Solution to PLSQL connection oracle error ora-12154 tns could not parse the specified connection identifier

PLSQL connection oracle error ora-12154 tns cannot resolve the specified connection identifier solution when doing the project oracle is used but with plsql prompt ora-12154 tns cannot parse the specified connection identifier, however, running sqlplus and Navicat for MySQL can both be used. After the problem is found by Du Niang, most of them mean that the oracle configuration is wrong, but there is still no way to use it after modification, later I thought about whether it was a plsql issue. After I uninstalled it and reinstalled it, I found an error. This is dueto Oracle Bug 3807408 has not been solved by Baidu, however, some cannot be used with parentheses. Later I thought it would be possible to use the plsql installation path. because the default installation path for 64-bit Windows 7 is C: \ Program Files (x86) and 32-bit is C: \ Program Files, many users cannot use 64-bit Files, generally, 32-bit data can be used. many people in our class are unable to use a 32-bit system because they can use a 64-bit system. Because of this problem, the system will be reinstalled and this issue will be specially issued for your reference.