http://www.oracle.com/technetwork/database/database-technologies/instant-client/downloads/index.html
Download the client that matches the computer version here, unzip it to any directory,
Set environment variables in the computer advanced system settings:
ORACLE_HOME=The directory location where the downloaded file is decompressed,
At the same time, add $ORACLE_HOME to the path, download the file from the oracle server, tnsnames.ora,
Put it in the $ORACLE_HOME directory, then add TNS_ADMIN=tnsnames.ora to the directory where the advanced system settings are located
Download and install the plsql client from the Internet, the registration code can be searched online, and then open plsql, you may be able to directly see the associated database information, if not, enter the plsql interface without logging in, tool-preferences, and manually set oracle_home and oracle_lib