chisel out the structure of the update methods

hex_repo/examples/hex/repo/examples/HexRepoExamples.java

@@ -1,16 +1,32 @@
 package hex.repo.examples;
 
+import hex.ql.Query;
 import hex.repo.test.Person;
 import hex.repo.test.PersonRepository;
 import hex.repo.Repository;
+import hex.repo.RepositoryBase;
+import hex.repo.sql.test.Book;
 
 import static hex.ql.QueryLanguage.*;
 
 public class HexRepoExamples {
     public static void main(String[] args) {
+        basicQuery();
+
+        bulkUpdate();
+    }
+
+    private static void basicQuery() {
         Repository<Person> people = new PersonRepository();
 
         from(people).where(Person::getLastName, is("Newton"))
                 .forEach((p) -> System.out.println(p.getFullName()));
     }
+
+    private static void bulkUpdate() {
+        Repository<Book> repo = new RepositoryBase<>(Book.class);
+
+        Query<Book> books = from(repo).where(Book::getPublishedYear, is(2114));
+        repo.update(books, b -> b.setPublishedYear(2014));
+    }
 }

hex_repo/src/hex/repo/AbstractRepository.java

@@ -1,21 +1,22 @@
 package hex.repo;
 
+import hex.ql.Query;
+import hex.ql.Queryable;
 import hex.ql.ast.InvalidAstException;
+import hex.ql.ast.predicates.EqualityPredicate;
 import hex.repo.metadata.DataMappingException;
 import hex.repo.metadata.Metadata;
 import hex.repo.sql.PreparedSqlQuery;
 import hex.repo.streams.RepositoryStream;
-import hex.ql.Queryable;
-import hex.ql.ast.predicates.EqualityPredicate;
 
 import java.sql.Connection;
-import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
+import java.util.function.Consumer;
+import java.util.function.Function;
 
 /**
  * Created by jason on 14-11-05.
@@ -59,6 +60,23 @@ public List<T> executeQuery(PreparedSqlQuery query) {
         return executeQuery(query, ResultSetMapper.toList(get_metadata()::mapRecord));
     }
 
+    @Override
+    public void update(Query<T> queryToUpdate, Consumer<T> updateDescriptor) {
+        if(queryToUpdate instanceof RepositoryStream) {
+            ((RepositoryStream<T>) queryToUpdate).update(updateDescriptor);
+        } else {
+            // TODO: Log INFO about performance of this
+            queryToUpdate.forEach(updateDescriptor.andThen(this::update));
+        }
+    }
+
+    @Override
+    public void update(T t) {
+        Function<T, Integer> primaryKey = get_metadata().getPrimaryKey();
+        RepositoryStream<T> stream = (RepositoryStream<T>) stream().where(primaryKey, new EqualityPredicate<>(primaryKey.apply(t)));
+        stream.update(t);
+    }
+
     @Override
     public Iterator<T> iterator() {
         return stream().iterator();

hex_repo/src/hex/repo/Repository.java

@@ -1,9 +1,11 @@
 package hex.repo;
 
+import hex.ql.Query;
 import hex.ql.Queryable;
 import hex.repo.streams.RepositoryStream;
 
 import java.util.Optional;
+import java.util.function.Consumer;
 
 /**
  * Created by jason on 14-11-01.
@@ -12,4 +14,8 @@ public interface Repository<T> extends Queryable<T> {
     Optional<T> find(int id);
 
     RepositoryStream<T> stream();
+
+    void update(Query<T> queryToUpdate, Consumer<T> updateDescriptor);
+
+    void update(T t);
 }

hex_repo/src/hex/repo/streams/RepositoryStream.java

@@ -170,7 +170,7 @@ public <R> Query<R> map(Function<? super T, ? extends R> mapper) {
      * this stream with the contents of a mapped stream produced by applying
      * the provided mapping function to each element.
      *
-     * This is effectively this is an inner join to a one-to-many relationship in a
+     * This is effectively an inner join to a one-to-many relationship in a
      * relational database.
      * <p>
      * <p>This is an <a href="package-summary.html#StreamOps">intermediate
@@ -440,4 +440,23 @@ public Query<T> unordered() {
         dup.orderBy = null;
         return dup;
     }
+
+    /**
+     * Converts this stream into an update statement that makes the changes caused by
+     * {@code updateDescriptor} to the records currently described by this {@link RepositoryStream}.
+     * @param updateDescriptor A consumer that describes the changes to be made
+     */
+    public void update(Consumer<T> updateDescriptor) {
+
+    }
+
+    /**
+     * Update the record {@code t} if it exists with all the values found in {@code t}.
+     * @param t Record values to save to the database
+     * @throws hex.repo.RepositoryException If the record does not exist or an error occurred during update
+     */
+    public void update(T t) {
+        // use the metadata to generate the update statement
+        // create a query generating class similar to SqlQuery. Use dialects wherever possible (i.e.: everywhere)
+    }
 }