In case of PostgreSQL it is documented here.
With JDBC, a database is represented by a URL (Uniform Resource Locator). With PostgreSQL™, this takes one of the following forms:
In case of MySQL it is documented here.
The general format for a JDBC URL for connecting to a MySQL server is as follows, with items in square brackets (
[ ]) being optional:
jdbc:mysql://[host1][:port1][,[host2][:port2]]...[/[database]] » [?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]
In case of Oracle it is documented here.
There are 2 URL syntax, old syntax which will only work with SID and the new one with Oracle service name.