pgsql: double quotes not allowed inside query string

I remember from a different D6 case that doubles quotes are not allowed:

Wrong:

$count_sql = 'SELECT COUNT(DISTINCT t.sid) translation_count, r.pid, t.is_suggestion FROM {l10n_community_release} r INNER JOIN {l10n_community_file} f ON r.rid = f.rid INNER JOIN {l10n_community_line} l ON f.fid = l.fid INNER JOIN {l10n_community_string} s ON l.sid = s.sid LEFT JOIN {l10n_community_translation} t ON s.sid = t.sid WHERE t.is_active = 1 AND t.translation != "" ';

Good:

$count_sql = "SELECT COUNT(DISTINCT t.sid) translation_count, r.pid, t.is_suggestion FROM {l10n_community_release} r INNER JOIN {l10n_community_file} f ON r.rid = f.rid INNER JOIN {l10n_community_line} l ON f.fid = l.fid INNER JOIN {l10n_community_string} s ON l.sid = s.sid LEFT JOIN {l10n_community_translation} t ON s.sid = t.sid WHERE t.is_active = 1 AND t.translation != ''";

There could be much more bugs like this... i only saw this while it was 3 lines away from a different bug and therefor on my screen.