There are similar topics in here but the solutions did not fix my problem.
My OS is Windows 7-64 bit
I use Wampserver 2.5-64 bit
I downloaded instantclient_12_1 64 bit and put it into the D:/ directory
I added the PATH which shows the directory of the instant client.(To the system)
I delete ";" characters in php.ini file(I am using 11g oracle environment)
;extension=php_oci8.dll ; Use with Oracle 10gR2 Instant Client
extension=php_oci8_11g.dll ; Use with Oracle 11gR2 Instant Client
I can see OCI definitions when I look at the phpinfo() in localhost
I restarted the pc after I made changes
I restarted the wampserver after I made changes
I tried many ways and advices to come up with the problem but they did not fix the problem