Connect Apache Http server with Oracle
I would try to go with Oracle without ODBC. ODBC adds one more layer and both Oracle and ODBC usually are not as well tested as MySQL or PostgreSQL. Like others noticed the problem is with checking for OCIEnvCreate in -lclntsh... no. The most probably configure cannot find required libraries. You should try two things:
 1. Check config.log for error messages about OCIEnvCreate.
 2. Shouldn't httpd's configure command line say LDFLAGS=-L$ORACLE_HOME/lib? Of course I install instant client from RPMs but libclntsh.so is in lib/ subdirectory.