What is the purpose of mybatis resultmap?

The purpose of MyBatis ResultMap is to map query results to Java objects or collections. By defining a ResultMap, you can specify the mapping relationship between each column in the query result and the properties of the Java object.

Specifically, ResultMap can achieve the following functions:

1. Define the mapping relationship between query results and Java objects: You can specify the correspondence between columns in query results and attributes of Java objects, including column names, attribute names, data types, etc.
2. Manage complex query results: When the query result involves multiple tables or nested queries, ResultMap can be used to handle complex mapping relationships.
3. To handle the association relationships of the result set, ResultMap can be used when there are associations in the query results, including one-to-one, one-to-many, many-to-one, many-to-many relationships.
4. Provide type conversion of attributes: Attribute value type conversion can be performed through ResultMap, converting the data in the query result into the property type of a Java object.

In summary, the purpose of MyBatis ResultMap is to define the mapping relationship between query results and Java objects, enabling query results to be easily mapped to Java objects, simplifying the development process.