Prepare Work ​

Summary ​

Ngbatis provides two ways for developers to access nebula.

• Close to Mybatis-plus, providing a basic DAO to be extends, unnecessary to write any nGQL to operate single table, include vertex and edge. (See By Basic DAO for more details)
• Close to Mybatis, supporting developers to write complex nGQL or Cypher to finish read or write data. (See By Custom nGQL for more details)
• Based on entity objects, directly call the provided query method to complete direct data inspection. (See Entity Direct Query for details. You can skip the following preparations using this method)

Take Person 与 Like as examples.

Create Schema in Nebula (refer CREATE TAG、CREATE EDGE、CREATE INDEX) ​

CREATE tag `person` (
  `name` string NULL  , 
  `gender` string NULL  , 
  `height` double NULL ,
  `age` int NULL  , 
  `birthday` date NULL  
);

CREATE edge `like` (`likeness` double NULL  );

-- create index for query
CREATE TAG INDEX `i_person_name_age` on `person`(`name`(50), `age`);
CREATE TAG INDEX `i_person_name` on `person`(`name`(50));

Necessary POJO for two ways(By Basic DAO & By Custom nGQL) ​

Person.java ​

package your.domain;

import javax.persistence.Id;
import javax.persistence.Table;
import java.util.Date;
import lombok.Data;

@Data
@Table(name = "person")
public class Person {
    @Id
    private String name;
    private String gender;
    @ValueType(Double.class)
    private BigDecimal height;
    private Integer age;
    private Date birthday;
}

Like.java ​

package your.domain;

import lombok.Data;
import javax.persistence.Table;
import lombok.Data;

@Data
@Table(name = "like")
public class Like {
    private Double likeness;
}

LikeWithRank.java ​

package your.domain;

import javax.persistence.Id;
import javax.persistence.Table;
import lombok.Data;

@Table(name = "like")
public class LikeWithRank {
    @Id
    private Long rank;
    private Double likeness;
}

By now, the 'POJO' used in the two usage examples has been created. Let's start our coding journey.