ObjectiveSQL(Java ORM) 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:

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;
    }
}

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