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package cayenne.tutorial;
import java.util.Calendar;
import java.util.Collections;
import java.util.GregorianCalendar;
import java.util.List;
import org.apache.cayenne.DataObjectUtils;
import org.apache.cayenne.access.DataContext;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.exp.ExpressionFactory;
import org.apache.cayenne.query.NamedQuery;
import org.apache.cayenne.query.QueryChain;
import org.apache.cayenne.query.SelectQuery;
public class Main {
public static void main(String[] args) {
DataContext context = DataContext.createDataContext();
// cleans up all data, so that we start with empty database on each tutorial run
mappingQueriesChapter(context);
// persists an artist, a gallery and a few paintings
dataObjectsChapter(context);
// selects previously saved data
selectQueryChapter(context);
// deletes objects
deleteChapter(context);
}
static void dataObjectsChapter(DataContext context) {
Artist picasso = (Artist) context.newObject(Artist.class);
picasso.setName("Pablo Picasso");
picasso.setDateOfBirthString("18811025");
Gallery metropolitan = (Gallery) context.newObject(Gallery.class);
metropolitan.setName("Metropolitan Museum of Art");
Painting girl = (Painting) context.newObject(Painting.class);
girl.setName("Girl Reading at a Table");
Painting stein = (Painting) context.newObject(Painting.class);
stein.setName("Gertrude Stein");
picasso.addToPaintings(girl);
picasso.addToPaintings(stein);
girl.setGallery(metropolitan);
stein.setGallery(metropolitan);
context.commitChanges();
}
static void mappingQueriesChapter(DataContext context) {
QueryChain chain = new QueryChain();
chain.addQuery(new NamedQuery("DeleteAll", Collections.singletonMap(
"table",
"PAINTING")));
chain.addQuery(new NamedQuery("DeleteAll", Collections.singletonMap(
"table",
"ARTIST")));
chain.addQuery(new NamedQuery("DeleteAll", Collections.singletonMap(
"table",
"GALLERY")));
context.performGenericQuery(chain);
}
static void selectQueryChapter(DataContext context) {
// select all paintings
SelectQuery select1 = new SelectQuery(Painting.class);
List paintings1 = context.performQuery(select1);
// select paintings that start with "Gi*"
Expression qualifier2 = ExpressionFactory.likeIgnoreCaseExp(
Painting.NAME_PROPERTY,
"gi%");
SelectQuery select2 = new SelectQuery(Painting.class, qualifier2);
List paintings2 = context.performQuery(select2);
// select all paintings done by artists who were born more than a 100 years ago
Calendar c = new GregorianCalendar();
c.set(c.get(Calendar.YEAR) - 100, 0, 1, 0, 0, 0);
Expression qualifier3 = Expression.fromString("artist.dateOfBirth < $date");
qualifier3 = qualifier3.expWithParameters(Collections.singletonMap("date", c
.getTime()));
SelectQuery select3 = new SelectQuery(Painting.class, qualifier3);
List paintings3 = context.performQuery(select3);
}
static void deleteChapter(DataContext context) {
Expression qualifier = ExpressionFactory.matchExp(
Artist.NAME_PROPERTY,
"Pablo Picasso");
SelectQuery select = new SelectQuery(Artist.class, qualifier);
Artist picasso = (Artist) DataObjectUtils.objectForQuery(context, select);
if (picasso != null) {
context.deleteObject(picasso);
context.commitChanges();
}
}
}