As it turns out, environment variables affect the environment that processes can run in. In essence, they become a part of the environment in which a process is running and as such, the process has access to those variables. Adding a utility in the PATH variable allows you to access it from anywhere using the command line interface and usually when you install tools that come with a command line utility, they are added to the PATH variable automatically.  This, in return, allows you to run the tools directly without having to add them manually. However, in some cases, when this does not work out, you will have to do so manually and everything should be good. In addition to that, sometimes the path provided is not correct which can also result in the error message mentioned above.  There are two ways using which you can go about this. The first is through a command line interface and the second takes you through a graphical user interface. We will be mentioning both of them so you can follow any that you like. With that said, let us get started without any further ado. 

1. Add SQLPLUS to PATH Variable using Command Prompt

The first way that we are going to go through to resolve the error message in question is using the command prompt. If you are comfortable with using the command prompt, then this should be pretty easy for you. However, if you would like to avoid a command line driven solution, you can skip this and move on to the next method down below which takes you through a graphical interface approach.  Using the command prompt, you can easily set the PATH variable to include the bin directory of Oracle so that sqlplus can be executed from anywhere. To do this, follow the instructions down below:

2. Add SQLPLUS to Path Variable using GUI

If you are not comfortable with adding the bin folder of your Oracle installation to the PATH variable using the command prompt, you can also choose to edit the environment variables via the graphical interface. This is pretty simple and easy to do as well. To do this, just follow the instructions given down below:

Fix: Python is not recognized as an internal or external commandFix: ‘git’ is not recognized as an internal or external commandFix: ‘pip’ is not recognized as an internal or external commandFix: ‘conda’ is not recognized as an internal or external command, operable… Fix  SQLPLUS is Not Recognized as Internal Command - 46Fix  SQLPLUS is Not Recognized as Internal Command - 56Fix  SQLPLUS is Not Recognized as Internal Command - 12Fix  SQLPLUS is Not Recognized as Internal Command - 25Fix  SQLPLUS is Not Recognized as Internal Command - 18Fix  SQLPLUS is Not Recognized as Internal Command - 1Fix  SQLPLUS is Not Recognized as Internal Command - 47Fix  SQLPLUS is Not Recognized as Internal Command - 7