JPA DAO Update row without full row context

Question

Have a table with >70 columns.

I use about 8 of these columns with the .java object, including the id - not sure if that matters.

My Id column has the following:

@Column(name = "pseudonym", nullable = false)
@Basic(fetch = FetchType.EAGER)
@Id

My question is this:

If I want to update a row using xxxDAO.store(updatedRow) - do I need to specify anything to reference the row ID or am I missing something here?

I'm getting the following exception:

DEBUG: org.springframework.web.servlet.DispatcherServlet - Could not complete request
javax.persistence.PersistenceException: org.hibernate.exception.DataException: Could not execute JDBC batch update
.. ~(adding this in here)~ not a valid month

Hopefully I have explained this well enough. Let me know if I haven't.

Thanks in advance

Some pseudo code for reference:

item = dao.getItemById(123);
item.setUpdateTime(theTime);
dao.store(item);

Store: return getEntityManager().merge(itemToStore);

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To Clarify

I was getting the exception above not a valid month. This was because I was trying to update an Oracle table that had a column defined as a timestamp. I was trying to pass a String value (even though the String was essentially structured identically).

In an attempt to debug this, my question was if I could update a row via the JPA DAO without having e.g. all 70+ columns defined in my Java object. This turned out to be possible and the exception was not related to not having defined columns. The exception was simply because the timestamp I was trying to update didn't have the correct structure. I changed the Strings to Date objects, and they updated

Answer 1

My question was this:

If I want to update a row using xxxDAO.store(updatedRow) - do I need to specify anything to reference the row ID or am I missing something here?

Answer

No - It is managed automatically, you don't need to specify an identifier, and you don't need to create all references for all the columns in the table either in your java object.

item = dao.getItemById(123); // get item from dao in the database
item.setUpdateTime(theTime); // set/or change a value
dao.store(item); // contains merge(), and subsequently flush()

item contains the reference to what row will be updated.

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Additionally, when dealing with timestamps in your sql table, ensure that all are actual Date objects and not Strings.

When pulling the date as a String for read only is fine. But if you want to update this row in the future via a merge, the String will not work. The value for the date will be re-passed again (as a String), and cause an exception to be thrown (e.g. not a valid month). Ensure your dates/timestamps are stored as Date objects as opposed to Strings and perhaps toString them on your UI.