mistake
When connecting to Oracle, it prompts "oracle library is not loaded".
reason
The oci.dll version is incorrect or the oci.dll is not configured. Because Navicat connects to the Oracle server through the Oracle client, the Oracle client is divided into two types, one is the standard version and the other is the simple version, namely Oracle Install Client. When we use Navicat, we usually include multiple versions of OCI in our installation path. If an error occurs when using Navicat to connect to the Oracle server, it is mostly because the local OCI version of Navicat does not match the Oracle server. So what we have to do is download the corresponding version of OCI to match the Oracle server we installed.
solve
去Oracle官网下载Oracle Instant Client Downloads：https://www.oracle.com/database/technologies/instant-client/downloads.html
I chose the classic 12 version
Extract it to the English path:
Open the Navicat Premium program, open "Tools-Options-Environment-OCI Environment-OCI library (oci.dll)", and then copy what you just Fill in the complete directory of the oci.dll file in the downloaded folder and click OK.
Then restart Navicat and the connection is OK