSERT INTO myTable (name, age, address) VALUES ('Zhang San ',' 22 ',' Beijing ')";

$conn->exec($sql);

```

In the above code, $servername represents the address of the database server, $username represents the user name when logging in to the database, $password represents the password when logging in to the database, and $dbname represents the name of the database to be connected.

After establishing the database connection, we defined an SQL statement to write the values of the name, age, and address fields into the myTable table.

Finally, execute the SQL statement and write the data by calling the exec function. When the exec function succeeds, it returns true, otherwise it returns false.

The above is the basic process for PHP to write data to the database. It should be noted that in order to ensure the security and correctness of data when it is written to the database, we need to filter and verify the data to prevent SQL injection and other security problems. At the same time, we also need to maintain the stability and performance of the database to ensure the running efficiency and stability of the program.