Example of PHP with Postgresql:
Making the Connection
There are two direct ways to make a connection to PostgreSQL using PHP. They are pg_connect() and pg_pconnect(). The syntax of the two connections is very similar. However, functionally, they are a bit different. The pg_connect() function will create a new connection for each instance of the function. On the other hand, pg_pconnect() will reuse an existing connection to PostgreSQL if one is available.
The following is a simple example of opening a database connection to PostgreSQL:
$connection =
?>
To do the same with pg_pconnect, the syntax is nearly identical:
$connection =
?>
The previous examples open a connection to the database "mydb" on the local host, as the "myuser" user. If the user= parameter is omitted, the user that will be authenticated is the system user that your Web server is running as (for example, "nobody").
The next step would be to actually send a command or query to the PostgreSQL database. This is done in conjunction with the pg_connect() function by using the pg_exec() function.
$connection =
$myresult = pg_exec($connection,
?>
The previous example will connect and execute a query, but not much else. You only have to pass the $connection variable if you have more than one connection to choose from (for example, if you have opened two connections with the pg_connect() function). Therefore, the following code would function identically, if you intend on having only one connection:
$myresult =
?>
If you wanted to make this code a bit more robust, you could add some exception handling:
$connection =
if (!$connection) {
exit;
}
$myresult = pg_exec($connection,
?>
Now we have a connection to PostgreSQL that will alert you if the connection fails. Also, we are executing a simple query. We are not, however, processing the results of the query we sent. Thus, we will want to add some logic on the result set as shown in the following bit of code:
// make our connection
$connection =
// let me know if the connection fails
if (!$connection) {
exit;
}
// declare my query and execute
$myresult = pg_exec($connection,
// process results
for ($lt = 0; $lt < pg_numrows($myresult); $lt++) {
$id = pg_result($myresult, $lt, 0);
$username = pg_result($myresult, $lt, 1);
$fname = pg_result($myresult, $lt, 2);
$lname = pg_result($myresult, $lt, 3);
// print results
\n");
\n");
\n");
\n");
}
?>
