mybatis详解-(16)分步查询及延迟加载

前面文章介绍了都是一个sql语句完成所有的查询操作，包括在执行联合查询的时候也是一个sql语句完成查询，然后将查询结果通过resultMap进行封装。mybatis也提供了分步查询的功能，在完成一个操作之后，将查询的结果使用到第二个三个查询参数中完成所有的查询。具体如何实现，还是结合示例做展示：

分步查询

1）association
使用association实现分步查询操作。

创建实体

Employee和Department

package org.mybatis.resultmap;

public class Employee {
   
     
    private Integer id;
    private String lastName;
    private String email;
    private String gender;
    private Department department;

    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getGender() {
        return gender;
    }
    public void setGender(String gender) {
        this.gender = gender;
    }
    public Department getDepartment() {
        return department;
    }
    public void setDepartment(Department department) {
        this.department = department;
    }
    @Override
    public String toString() {
        return "Employee [id=" + id + ", lastName=" + lastName + ", email="
                + email + ", gender=" + gender + ", department=" + department
                + "]";
    }

}