mapper namespace

Mapper namespace refers to the namespace in which a mapper class is defined. In the context of object-relational mapping (ORM) frameworks like MyBatis, the mapper namespace is used to identify and locate a specific mapper interface or XML file that contains SQL statements or mappings for database operations.

In MyBatis, a mapper namespace is typically declared in the mapper XML file using the `namespace` attribute. This namespace serves as a unique identifier for the mapper and is used to associate it with the corresponding Java interface or class.

For example, in a MyBatis mapper XML file, you might have:

<mapper namespace="com.example.dao.UserMapper">
    <!-- SQL statements and mappings -->
</mapper>

Here, the `namespace` attribute specifies that the mapper belongs to the `com.example.dao` package and is named `UserMapper`. This allows you to reference and use this mapper in your MyBatis configuration or Java code by using the fully qualified name `com.example.dao.UserMapper`.