Fix MyBatis NullPointerException: Query Solutions

The MyBatis query may throw a NullPointerException when the query result is null. There are several ways to resolve this issue.

1. Ensure the SQL query is correct: First, verify that the SQL query is correct by executing the corresponding SQL statement in the database client to see if it returns results.
2. Dealing with empty results: After querying with MyBatis, it is necessary to handle the results to prevent a NullPointerException. This can be done using an if statement or an Optional object.
3. Utilize the appropriate querying method: MyBatis offers various querying methods to choose from depending on your needs, such as the selectOne method which ensures only one result is returned, avoiding null values.
4. Use resultMap to map the result set: By using resultMap in the Mapper configuration file, one can effectively handle any null values that may exist in the result set.
5. Viewing logs: If none of the above methods work, you can check MyBatis log information to identify the specific error reason and further investigate and solve the issue.

The issue of MyBatis query returning null pointer exceptions can be effectively addressed using the methods described above.