@Param Not Working in MyBatis: Solutions

The @param annotation in MyBatis is used to pass parameters to SQL statements. If the @param annotation is not working, it may be due to mismatched parameter names, causing the parameters to not be passed correctly. One solution is as follows:

1. Check parameter names: make sure that the parameter names in the @param annotation are consistent with the parameter names in the SQL statement. For example, if the parameter name in the SQL statement is #{username}, then the parameter name in the @param annotation should also be username.
2. By using the @Param annotation: you can specify an alias for a parameter if the parameter name does not match, in order to correctly pass the parameter. For example, @Param(“username”) String name.
3. Passing parameters with Map: If you are unable to resolve mismatched parameter names, consider using a Map to pass parameters so you do not have to worry about matching parameter names. For example, #{param.username}.
4. Check SQL statements: ensure that the parameter names in the SQL statements are consistent with the actual parameters used to avoid invalid @param annotations due to mismatched parameter names.

If the issue of @Param annotation not taking effect in MyBatis persists after trying the above methods, it may be caused by other reasons. In that case, you can further inspect the code logic and debug to troubleshoot.