When we use PLSQL to connect to the Oracle database, enter the database name, user name and password, the connection is successful.

When we use Navicat Premium to connect to the database, we are not able to connect to Oracle for some reason.The ORA12514 listener is currently unable to recognize the service requested in the connection descriptor

According to my experience, there may be many reasons for reporting this error, which I have recently resolved through the following actions.

1. Make sure your Oracle service is started. Enter Win +R on the keyboard, and then enter services. MSC in the box in the lower left corner.

2. Check whether the IP address, service name, user name and password are correct when connecting to the database. The default service name is ORCL, but the configuration file may have been changed when we import the project, so we need to check the Oracle database configuration file.

Ora: E:\oracle\product\11.2.0\dbhome_1\NETWORK\ADMIN

4. Open the tnsnames.ora file and view information as shown in the following figure.

5. You want to connect to the Oracle database IP address, port number, service name and your user name, password into the connection properties, click the connection test, the connection is successful. Note that the default port number is 1521 and the default service name is ORCL. If you have changed the service name, make sure to change the service name accordingly.

Summary: I just joined a new company, navicat has been reporting ORA-12514 for connecting to the database. After many times of searching online information, I finally found that the reason is that the service name has not been modified. Here I summarize my experience, hoping to help you!