oracle database error

Oracle database error

Oracle database is one of the most commonly used databases in the industry. However, in the process of using Oracle database, various problems will inevitably occur, such as database connection failure, syntax Errors, deadlocks, etc. Among them, database errors are the most common problems we encounter when using Oracle database. Let's summarize the common errors and solutions of Oracle database.

1. ORA-01017: invalid username/password; logon denied

This is a very common error. The reason is that the username or password is entered incorrectly, or there is no This is caused by user permissions.

Solution:

1. Confirm that the username and password are correct, and check whether there are any capitalization issues.
2. Check the user's permissions to see if they have permission to access the database.
3. ORA-12154: TNS:could not resolve the connect identifier specified

This is a network connection error. It usually occurs when the client connects to the database because the service cannot be resolved. Caused by identifiers such as names or SIDs.

Solution:

1. Confirm whether the client parameter file (tnsnames.ora) is configured correctly, and check whether the naming identifier is correct.
2. Confirm whether the network is normal and whether the database instance has been started.
3. Check the firewall settings and confirm whether the port is open.
4. ORA-00933: SQL command not properly ended

This error is caused by the syntax problem of the SQL statement, usually because the SQL statement is not ended correctly.

Solution:

1. Check whether the SQL statement ends correctly, such as missing semicolons or other keywords.
2. Check whether the SQL statement is correct and complies with Oracle database specifications.
3. ORA-00060: deadlock detected while waiting for resource

Deadlock is a common problem. Two or more processes block each other while waiting for resources and cannot continue to execute.

Solution:

1. Use Oracle's lock monitoring tool to detect deadlock processes and corresponding SQL statements.
2. Alleviate the deadlock problem by appropriately increasing the resources of the locked computer, such as increasing memory, etc.
3. ORA-01722: invalid number

This error is caused by performing mathematical or comparison operations on non-numeric type data (the data is in a non-numeric type field). For example, comparing character data to numeric data will produce this error.

Solution:

1. Confirm whether the data type is correct.
2. Confirm whether the statement is correct, such as using the correct operator, appropriate parameters and format.
3. ORA-00942: table or view does not exist

This error is caused by the query or operation table or view not existing or spelling error.

Solution:

1. Confirm whether the queried table or view exists and check whether the spelling is correct.
2. Confirm whether the user has permission to access the table or view.

Summary

Oracle database is a powerful database, but various problems will inevitably occur during use, including the above-mentioned 6 common errors. In order to solve these problems, you need to have an in-depth understanding of Oracle database and be good at using Oracle tools and technologies, such as monitoring tools, debugging technology, etc. Only through continuous learning and practice can database errors be minimized in the process of using Oracle database.

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