PL/SQL itself cannot access the 64-bit Oracle client on 64 systems, but there are two solutions. One is to install a 32-bit ORACLE client, however, I felt too big. I found the second method on the Internet and it was feasible after experiment.
Environment: WIN7 64-bit
ORACLE 11g 64-bit
PL/SQL DEVELOPMENT 7.1.4
You need to download the Instant Client from the ORACLE website
Click here.
You must download a 32-bit system. I cannot download a 64-bit system. After downloading the system, decompress it and put it in a folder named instantclient_10_2, copy all the network folders under your ORACLE installation directory to the instantclient_10_2 folder, and then start PL/SQL, in PLSQL Developer, choose Tools> Preferences> options> "Oracle Home" and "OCI Library ",
For example:
Instantclient_10_2 packed in D: \ instantclient_10_2
Then: Oracle Home is D: \ instantclient_10_2
The OCI Library is D: \ instantclient_10_2 \ oci. dll. Restart PL/SQL to log on normally.