mybatis resultMap ofType

MyBatis是一个Java持久化框架，提供了一种将数据库查询结果映射到Java对象的方式。在MyBatis中，resultMap是用于定义查询结果映射规则的配置元素之一。

resultMap元素用于指定如何将查询结果映射到Java对象的属性上。其中，ofType属性是resultMap元素的一个子元素，用于指定映射的Java对象类型。

使用ofType属性，可以指定一个Java类作为映射的目标类型。这样，在查询结果映射过程中，MyBatis会将查询结果自动转换为指定类型的Java对象。

以下是ofType属性的使用示例：

<resultMap id="userResultMap" type="com.example.User">
  <id property="id" column="user_id"/>
  <result property="username" column="user_name"/>
  <result property="email" column="user_email"/>
</resultMap>

在上述示例中，ofType属性指定了映射的目标类型为com.example.User类。这样，当执行查询操作时，MyBatis会将查询结果自动转换为User对象。

相关问题

mybatis resultmap

MyBatis ResultMap is a mapping configuration that specifies how the result of a query will be mapped to Java objects. It is used to convert the result set of a SQL query into a Java object.

A ResultMap typically contains one or more ResultMappings, which define the mapping between the columns in the result set and the properties of the Java object. Each ResultMapping specifies the column name, the Java property name, and the Java type of the property.

ResultMaps can be defined in XML or Java annotations. In XML, a ResultMap is defined using the <resultMap> element, while in Java annotations, it is defined using the @ResultMap annotation.

ResultMaps can be reused across different queries, and they can also be nested to handle more complex mappings. MyBatis provides several built-in ResultMap types, including AutoMapping, which automatically maps columns with matching property names, and ConstructorMapping, which maps the result set to a constructor of the Java object.

Overall, ResultMap is an important and flexible feature of MyBatis that allows developers to easily map SQL query results to Java objects.

mybatis resultMap include

MyBatis provides a feature called "resultMap" to map the query results to objects. It allows you to define how the columns in the result set should be mapped to the properties of your Java objects.

To include the result mappings from another resultMap, you can use the "include" element within the resultMap definition. Here's an example:

<resultMap id="BaseResultMap" type="com.example.User">
  <id property="id" column="id"/>
  <result property="name" column="name"/>
  <result property="age" column="age"/>
</resultMap>

<resultMap id="ExtendedResultMap" type="com.example.ExtendedUser" extends="BaseResultMap">
  <result property="extraProperty" column="extra_column"/>
</resultMap>

In the above example, the "ExtendedResultMap" includes the mappings from the "BaseResultMap" using the "extends" attribute. It then adds an additional result mapping for the "extraProperty" field.

This allows you to reuse and extend existing result maps, making your code more maintainable and reducing duplication.