Good day,
it think you are using mysql, right? if you use DSN please verify check other drivers there are well known bug in some versions - as result drivers very unstable.
have checked files system? have you tried on other sql server or direct query via console?
as i see you selected PHP, so i am sure u are using DSN if sql server is used.
I have 7+ years of experience as Windows Administrator at various organizations.
Many of them have complex Windows-Linux environment. Core was built with Microsoft products, such as: Windows Server 2003-2012R2 (Active Directory, DNS, DHCP, NPS, RRAS etc), SQL Server 2000-2012, mysql, also i am professional we developer (PHP).