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JPA Map Card

I have a data structure that boils down to:

class StylesheetUserPreferencesImpl {
    long id;
    String desc;
    Map<String, Map<String, String>> nodeAttributes;
}

To try to make JPA2 annotations a little smarter, I created a small class to represent the inner class:

class LayoutAttributeImpl {
    String nodeId;
    private Map<String, String> attributes;
}

What gives me:

class StylesheetUserPreferencesImpl {
    long id;
    String desc;
    Map<String, LayoutAttributeImpl> nodeAttributes;
}

In the end, I would like the table structure to look like this:

SS_USER_PREFS
    PREFS_ID
    DESC

SS_LAYOUT_ATTRS
    PREFS_ID
    NODE_ID
    NAME
    VALUE

I'm not quite sure how to do this, for example, in JPA. It looks like I want LayoutAttributeImpl to be nested, but as I understand it, Embeddable objects cannot contain collections. I am working right now with LayoutAttributeImpl, acting as a full-fledged @Entity, but this gives me an extra table that I really don't need.

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1 answer

How about something like:

class StylesheetUserPreferencesImpl {
    long id;
    String desc;
    Map<AttributeCoordinate, String> attributes;
}

class AttributeCoordinate {
    String nodeID;
    String prefID;
}

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