You can enable the SQL Server in 4D Server to allow external connections (ODBC/SQL/PDO) connections to the 4D Server.
Once you have the SQL Server enabled then you can either use the 4D ODBC Driver on Windows/Mac or PDO_4D with PHP on Windows/Mac/Linux.
This tech tip demonstrates how to connect to 4D using PHP with both of these methods:
PDO_4D:
<?php$dsn = '4D:host=localhost;port=19812;charset=UTF-8';$user = 'Administrator';$pswd = 'test';$db = new PDO($dsn, $user, $pswd);$db->exec('CREATE TABLE IF NOT EXISTS myTable(id INT NOT NULL, value VARCHAR(100))');unset($db);echo 'done'; // if you see this then the code ran successfully?> ODBC:
<?php$dsn = 'dsnName'; //DSN created by the 4D ODBC driver$user = 'username';$pswd = 'password';$name ='Joe';$conn = odbc_connect($dsn,$user,$pswd);$sql_text = "INSERT INTO Customers(Name) VALUES('".$name."')";$sql = odbc_prepare($conn,$sql_text);$res = odbc_execute($sql);echo $res; // if you see this then the code ran successfully?>More connectivity options for 4D are listed on github here and here
