What are the steps for configuring one-to-many mapping …
The steps for configuring a one-to-many mapping in MyBatis are as follows:
- Create two entity classes, each representing one side of the one-to-many relationship.
- Create a Mapper interface and define the query method.
- Configure the mapping relationship of query results in the Mapper interface using the @Result annotation or in the corresponding XML file using tags.
- In the corresponding XML file, configure a one-to-many relationship using tags to represent the “many” side and tags to represent the “one” side.
- In the corresponding XML file, write a query statement using JOIN to link the one-to-many relationships, and use GROUP BY to group the results.
- Define the parameters and return type for the query method in the corresponding Mapper interface.
- Configure the scanning path for Mapper interfaces and related configurations for MyBatis in the project’s configuration file.
- In the code, obtain an instance of the Mapper interface by using the getMapper method of SqlSession, and then call the query method to perform a query.
- Retrieve the query results, encapsulate them into entity classes using the associated mapping relationships, and obtain a one-to-many result.
The above are the main steps for configuring one-to-many mapping in MyBatis. Adjustments can be made according to actual needs, such as configuring and coding appropriately for inserting or updating one-to-many operations.