Receiving Data Too Long for column

I'm working with a Spring Boot application using JPA and Hibernate, and I'm trying to persist a field that is serialized as JSON using a custom @Converter. The field is mapped to a varchar(2000) column in MySQL.
DTO:

@XmlElement
private Object value;

Entity:

@Column(name = "value")
@Convert(converter = JpaConverterJson.class)
private Object value;

Converter:

@Component
@Converter
@Slf4j
public class JpaConverterJson implements AttributeConverter<Object, String> {

    @Autowired
    private ObjectMapper objectMapper;

    @Override
    public String convertToDatabaseColumn(Object meta) {
        try {
            objectMapper.disable(SerializationFeature.WRAP_ROOT_VALUE);
            return objectMapper.writeValueAsString(meta);
        } catch (JsonProcessingException ex) {
            log.error("JsonProcessingException encoding Object into String: {}", ex.getMessage());
            return null;
        }
    }

    @Override
    public Object convertToEntityAttribute(String dbData) {
        try {
            return objectMapper.readValue(dbData, Object.class);
        } catch (IOException ex) {
            log.error("IOException decoding json from database: {}", ex.getMessage());
            return null;
        }
    }
}

Issue:

When I run a native SQL INSERT query, the data gets stored correctly.

But when I persist the entity using JPA, I get this error:

com.mysql.cj.jdbc.exceptions.MysqlDataTruncation: Data truncation: Data too long for column 'value' at row 1

Why does Hibernate fail to persist the data when the native SQL works?

Solution

Before persisting the JSON string, Hibernate validates its length against the defined column size (e.g., VARCHAR(2000)). If the content exceeds this limit, it throws a Data too long for column exception. In contrast, native SQL operations may silently truncate the data or bypass length validation altogether.

Use LONGTEXT to handle large JSON:

@Column(name = "value", columnDefinition = "LONGTEXT")
@Convert(converter = JpaConverterJson.class)
private Object value;

And update the column in MySQL:

[LONGTEXT avoids size issues for large JSON data]

ALTER TABLE your_table MODIFY COLUMN value LONGTEXT;

I hope your problem is solved.