background:
In their company Oracle installation, then Oracle listener addresses are written in the company's address
Later, due to the needs of the project office transferred to the customer,
About half a year not to sys user login the database.
In a recent study on the way to work Django, involving intermediate connection to the database, users today want to create a new, dedicated Django exercises.
Results using PL / SQL user login administrator, reported ORA-12541: no listener.
I followed the course of the following steps to resolve the problem:
Step1. Try to log SQL Plus
Result: you can log in successfully. Description password no problem, continue to find the cause of the problem.
Step2. Check whether the listener is starting
Methods: w10 enter service in the lower left corner of the system input box, enter the service program to see if the Oracle Listener has been started
Results: listener is stopped, as shown below:
Right-click on [restart].
Result: The system reported: automatic stop and then start (specifically say what I do not remember, is unable to start, sorry for not leaving before the screenshot)
Step3. Attempt to modify a file monitor
Methods: go to the following path .. \ Oracle \ product \ 11.2.0 \ dbhome_1 \ NETWORK \ ADMIN Find listener.ora file
127.0.0.1 will be added to monitor file.
Results: After saving, re-login, still error.
Step4. Try to configure the monitor
Open the Oracle Net Manager to reconfigure the listener
Result: still being given login
Step5. O & M colleague suggested I enter the database column lowercase orcl when you log in, because my tnsname.ora in SERVICE_NAME = orcl
Results: After the attempt, accident login is successful, ecstatic.
Follow-up:
I had intended this conclusion: orcl case sensitive
The results I log back in using uppercase ORCL, think of a time error cut shots, found uppercase ORCL can also log in successfully.
I do not know what caused the cause of a personal feeling Step4 greatest impact.