System.Data.OracleClient requires Oracle client software version 8.1.7 or greater
Environment: Oracle 10g
Reason 1: The problem of environment variables,
solution:
Right-click on My Computer -> Content -> Advanced -> Environment Variables -> Double-click the Path item in the system variable, enter a semicolon at the end of the variable value, and then copy Oracle's Bin directory to C:\oracle\product\10.2.0\ client_1\BIN (Please find the installation directory of your local Oralce client for this directory) and paste it in, then click three OK all the way to return to the desktop. Re-open a cmd window, enter echo %path%, and find that there is Oracle's BIN directory, so the Path is set. Finally run iisreset to restart IIS, the problem is solved.
PS: In fact, it is found that the original Path also has this path, but it is all lowercase.
Reason 2: There is a problem with the installation package,
After installing an Oracle 10g client on the company's server, this problem will occur, and there is no way to solve it. The same environment (virtual machine copy) can be solved by downloading it from the official website.