How to edit tinyblob date in mysql? - mysql

Question

I'm working on a legacy application with MySQL DB.
Here's the relevant table:
RESERVATION
============
id: int
creation_date: tinyblob
...other stuff...
When the entity is created, the creation_date is calculated using Java's LocalDate.now().
When I select the data from the table (in MySQL Workbench), I see only "BLOB" in the creation_date column. When I click "Open value in editor", I get something like:
’ sr
java.time.Ser]º"H² xpw àx
When I double click the field, nothing happens, it won't let me enter the editing mode.
Is there any way to directly edit the date stored like this? I could create a Java function that will insert some dates other than LocalDate.now(), but it would be easier to do this manually in the Workbench (or some other application). Since this is a legacy software, I'm not able to alter the column type.
Tnx.

Answer 1

Here is the solution. This guy helped me: https://stackoverflow.com/a/8504540/1177067
Create a new class which extends AttributeConverter:
import java.time.LocalDateTime;
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
#Converter(autoApply = true)
public class LocalDateTimeAttributeConverter implements AttributeConverter<LocalDateTime, Object> {
#Override
public Object convertToDatabaseColumn(LocalDateTime locDateTime) {
return locDateTime == null ? null : Timestamp.valueOf(locDateTime);
}
#Override
public LocalDateTime convertToEntityAttribute(Object sqlTimestamp) {
if (sqlTimestamp != null) {
try {
byte[] dbBytes = (byte[]) sqlTimestamp;
ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(dbBytes));
LocalDateTime covertedDateFromBytes = (LocalDateTime) ois.readObject();
ois.close();
return covertedDateFromBytes;
} catch (IOException ioe) {
ioe.printStackTrace();
} catch (ClassNotFoundException cnfe) {
cnfe.printStackTrace();
}
}
return null;
}
}
Be aware that:
#Override
public Object convertToDatabaseColumn(LocalDateTime locDateTime) {
return locDateTime == null ? null : Timestamp.valueOf(locDateTime);
}
is storing the date in a new way (as a Timestamp) so decide if you might want to go with the tinyblob further or use a new approach with Timestamp.