07 mybatisのマルチテーブル操作

mybatisのマルチテーブル操作

データ操作フロー

1、データベース作成

2、javaエンティティオブジェクト作成

3、mapperファイル構成

4、テスト:データ取得

一、一対一

StudioオブジェクトにAddressオブジェクトを含む

studentオブジェクトassociation参照address

1.1、データベーステーブルの作成

create table mybatis_one2one_addresses(
one2one_addr_id int(3) auto_increment not null primary key,
one2one_street varchar(20) not null,
one2one_city varchar(20) not null,
one2one_state varchar(20) not null,
one2one_zip varchar(10),
one2one_country varchar(20));

create table mybatis_one2one_students(
one2one_stud_id int(3)auto_increment not null primary key,
one2one_name varchar(20) not null,
one2one_email varchar(20),
one2one_dob date,
one2one_phone varchar(15),
one2one_addr_id int references addresses(one2one_addr_id));

insert into mybatis_one2one_addresses(one2one_addr_id,one2one_street,one2one_city,one2one_state,one2one_zip,one2one_country) values(1,'redSt','kunshan','W','12345','china');
insert into mybatis_one2one_addresses(one2one_addr_id,one2one_street,one2one_city,one2one_state,one2one_zip,one2one_country) values(2,'blueST','kunshan','W','12345','china');

insert into mybatis_one2one_students(one2one_stud_id,one2one_name,one2one_email,one2one_phone,one2one_addr_id) values(1,'John','[email protected]','123-456-7890',1);
insert into mybatis_one2one_students(one2one_stud_id,one2one_name,one2one_email,one2one_phone,one2one_addr_id) values(2,'Paul','[email protected]','111-222-3333',2);

注:studentオブジェクトにaddressが含まれているため、テーブルが作成され、データ挿入はAddressテーブル

を先に処理する必要があります.
1.2、javaエンティティオブジェクトの作成

get,setメソッド省略

public class One2OneAddress {
    private int addrId;
    private String addrStreet;
    private String addrCity;
    private String addrState;
    private String addrZip;
    private String addrCountry;
}

public class One2OneStudent {
    private int stuId;
    private String stuName;
    private String stuEmail;
    private String stuDob;
    private String stuPhone;
    private One2OneAddress stuAddress = new One2OneAddress();
}

注意:studentクラスでAddressプロパティが直接newするのは、toStringでのポインタ異常を防止するためです

1.3、mapperマッピングファイルの作成:resource/mapper

<mapper namespace="one2oneMapper">
    <resultMap id="one2oneAddress" type="com.demo.mybatis.one2one.One2OneAddress">
        <id property="addrId" column="one2one_addr_id"/>
        <result property="addrStreet" column="one2one_street"/>
        <result property="addrCity" column="one2one_city"/>
        <result property="addrState" column="one2one_state"/>
        <result property="addrZip" column="one2one_zip"/>
        <result property="addrCountry" column="one2one_country"/>
    resultMap>

    <resultMap id="one2oneStudent" type="com.demo.mybatis.one2one.One2OneStudent">
        <id property="stuId" column="one2one_stud_id"/>
        <result property="stuName" column="one2one_name"/>
        <result property="stuEmail" column="one2one_email"/>
        <result property="stuDob" column="one2one_dob"/>
        <result property="stuPhone" column="one2one_phone"/>
        <association property="stuAddress" resultMap="one2oneAddress"/>
    resultMap>

    <select id="selectStudent" parameterType="int" resultMap="one2oneStudent">
        select * from mybatis_one2one_students left outer join mybatis_one2one_addresses
        on mybatis_one2one_students.one2one_addr_id = mybatis_one2one_addresses.one2one_addr_id
        where one2one_stud_id = #{stuId}
    select>

    <select id="selectStudentShot" parameterType="int" resultMap="one2oneStudent">
        select * from mybatis_one2one_students student left outer join mybatis_one2one_addresses address
        on student.one2one_addr_id = address.one2one_addr_id
        where one2one_stud_id = #{stuId}
    select>

mapper>

1.3.1、構成説明:association property=“stuAddress”resultMap=“resultMap=”one 2 oneAddress”

association:has-one

を表す

property="stuAddress":javaエンティティオブジェクトの属性名

resultMap="one 2 oneAddress":参照idがone 2 oneAddressであることを示すマッピング構成

1.3.2、構成id説明:selectStudio

mybatis_one2one_students student:mybatis_one2one_studentsデータベーステーブル略称student

student.one2one_addr_id = address.one2one_addr_id:studentテーブルのaddrIdからAddressテーブルの対応するid値

を取得する
1.4、テスト:データベースからデータを取得する

    @Test
    public void selectStudent() {
        SqlSession session = SessionUtis.getSession();
        One2OneStudent student = session.selectOne("one2oneMapper.selectStudent", 1);
        System.out.println(student.toString());
    }

    @Test
    public void selectStudentShot() {
        SqlSession session = SessionUtis.getSession();
        One2OneStudent student = session.selectOne("one2oneMapper.selectStudentShot", 1);
        System.out.println(student.toString());
    }

二、一対多

1つのclassesオブジェクトに複数のpersonオブジェクトを含む

classesマッピングファイルcollectionでpersonオブジェクトを参照

2.1、データベーステーブルの作成

create table mybatis_one2many_person(
one2many_person_id int(3) auto_increment not null primary key,
one2many_name varchar(100),
one2many_email varchar(100),
one2many_phone varchar(15));

create table mybatis_one2many_classes(
one2many_classes_id int(3) auto_increment not null primary key,
one2many_name varchar(100) not null,
one2many_description varchar(512),
one2many_start_date date ,
one2many_end_date date ,
one2many_person_ids int references mybatis_one2many_tutors (one2many_person_id));


insert into mybatis_one2many_person
(one2many_name,one2many_email,one2many_phone)
values('test name','[email protected]','123-456-7890');

insert into mybatis_one2many_person
(one2many_name,one2many_email,one2many_phone)
values('test name','[email protected]','111-222-3333');

insert into mybatis_one2many_classes
(one2many_name,one2many_description,one2many_person_ids) values
('JavaSE','JavaSE',1);

insert into mybatis_one2many_classes
(one2many_name,one2many_description,one2many_person_ids) values
('JavaEE','JavaEE',2);

insert into mybatis_one2many_classes
(one2many_name,one2many_description,one2many_person_ids) values
('MyBatis','MyBatis',1);

classesには複数のpersonが含まれており、テーブルが作成され、データ挿入にはpersonテーブルとpersonデータがあることを確認する必要があります

2.2、javaエンティティの作成

get,setメソッド省略

public class One2manyPerson {
    private int personId;
    private String personName;
    private String personEmail;
    private String personPhone;
}
public class One2manyClasses {
    private int classId;
    private String className;
    private String classDescription;
    private Date startDate;
    private Date endDate;
    private List personList = new ArrayList();
}

classesには複数のpersonが含まれており、集合方式で体現されている

2.3、mapperマッピングファイルの作成
2.3.1、方式一:直接関連オブジェクト

classes取得personデータ直接resultMap方式取得

"one2manyMapper">
    id="one2manyPerson" type="com.demo.mybatis.one2many.One2manyPerson">
        <id property="personId" column="one2many_person_id"/>
        <result property="personName" column="one2many_name"/>
        <result property="personEmail" column="one2many_email"/>
        <result property="personPhone" column="one2many_phone"/>
    


    id="one2manyClasses" type="com.demo.mybatis.one2many.One2manyClasses">
        <id property="classId" column="one2many_classes_id"/>
        <result property="className" column="one2many_name"/>
        <result property="classDescription" column="one2many_description"/>
        <result property="startDate" column="one2many_start_date"/>
        <result property="endDate" column="one2many_end_date"/>
        property="personList" resultMap="one2manyPerson"/>
    

    id="selectClasses" parameterType="int" resultMap="one2manyClasses">
        select * from mybatis_one2many_classes classes
        left outer join mybatis_one2many_person
         on classes.one2many_person_ids = mybatis_one2many_person.one2many_person_id
        where classes.one2many_classes_id =#{classId}
    

2.3.2、方式二:間接関連

classes関連personデータはsqlクエリー方式で取得

"one2manyMapper2">
    id="one2manyPerson" type="com.demo.mybatis.one2many.One2manyPerson">
        <id property="personId" column="one2many_person_id"/>
        <result property="personName" column="one2many_name"/>
        <result property="personEmail" column="one2many_email"/>
        <result property="personPhone" column="one2many_phone"/>
    

    id="selectPerson" resultMap="one2manyPerson" parameterType="int">
        select * from mybatis_one2many_person where one2many_person_id =#{personId}
    

    id="one2manyClasses" type="com.demo.mybatis.one2many.One2manyClasses">
        <id property="classId" column="one2many_classes_id"/>
        <result property="className" column="one2many_name"/>
        <result property="classDescription" column="one2many_description"/>
        <result property="startDate" column="one2many_start_date"/>
        <result property="endDate" column="one2many_end_date"/>
        property="personList" column="one2many_person_ids" select="selectPerson"/>
    

    id="selectClasses" parameterType="int" resultMap="one2manyClasses">
        select * from mybatis_one2many_classes
        where one2many_classes_id =#{classId}
    

2.4、テスト:データ取得

    @Test
    public void selectClasses(){
        SqlSession session = SessionUtis.getSession();
      One2manyClasses classes =  session.selectOne("one2manyMapper.selectClasses",1);
        System.out.println(classes.toString());
    }
    @Test
    public void selectClasses2(){
        SqlSession session = SessionUtis.getSession();
        One2manyClasses classes = session.selectOne("one2manyMapper2.selectClasses",1);
        System.out.println(classes.toString());
    }

採用方式1と方式2は同じ効果ですが、mapper書き方の違い

三、多対多

1つのcartオブジェクトが複数のstudentオブジェクトを含む

1つのstudentオブジェクトが複数のcartオブジェクトを含む

cartにはstudentセットが含まれ、studentにはcartセットが含まれている

cartのidに対応するstudentのid

を含む中間テーブルを採用
3.1、データベース表の作成

create table mybatis_many2many_cart (
   many2many_cart_id int(3) auto_increment not null primary key,
   many2many_cart_code varchar(50) not null,
   many2many_cart_name varchar(50) not null);

create table mybatis_many2many_student (
   many2many_student_id int(3) auto_increment not null primary key,
   many2many_name varchar(50) not null,
   many2many_gender varchar(50) ,
   many2many_major varchar(50) ,
   many2many_grade varchar(50));

create table mybatis_many2many_other (
  many2many_other_id  int(3) auto_increment not null primary key,
  many2many_student_id int references mybatis_many2many_student(many2many_student_id),
  many2many_cart_id int references mybatis_many2many_cart(many2many_cart_id));


insert into mybatis_many2many_cart
(many2many_cart_name,many2many_cart_code) values
('JavaSE',1);
insert into mybatis_many2many_cart
(many2many_cart_name,many2many_cart_code) values
('JavaEE',2);
insert into mybatis_many2many_cart
(many2many_cart_name,many2many_cart_code) values
('MyBatis',1);

insert into mybatis_many2many_student
(many2many_name,many2many_gender,many2many_major,many2many_grade)
 values('John','johncom','1890','123-7890');
insert into mybatis_many2many_student
(many2many_name,many2many_gender,many2many_major,many2many_grade)
values('Paul','paulcom','111-333','123-90');

insert into mybatis_many2many_other(many2many_student_id,many2many_cart_id)values(1,1);
insert into mybatis_many2many_other(many2many_student_id,many2many_cart_id)values(1,2);
insert into mybatis_many2many_other(many2many_student_id,many2many_cart_id)values(1,3);
insert into mybatis_many2many_other(many2many_student_id,many2many_cart_id)values(2,1);
insert into mybatis_many2many_other(many2many_student_id,many2many_cart_id)values(2,2);
insert into mybatis_many2many_other(many2many_student_id,many2many_cart_id)values(2,3);

中間テーブルother作成およびデータ挿入に必要なcartおよびstudentの作成および挿入

3.2、javaエンティティオブジェクトの作成

get,setメソッドを省略

public class Many2manyCart {
    private int cartId;
    private String carCode;
    private String cartName;
    private List studentList = new ArrayList();
}
public class Many2manyStudent {
    private int stuId;
    private String stuName;
    private String stuGender;
    private String stuMajor;
    private String stuGrade;
    private List cartList = new ArrayList();
}

複数のオブジェクトを集合で実現

3.3、mapperプロファイルの作成

"many2manyMapper">

    id="many2manyStudent" type="com.demo.mybatis.many2many.Many2manyStudent">
        <id property="stuId" column="many2many_student_id"/>
        <result property="stuName" column="many2many_name"/>
        <result property="stuGender" column="many2many_gender"/>
        <result property="stuMajor" column="many2many_major"/>
        <result property="stuGrade" column="many2many_grade"/>
    
    id="many2manyCart" type="com.demo.mybatis.many2many.Many2manyCart">
        <id property="cartId" column="many2many_cart_id"/>
        <result property="carCode" column="many2many_cart_code"/>
        <result property="cartName" column="many2many_cart_name"/>
    

    id="otherStudent" type="com.demo.mybatis.many2many.Many2manyStudent" extends="many2manyStudent">
        property="cartList" resultMap="many2manyCart"/>
    

    id="otherCart" type="com.demo.mybatis.many2many.Many2manyCart" extends="many2manyCart">
        property="studentList" resultMap="many2manyStudent"/>
    

    id="selectStudent" parameterType="int" resultMap="otherStudent">
        select * from
        mybatis_many2many_cart cart,mybatis_many2many_student student ,mybatis_many2many_other other

        where
          student.many2many_student_id = #{stuId}
        and
          student.many2many_student_id = other.many2many_student_id
        and
          other.many2many_cart_id = cart.many2many_cart_id
    


    id="selectCart" parameterType="int" resultMap="otherCart">
        select * from
        mybatis_many2many_cart cart,mybatis_many2many_student student ,mybatis_many2many_other other

        where
          cart.many2many_cart_id = #{cartId}
        and
           cart.many2many_cart_id = other.many2many_cart_id
        and
          other.many2many_student_id = student.many2many_student_id
    

otherCart:cartの中間テーブルを移動し、collectionを介してstudent

を導入する

selectCart:パラメータotherCartを返します.otherCartを複数のオブジェクトに再アセンブリする必要があります

3.4、テスト:データ使用

    @Test
    public void selectStudent() {
        SqlSession session = SessionUtis.getSession();
        List student = session.selectList("many2manyMapper.selectStudent", 1);
        System.out.println(student.toString());
    }

    @Test
    public void selectCart() {
        SqlSession session = SessionUtis.getSession();
        List carts = session.selectList("many2manyMapper.selectCart", 1);
        System.out.println(carts.toString());
    }

コード:
https://github.com/brusion/brusion-code/tree/master/demo-java/04%20-%20demo%20-%20mybatis/mybatis-04