Error establishing a database connection

Dear Sir,

I have points all the domains to main domain IP
and add * . and if I type other domains, it should forward to main website, but now after I test other domains,have
"Error establishing a database connection"
main domain is OK.

The error may be caused after I change Cpanel?
I follow this like

2. If you have access to WHM – log into WHM and go to Edit DNS Zone. Select the domain you want to enable wildcard subdomains from the list.

Under Add New Entries Below this Line fill in the fields so that they look like this:

* 14400 IN A
I fill in * 14400 IN A my main ip
Edit DNS Zone screen
; cPanel first: (update_time):1374761301 Cpanel::ZoneFile::VERSION:1.3 latest:
; Zone file for
$TTL 14400
My question is "Error establishing a database connection" is cansed by that.

What I should edit or reset,