Is there accredited international courses in the database administration field?

MCSA SQL Server

OCA , OCP For ORACLE

Yes, I have OCA Certificate

Most certainly. Oracle University has several courses to train newbies and experienced professionals in the area of Database administration.  You can take courses that lead you to specific proficiency levels/certifications like Associate, Professional and Masters and then appear at the qualifying exam to avail the certificate.

Yes all  the technologies have thier reputable Accredited courses and certification. like OCP, ODI, ORACLE APF, MSCE(4 PAPERS).

Yes, all of the technologies have thier own reputable Accredited studies and certification.

in databse there are:

Oracle

Microsoft

Almost all technologies all Os platforms have internationally recognized certifications.

THERE IS MANY COURSES RELATED TO DATABASES.

OCP, ODI, ORACLE APF, MSCE(4 PAPERS).

almost all technologies all Os platforms have internationally recognized certifications. some more highly recognized than others. same applies to database administration depending on which platform you choose i.e. Microsoft technologies or non Microsoft you can find internationally recognized institutions offering various certification here you will find all database related Microsoft certifications   

https://www.microsoft.com/en-us/learning/sql-certification.aspx