postgresql equivalent of mysql errno

You're correct. You can use pg_last_error() to get the last error for the connection.

Example:

pg_connect(...) or die('Could not connect: ' . pg_last_error());

I disagree with Francois Deschene's answer.

Unfortunately, the pg API seems a bit weaker than the MySQLi API. I've considered using PDO, but I haven't looked too into that yet.

To answer your question, you'll have to go somewhat out of the way to get the equivalent to "mysqli_errno" (that is, the actual error number). pg_last_error() returns a string, not a number. And numbers are a bit easier to deal with.

http://www.postgresql.org/docs/8.1/static/errcodes-appendix.html

Anyway, to get the error NUMBER, you'll have to use a combination of functions.

pg_send_query_params(blah blah); // or pg_send_query() if you don't use prepared statements
$result = pg_get_result($connection);
$result_status = pg_result_status($result);
$mysqli_errno_equivalent = pg_result_error_field($result_status, PGSQL_DIAG_SQLSTATE);

Hopefully, someone else will come up with a easier solution. But this is what I've been using in my code (because the error numbers in PostgreSQL Appendix A are much easier to deal with than the full text error strings).

Fortunately, it is trivial to write a simple wrapper around this so you don't repeat yourself over and over again.

The documentation seems to imply that this is the best way to get the number. http://www.php.net/manual/en/function.pg-result-error-field.php