How to solve the issue when specifying jdbctype in MyBatis is not effective?

If the specified JdbcType in MyBatis is not effective, you can try the following method to resolve it:

1. Check the database field definitions to ensure that the field types in the database table match the JdbcType specified in MyBatis. If the database field types do not match the specified JdbcType, it may cause the JdbcType to not take effect.
2. Check the MyBatis configuration file to ensure that the correct database connection information and type aliases are specified. Incorrect database connection information in the configuration file may cause JdbcType to not take effect.
3. Check the Mapper interface and mapping files to ensure that the parameters and result mappings are correct. Incorrect mappings could lead to ineffective JdbcType.
4. Check the version of MyBatis: make sure you are using the latest version of MyBatis, as some earlier versions may have issues where JdbcType is not effective. Upgrading to the latest version may resolve this issue.

If the above methods do not solve the problem, you can try recompiling and deploying the project, or consult the official documentation and community of MyBatis for more solutions.