Oracle TnsPing is correct, pl/SQL ora-12154 cannot resolve the specified connection identifier Solution

Oracle TnsPing is correct, pl/SQL ora-12154 cannot resolve the resolution of the specified connection identifier to tnsnames in C: \ oracle \ ora92 \ network \ ADMIN \ SAMPLE. copy the ora file to C: \ oracle \ ora92 \ network \ ADMIN and try again! Install only one version of client 1. Open. Start -- program -- Oracle-OraHome92 -- Configuration and Migration Tools -- Net Configuration Assistant2, select "naming method Configuration" -- next -- select "local", "Host Name", "Oracle Names "-- step 3. Confirm OK. Open PLSQL with two versions installed on the client, and prompt that the user name and password are entered. Cancel. In this way, go to the PLSQL Developer main interface, choose Tools-Preferences, and select Oracle-Connection in the settings window, in the corresponding settings window, find Oracle Home, select OraHome92, Save settings, www.2cto.com, and restart PLSQL Developer. Then, you can log on to pl/SQL normally, oracle 9i and 10g coexist. Solution: Open PL/SQL development, unenter the user name and password, tool-preference-connection, modify the oracle Home directory name, and restart PL/SQL development, successful. Another method is to modify the Windows environment variable: Add a variable named TNS_MAIN = admin directory path, for example, C: \ oracle \ product \ 10.2.0 \ client_1 \ NETWORK \ ADMIN author jamex