mybatis-flex/readme.md

Mybatis-Flex is an elegant Mybatis Enhancement Framework.

Features

• 1、Mybatis-Flex is very lightweight, and it only depends on Mybatis and no other third-party dependencies
• 2、Basic CRUD operator and paging query of Entity class
• 3、Row mapping support, you can add, delete, modify and query the database without entity classes
• 4、Support multiple databases, and expand through dialects flexibly.
• 5、Support combined primary keys and different primary key content generation strategies
• 6、Extremely friendly SQL query, IDE automatically prompts and no worries about mistakes
• 7、More little surprises

hello world

step 1: write entity class

@Table("tb_account")
public class Account {

    @Id()
    private Long id;
    private String userName;
    private Date birthday;
    private int sex;

    //getter setter
}

step 2: write mapper class(it needs extends BaseMapper)

public interface AccountMapper extends BaseMapper<Account> {
    //only Mapper interface define.
}

step 3: start query data

e.g. 1： query by primary key

class HelloWorld {
    public static void main(String... args) {

        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/mybatis-flex");
        dataSource.setUsername("username");
        dataSource.setPassword("password");

        MybatisFlexBootstrap.getInstance()
                .setDatasource(dataSource)
                .addMapper(AccountMapper.class)
                .start();


        //id=100
        Account account = MybatisFlexBootstrap.getInstance()
                .execute(AccountMapper.class, mapper ->
                        mapper.selectOneById(100)
                );
    }
}

e.g.2: query list

class HelloWorld {
    public static void main(String... args) {

        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/mybatis-flex");
        dataSource.setUsername("username");
        dataSource.setPassword("password");

        MybatisFlexBootstrap.getInstance()
                .setDatasource(dataSource)
                .addMapper(AccountMapper.class)
                .start();

        //use QueryWrapper to build query conditions
        QueryWrapper query = QueryWrapper.create()
                .select()
                .from(ACCOUNT)
                .where(ACCOUNT.ID.ge(100))
                .and(ACCOUNT.USER_NAME.like("zhang").or(ACCOUNT.USER_NAME.like("li")));

        // execute SQL：
        // ELECT * FROM `tb_account`
        // WHERE `tb_account`.`id` >=  100
        // AND (`tb_account`.`user_name` LIKE '%zhang%' OR `tb_account`.`user_name` LIKE '%li%' )
        List<Account> accounts = MybatisFlexBootstrap.getInstance()
                .execute(AccountMapper.class, mapper ->
                        mapper.selectListByQuery(query)
                );

    }
}

e.g.3: paging query

class HelloWorld {
    public static void main(String... args) {

        HikariDataSource dataSource = new HikariDataSource();
        dataSource.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/mybatis-flex");
        dataSource.setUsername("username");
        dataSource.setPassword("password");

        MybatisFlexBootstrap.getInstance()
                .setDatasource(dataSource)
                .addMapper(AccountMapper.class)
                .start();

        //use QueryWrapper to build query conditions
        QueryWrapper query = QueryWrapper.create()
                .select()
                .from(ACCOUNT)
                .where(ACCOUNT.ID.ge(100))
                .and(ACCOUNT.USER_NAME.like("zhang").or(ACCOUNT.USER_NAME.like("li")))
                .orderBy(ACCOUNT.ID.desc());

        // execute SQL：
        // ELECT * FROM `tb_account`
        // WHERE `tb_account`.`id` >=  100
        // AND (`tb_account`.`user_name` LIKE '%zhang%' OR `tb_account`.`user_name` LIKE '%li%' )
        // ORDER BY `tb_account`.`id` DESC
        // LIMIT 40,10
        Page<Account> accountPage = MybatisFlexBootstrap.getInstance()
                .execute(AccountMapper.class, mapper ->
                        mapper.paginate(5, 10, query)
                );

    }
}

QueryWrapper Samples

select *

QueryWrapper query=new QueryWrapper();
query.select().from(ACCOUNT)

// SQL: 
// SELECT * FROM tb_account

select columns

QueryWrapper query=new QueryWrapper();
query.select(ACCOUNT.ID,ACCOUNT.USER_NAME).from(ACCOUNT)

// SQL: 
// SELECT tb_account.id, tb_account.user_name 
// FROM tb_account

QueryWrapper query=new QueryWrapper();
query.select(ACCOUNT.ALL_COLUMNS).from(ACCOUNT)

// SQL: 
// SELECT tb_account.id, tb_account.user_name, tb_account.birthday, 
// tb_account.sex, tb_account.is_normal 
// FROM tb_account

select functions

 QueryWrapper query=new QueryWrapper()
        .select(
            ACCOUNT.ID,
            ACCOUNT.USER_NAME,
            max(ACCOUNT.BIRTHDAY),
            avg(ACCOUNT.SEX).as("sex_avg")
        ).from(ACCOUNT);

// SQL: 
// SELECT tb_account.id, tb_account.user_name, 
// MAX(tb_account.birthday), 
// AVG(tb_account.sex) AS sex_avg 
// FROM tb_account

where

QueryWrapper queryWrapper=QueryWrapper.create()
    .select()
    .from(ACCOUNT)
    .where(ACCOUNT.ID.ge(100))
    .and(ACCOUNT.USER_NAME.like("michael"));

// SQL: 
// SELECT * FROM tb_account 
// WHERE tb_account.id >=  ?  
// AND tb_account.user_name LIKE  ? 

exists, not exists

QueryWrapper queryWrapper=QueryWrapper.create()
    .select()
    .from(ACCOUNT)
    .where(ACCOUNT.ID.ge(100))
    .and(
        exist(
            selectOne().from(ARTICLE).where(ARTICLE.ID.ge(100))
        )
    );

// SQL: 
// SELECT * FROM tb_account 
// WHERE tb_account.id >=  ?  
// AND EXIST (
// SELECT 1 FROM tb_article WHERE tb_article.id >=  ? 
// )

and (...) or (...)

QueryWrapper queryWrapper=QueryWrapper.create()
    .select()
    .from(ACCOUNT)
    .where(ACCOUNT.ID.ge(100))
    .and(ACCOUNT.SEX.eq(1).or(ACCOUNT.SEX.eq(2)))
    .or(ACCOUNT.AGE.in(18,19,20).or(ACCOUNT.USER_NAME.like("michael")));

// SQL: 
// SELECT * FROM tb_account 
// WHERE tb_account.id >=  ?  
// AND (tb_account.sex =  ?  OR tb_account.sex =  ? ) 
// OR (tb_account.age IN (?,?,?) OR tb_account.user_name LIKE  ? )

group by

QueryWrapper queryWrapper=QueryWrapper.create()
    .select()
    .from(ACCOUNT)
    .groupBy(ACCOUNT.USER_NAME);

// SQL: 
// SELECT * FROM tb_account 
// GROUP BY tb_account.user_name

having

QueryWrapper queryWrapper=QueryWrapper.create()
    .select()
    .from(ACCOUNT)
    .groupBy(ACCOUNT.USER_NAME)
    .having(ACCOUNT.AGE.between(18,25));

// SQL: 
// SELECT * FROM tb_account 
// GROUP BY tb_account.user_name 
// HAVING tb_account.age BETWEEN  ? AND ?

join

QueryWrapper queryWrapper = QueryWrapper.create()
    .select()
    .from(ACCOUNT)
    .leftJoin(ARTICLE).on(ACCOUNT.ID.eq(ARTICLE.ACCOUNT_ID))
    .where(ACCOUNT.AGE.ge(10));

// SQL: 
// SELECT * FROM tb_account 
// LEFT JOIN tb_article 
// ON tb_account.id = tb_article.account_id 
// WHERE tb_account.age >=  ? 

Questions？

1、how to generate "ACCOUNT" class for QueryWrapper by Account.java ?

build the project by IDE, or execute maven build command: mvn clean package

More Samples

• 1、Mybatis-Flex Only (Native)
• 2、Mybatis-Flex with Spring
• 3、Mybatis-Flex with Spring boot