It because your php do not support oci8!
if you use Windows:
Download instantclient-basic-windows from here
Ccreate folder
cd E:/wamp64/bin
mkdir oracle
Move downloaded instantclient package into /oracle
mv instantclient-* E:/wamp64/bin/oracle
unzip instantclient-basic-windows.x64-12.1.0.2.0.zip
Add instantclient_xx to your Path and Edit php.ini
Uncomment them
extension=php_oci8_12c.dll
extension=php_odbc.dll
restart your wamp you'll see the oci8
<?
phpinfo().
if you use Linux:
Download instantclient-basic-linux and instantclient-sdk-linux from here, and unzip it in a dir.
mkdir /opt/oracle
mv instantclient-* /opt/oracle
unzip instantclient-basic-linux-x86-64-11.2.0.2.0
unzip instantclient-sdk-linux-x86-64-11.2.0.2.0
mv instantclient_11_2 instantclient
cd /opt
chown -R root:www-data /opt/oracle
echo /opt/oracle/instantclient > /etc/ld.so.conf.d/oracle-instantclient
ldconfig
cd /opt/oracle/instantclient
ln -s libclntsh.so.* libclntsh.so
ln -s libocci.so.* libocci.so
you neet to input 'instantclient,/opt/oracle/instantclient'
pecl install oci8
after finish.check if you have pci8.so in directory like /usr/lib/php/20151012
cd /etc/php/7.0/mods-available/
vi oci.ini // extension=oci8.so
cd /etc/php/7.0/fpm/conf.d/
ln -s /etc/php/7.0/mods-available/oci.ini 20-oci.ini
append path
vi /etc/environment
# append
export LD_LIBRARY_PATH="/opt/oracle/instantclient"
export TNS_ADMIN="/opt/oracle/instantclient"
export ORACLE_BASE="/opt/oracle/instantclient"
export ORACLE_HOME=$ORACLE_BASE
Finally
service php7.0-fpm restart