使用PDO运行Postgres查询：为foreach（）提供的参数无效

Question

Trying to follow the example in http://php.net/manual/en/pdo.query.php and connecting with

$dbh = new PDO('pgsql:host=localhost;port=5432;dbname=example;user=postgres');

and running query

foreach ($dbh->query('SELECT * from Animals') as $row) {
  print $row;
}

I am getting the error:

Warning: Invalid argument supplied for foreach() in /Users/zaitsev/tests/pg-php/pdo-test.php on line 13

What is wrong here?

Answer 1

As manual says:

PDO::query() returns a PDOStatement object, or FALSE on failure.

It's very probable that your query is returning false by some failure. Ensure your PostgreSQL connection and try out execute your query directly on PostgreSQL (PGAdmin).