SoFunction
Updated on 2025-05-20

Several ways to keep the values ​​and ids of other fields consistent when mybatisPlus is added

When adding new onessp_id_pathAutomatic andidTo maintain consistency, it is necessary to handle the corresponding process in the entity class and insertion logic. MyBatis-Plus provides several ways to achieve this requirement:

Solution 1: Use MyBatis-Plus' autofill function

This is the most elegant solution, by implementingMetaObjectHandlerInterface, automatically set before insertionsp_id_pathValue:

import ;
import ;
import ;
import ;

@Component
public class MyMetaObjectHandler implements MetaObjectHandler {

    @Override
    public void insertFill(MetaObject metaObject) {
        // Get the current entity object        Object entity = ();
        
        // Only handle DsteSpConfigNew entity        if (entity instanceof DsteSpConfigNew) {
            DsteSpConfigNew config = (DsteSpConfigNew) entity;
            
            // If sp_id_path is not set manually, it is set to the id value before insertion            if (() == null) {
                // Note: The id may not have been generated yet and requires special processing                // The following will provide specific implementation methods            }
        }
    }

    @Override
    public void updateFill(MetaObject metaObject) {
        // Update the fill logic    }
}

Solution 2: Update sp_id_path after insertion

becauseidIt is a self-increment primary key, which cannot be obtained before insertion, and can be implemented in two steps:

  • Insert the record first to get the generatedid
  • Update nowsp_id_pathFor thisid 
@Service
public class DsteSpConfigNewService {

    @Autowired
    private DsteSpConfigNewMapper configMapper;

    @Transactional
    public void saveConfig(DsteSpConfigNew config) {
        // 1. Insert the record, the id will be automatically generated at this time        (config);
        
        // 2. Get the generated id        Long id = ();
        
        // 3. Update sp_id_path to id value        DsteSpConfigNew updateEntity = new DsteSpConfigNew();
        (id);
        ((id));
        
        (updateEntity);
    }
}

Solution 3: Use database triggers (recommended)

Database-level triggers can be more reliable to ensuresp_id_pathandidConsistency:

DELIMITER $$
CREATE TRIGGER after_dste_sp_config_new_insert
AFTER INSERT ON dste_sp_config_new
FOR EACH ROW
BEGIN
    -- Will record the new sp_id_path Updated to id value
    UPDATE dste_sp_config_new 
    SET sp_id_path =  
    WHERE id = ;
END$$
DELIMITER ;

This method does not require modifying Java code and is completely automatically processed by the database, but attention should be paid to the performance impact of triggers.

Entity configuration

Make sure that the entity class contains these two fields and use the correct annotation:

import ;
import ;
import ;

@Data
@TableName("dste_sp_config_new")
public class DsteSpConfigNew {

    @TableId(type = )
    private Long id;
    
    private String spName;
    
    private Long projectId;
    
    private String spIdPath;
    
    private String spNamePath;
    
    private Long parentSpId;
    
    private Integer spStatus;
    
    private LocalDateTime createAt;
    
    private LocalDateTime updateAt;
    
    private LocalDateTime deleteAt;
}

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