How to utilize automatic mapping feature in MyBatis?

When using automatic mapping in MyBatis, you should configure the resultMap element in the mapping file and set the autoMapping attribute to true. For example:

<resultMap id="userResultMap" type="User" autoMapping="true">
    <id property="id" column="id"/>
    <result property="username" column="username"/>
    <result property="password" column="password"/>
</resultMap>

In the example above, we created a resultMap element and set the autoMapping attribute to true, so that MyBatis will automatically map the columns in the query result set to the properties of the entity class.

Furthermore, it is important to note the following points when using the automatic mapping feature:

1. The column names in the query result set must match the attribute names of the entity class, otherwise the automatic mapping function may not work correctly.
2. You can specify the properties to be automatically mapped in the resultMap element, or you can use the wildcard * to automatically map all properties.
3. If the column names in the query result set do not match the property names, you can use aliases to resolve the mapping issue, for example, using the AS keyword to specify an alias for a column in the query statement.

Overall, using the auto mapping feature can simplify the configuration work of MyBatis, allowing developers to focus more on implementing business logic.