Application. Yml

mybatis:
  mapper-locations: classpath:mapper/*.xml  # represents all XML files in the resources/mapper directory
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Create mapper. Java and mapper. XML



Mapper. Java and mapper. XML are created in pairs

// EmployeeMapper.java
/ /... Omit package name and import

public interface EmployeeMapper {
    List<Employee> findAll(a);
}
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<! -- EmployeeMapper.xml -->

      
<! DOCTYPEmapper PUBLIC "- / / mybatis.org//DTD Mapper / 3.0 / EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace = "com.example.dao.EmployeeMapper">
    <resultMap id = "Employee" type = "com.example.pojo.Employee">
        <result property = "id" column = "id"/>
        <result property = "name" column = "name"/>
        <result property = "role" column = "role"/>
    </resultMap>
    <select id = "findAll" resultMap = "Employee">
        SELECT * FROM payroll
    </select>
</mapper>
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Add MapperScan annotations


@SpringBootApplication
@MapperScan("com.example.payroll.dao") // replace the package with * mapper. Java in parentheses
public class PayrollApplication {
	public static void main(String[] args) { SpringApplication.run(PayrollApplication.class, args); }}Copy the code