Mybatis basics: CRUD, fuzzy query, multi-condition query

Mybatis basic addition, deletion, modification, fuzzy query, multi-condition query

1. Create a new test database and create it according to the attributes of the entity class

2. Entity class

package com.entity;

/**
 * Database entity class
 * Created by lvjun on 2018-04-12.
 */
public class Category {
    private int id;
    private String name;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    //display Chinese
    @Override
    public String toString() {
        return "Category{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

3. Configuration file Category.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.entity">
    <!--List-->
    <select id="listCategory" resultType="Category">
        select * from   category
    </select>
    <!--delete-->
    <delete id="deleteCategory" parameterType="Category">
        delete from category where id= #{id}
    </delete>
    <!--Query a single -->
    <select id="getCategory" parameterType="_int" resultType="Category">
        select * from   category  where id= #{id}
    </select>
    <!--Modify-->
    <update id="updateCategory" parameterType="Category">
        update category set name=#{name} where id=#{id}
    </update>
    <!--Add-->
    <insert id="addCategory" parameterType="Category">
        insert into category ( name ) values (#{name})
    </insert>
    <!--Fuzzy query-->
    <select id="listCategoryByName" parameterType="string" resultType="Category">
        select * from   category  where name like concat('%',#{0},'%')
    </select>
    <!--Multi-condition query-->
    <select id="listCategoryByIdAndName" resultType="Category">
        select * from category
        <where>
            <if test="id!=null">
                and id > #{id}
            </if>
            <if test="name!=null">
                and name like concat('%',#{name},'%')
            </if>
        </where>
    </select>

</mapper>

4. Configuration file mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
    <typeAliases>
        <package name="com.entity"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/school?characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="1234"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="Category.xml"/>
    </mappers>
</configuration>

5. Test class

package com.lvjun;


import com.entity.Category;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;


/**
 * Query list
 * Created by lvjun on 2018-04-12.
 */
public class TestSelectList {

    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        List<Category> cs = session.selectList("listCategory");
        for (Category c : cs) {
            System.out.println(c.getId()+"  "+c.getName());
         }

    }
}

package com.lvjun;

import com.entity.Category;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * Query a record
 * Created by lvjun on 2018-04-12.
 */
public class TestSelectOne {

    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        Category c = session.selectOne("getCategory", 3);
        System.out.println(c.getId()+"  "+c.getName());
        session.commit();
        session.close();

    }

}

package com.lvjun;

import com.entity.Category;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * Fuzzy query
 * Created by lvjun on 2018-04-12.
 */
public class TestSelectLike {

    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        List<Category> cs = session.selectList("listCategoryByName", "win");
        for (Category c : cs) {
            System.out.println(c.getId()+"  "+c.getName());
        }

        session.commit();
        session.close();

    }

}

package com.lvjun;

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.entity.Category;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

/**
 * Multi-condition query
 * Created by lvjun on 2018-04-12.
 */
public class TestSelectToLike {
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        Map<String, Object> params = new HashMap<>();
        params.put("id", 3); //conditional query
        params.put("name", "wi");

        List<Category> cs = session.selectList("listCategoryByIdAndName", params);
        for (Category c : cs) {
            System.out.println(c.getId()+"  "+c.getName());
        }

        session.commit();
        session.close();

    }
}

package com.lvjun;

import com.entity.Category;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;


/**
 * Modify the record
 * Created by lvjun on 2018-04-12.
 */
public class TestUpdate {
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        Category c = session.selectOne("getCategory", 2);
        c.setName("Android 8");
        session.update("updateCategory", c);

        listAll(session);

        session.commit();
        session.close();

    }

    private static void listAll(SqlSession session) {
        List<Category> cs = session.selectList("listCategory");
        for (Category c : cs) {
            System.out.println(c.getId()+"  "+c.getName());
        }
    }
}

package com.lvjun;

import com.entity.Category;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * insert a record
 * Created by lvjun on 2018-04-12.
 */
public class TestInsert {
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        Category c = new Category();
        c.setName("Newly added data");
        session.insert("addCategory", c);

        listAll(session);

        session.commit();
        session.close();

    }

    private static void listAll(SqlSession session) {
        List<Category> cs = session.selectList("listCategory");
        for (Category c : cs) {
            System.out.println(c.getId()+"  "+c.getName());
        }
    }
}

package com.lvjun;

import com.entity.Category;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * delete a record
 * Created by lvjun on 2018-04-12.
 */
public class TestDeleteOne {
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();

        Category c = new Category();
        c.setId(6);
        session.delete("deleteCategory", c);

        listAll(session);

        session.commit();
        session.close();

    }

    private static void listAll(SqlSession session) {
        List<Category> cs = session.selectList("listCategory");
        for (Category c : cs) {
            System.out.println(c.getId()+"  "+c.getName());
        }
    }

}