Java ORM ObjectiveSQL 之 MySQL 实战

第一步，引用Maven依赖：

<dependency>
    <groupId>com.github.braisdom</groupId>
    <artifactId>objective-sql</artifactId>
    <version>1.3.4</version>
</dependency>

第二步，使用Annotation 定义一个DomainModel ：

import com.github.braisdom.objsql.annotations.Column;
import com.github.braisdom.objsql.annotations.DomainModel;
import com.github.braisdom.objsql.annotations.Queryable;
import com.github.braisdom.objsql.annotations.Relation;
import com.github.braisdom.objsql.relation.RelationType;

import java.util.List;

@DomainModel
public class Member {
    @Queryable
    @Column(updatable = false)
    private String no;

    @Queryable
    private String name;
    private Integer gender;
    private String mobile;
    private String otherInfo;

    @Relation(relationType = RelationType.HAS_MANY)
    private List<Order> orders;

}

第三步：定义ConnectionFactory 并注入ObjectiveSQL:

private static class MySQLConnectionFactory implements ConnectionFactory {

    @Override
    public Connection getConnection(String dataSourceName) throws SQLException {
        String url = "jdbc:mysql://localhost:4406/objective_sql?serverTimezone=Asia/Shanghai";
        String user = "root";
        String password = "123456";

        Connection connection;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver").newInstance();
            connection = DriverManager.getConnection(url, user, password);
        } catch (InstantiationException | IllegalAccessException | ClassNotFoundException ex) {
            throw new IllegalStateException(ex.getMessage(), ex);
        }
        return connection;
    }
}

Databases.installConnectionFactory(new MySQLConnectionFactory());

第四步：执行数据库操作
1) 创建会员

Member newMember = new Member();
newMember.setNo("100000")
        .setName("Pamela")
        .setGender(1)
        .setRegisteredAtWithJoda(DateTime.now())
        .setUpdatedAt(Timestamp.valueOf("2020-10-05 00:00:00"))
        .setMobile("15011112222");

Member member = Member.create(newMember, true); 

INSERT INTO `members` (`no`,`name`,`gender`,`mobile`,`extended_attributes`,`registered_at`,`updated_at`) 
VALUES (?,?,?,?,?,?,?), with: [100000,Pamela,1,15011112222,null,2020-10-08 11:01:57.368,2020-10-05 00:00:00.0]

2) 统计会员数量

long count = Member.count("id > ?", 10);

SELECT COUNT(*) AS count_rows FROM `members`

更多请访问：https://github.com/braisdom/ObjectiveSql