(PECL PDO_PGSQL >= 0.1.0)
PDO_PGSQL DSN — Connecting to PostgreSQL databases
The PDO_PGSQL Data Source Name (DSN) is composed of the following elements, delimited by spaces or semicolons:
The DSN prefix is pgsql:.
The hostname on which the database server resides.
The port on which the database server is running.
The name of the database.
The name of the user for the connection. If you specify the user name in the DSN, PDO ignores the value of the user name argument in the PDO constructor.
The password of the user for the connection. If you specify the password in the DSN, PDO ignores the value of the password argument in the PDO constructor.
Note:
The bytea fields are returned as streams.
Example #1 PDO_PGSQL DSN examples
The following example shows a PDO_PGSQL DSN for connecting to a PostgreSQL database:
pgsql:host=localhost;port=5432;dbname=testdb;user=bruce;password=mypass
How to add application name to dsn string.
You can make query like "SET application_name=...." or just add something to dsn string:
$dbh = new PDO('....;options=--application_name=WEB_APPLICATION');
We have a lot of php apps and it's hard to understand what app made slow query. But this small hack help us.
We can also alternatively put the username and password in the second and third argument of PDO::__construct()
<?php
$dbh = new PDO("pgsql:dbname=$dbname;host=$host", $dbuser, $dbpass);
?>
I must say Chris C. is correct, yet sadly downvoted. It is irrelevant if semicolons are converted to spaces in the DSN string. The entire point of PDO is expressed in the first word of the acronym: "Portable"; it provides a uniform way of accessing databases of various flavors, and since a semicolon is its standard DSN delimiter, it SHOULD be used (at miniscule overhead if taking conversion into account, mind you) to facilitate uniformity and potentially ease portability.
I wanted to point out something that is not obvious from the documentation here or in any google searches that I've done. Everything after the 'pgsql:' is passed to the PQconnectdb function of the pgsql library as a connection string. This means 2 important key things:
1) 'username' is not a valid option of the PQconnectdb connection string. Use 'user' instead (ie 'user=<username>' instead of 'username=<username>').
2) You can utilize ANY option of the PQconnectdb function in this way. For those trying to figure out how to enable ssl connections through the pgsql PDO connection process, like me, as per Postgresql standards, the 'sslmode' parameter can be set via the DSN. So, for example, 'sslmode=require' will require an ssl connection. Look at the documentation for the pgsql library version you are using for all options of both the sslmode parameter and any other parameters that are available.
The DSN syntax shown here did not work for me, but this did:
<?php
$dbh = new PDO("pgsql:dbname=$dbname;host=$host", $username, $password );
?>
As opposed to
<?php
$dbh = new PDO('pgsql:dbname=$dbname;
host=$host;
username=$username;
password=$password');
?>
Which makes sense and is more PGSQL standard.
You can also connect to PostgreSQL via a UNIX domain socket by leaving the host empty. This should have less overhead than using TCP e.g.:
$dbh = new PDO('pgsql:user=exampleuser dbname=exampledb password=examplepass');
In fact as the C library call PQconnectdb underlies this implementation, you can supply anything that this library call would take - the "pgsql:" prefix gets stripped off before PQconnectdb is called, and if you supply any of the optional arguments (e.g. user), then these arguments will be added to the string that you supplied... Check the docs for your relevant PostgreSQL client library: e.g.
http://www.postgresql.org/docs/8.3/static/libpq-connect.html
If you really want, you can use ';'s to separate your arguments - these will just be converted to spaces before PQconnectdb is called.
Tim.
The PDO_PGSQL DSN should be seperated by semi-colons not spaces. It should follow the convention like the rest of the PDO DSNs.
'pgsql:dbname=example;user=nobody;password=change_me;host=localhost'