org.polypheny.jdbc.types.PolyDocument extends HashMap<String, TypedValue>. Use the normal Java map methods to read PolyDocument objects from a DocumentResult. A key can be absent or present with a Prism null value. Check containsKey and then the value’s isNull() to distinguish them. For a present nested document, call asDocument() on its TypedValue.
Constructors
| Constructor | Use |
|---|---|
PolyDocument() |
Creates an empty mutable map. |
PolyDocument(HashMap<String, TypedValue> entries) |
Copies the supplied map entries. |
PolyDocument(ProtoDocument document) |
Reads the entries from a document in the driver’s bundled Prism API. |
serialize() returns the corresponding Prism ProtoDocument. For Prism null values in a document you construct, use TypedValue.fromNull(). Changing a document in memory does not update its collection.
Reading a nested value
This standalone example constructs a document in memory and round-trips it through the Prism representation. It requires the JDBC JAR on the classpath and runs without a server.
import org.polypheny.jdbc.types.PolyDocument;
import org.polypheny.jdbc.types.TypedValue;
public class JdbcDocumentValueExample {
public static void main(String[] args) throws Exception {
PolyDocument address = new PolyDocument();
address.put("city", TypedValue.fromString("Basel"));
PolyDocument person = new PolyDocument();
person.put("address", TypedValue.fromDocument(address));
person.put("nickname", TypedValue.fromNull());
PolyDocument decoded = new PolyDocument(person.serialize());
System.out.println(decoded.get("address").asDocument().get("city").asString());
System.out.println(decoded.get("nickname").isNull());
System.out.println(decoded.containsKey("email"));
}
}
The example prints Basel, true, and false on separate lines.
