Module io.ebean.api
Package io.ebean

Interface DtoQuery<T>

All Superinterfaces:
CancelableQuery
@NonNullApi public interface DtoQuery<T> extends CancelableQuery
Query for performing native SQL queries that return DTO Bean's.

These beans are just normal classes. They must have public constructors and setters.

Constructors with arguments are used if the number of constructor arguments matches the number of columns in the resultSet.

If the number of columns in the resultSet is greater than the largest constructor then the largest constructor is used for the first columns and remaining columns are mapped by setter methods. 



   // CustomerDto is just a 'bean like' class
   // with public constructor(s) and public setter methods

   String sql = "select id, name from customer where name like :name and status_code = :status";

   List<CustomerDto> beans =
     DB.findDto(CustomerDto.class, sql)
     .setParameter("name", "Acme%")
     .setParameter("status", "ACTIVE")
     .findList();

  • Method Details

    • findList

      List<T> findList()
      Execute the query returning a list.

    • findIterate

      QueryIterator<T> findIterate()
      Execute the query iterating a row at a time.

      Note that the QueryIterator holds resources related to the underlying resultSet and potentially connection and MUST be closed. We should use QueryIterator in a try with resource block.

    • findStream

      Stream<T> findStream()
      Execute the query returning a Stream.

      Note that the Stream holds resources related to the underlying resultSet and potentially connection and MUST be closed. We should use the Stream in a try with resource block.

    • findEach

      void findEach(Consumer<T> consumer)
      Execute the query iterating a row at a time.

      This streaming type query is useful for large query execution as only 1 row needs to be held in memory.

    • findEach

      void findEach(int batch, Consumer<List<T>> consumer)
      Execute the query iterating the results and batching them for the consumer.

      This runs like findEach streaming results from the database but just collects the results into batches to pass to the consumer.

      Parameters:
      batch - The number of dto beans to collect before given them to the consumer
      consumer - The consumer to process the batch of DTO beans

    • findEachWhile

      void findEachWhile(Predicate<T> consumer)
      Execute the query iterating a row at a time with the ability to stop consuming part way through.

      Returning false after processing a row stops the iteration through the query results.

      This streaming type query is useful for large query execution as only 1 row needs to be held in memory.

    • findOne

      @Nullable T findOne()
      Execute the query returning a single bean.

    • findOneOrEmpty

      Optional<T> findOneOrEmpty()
      Execute the query returning an optional bean.

    • setParameters

      DtoQuery<T> setParameters(Object... value)
      Bind all the parameters using index positions.

      Binds each parameter moving the index position each time.

      A convenience for multiple calls to setParameter(Object)

    • setParameter

      DtoQuery<T> setParameter(Object value)
      Bind the next parameter using index position.

      Bind the parameter using index position starting at 1 and incrementing.

    • setParameter

      DtoQuery<T> setParameter(String name, Object value)
      Bind the named parameter.

    • setArrayParameter

      DtoQuery<T> setArrayParameter(String name, Collection<?> values)
      Bind the named multi-value array parameter which we would use with Postgres ANY.

      For Postgres this binds an ARRAY rather than expands into multiple bind values.

    • setParameter

      DtoQuery<T> setParameter(int position, Object value)
      Bind the parameter by its index position (1 based like JDBC).

    • setFirstRow

      DtoQuery<T> setFirstRow(int firstRow)
      Set the index of the first row of the results to return.

    • setMaxRows

      DtoQuery<T> setMaxRows(int maxRows)
      Set the maximum number of query results to return.

    • setRelaxedMode

      DtoQuery<T> setRelaxedMode()
      When resultSet columns are not able to be mapped to a bean property then instead of throwing effectively skip reading that column.

    • setLabel

      DtoQuery<T> setLabel(String label)
      Set a label on the query to make it easier to identify queries related to query execution statistics.
      Parameters:
      label - A label that is unique to the DTO bean type.

    • setProfileLocation

      DtoQuery<T> setProfileLocation(ProfileLocation profileLocation)
      Set the profile location of this query. This is used to relate query execution metrics back to a location like a specific line of code.

    • setTimeout

      DtoQuery<T> setTimeout(int secs)
      Set a timeout on this query.

      This will typically result in a call to setQueryTimeout() on a preparedStatement. If the timeout occurs an exception will be thrown - this will be a SQLException wrapped up in a PersistenceException.

      Parameters:
      secs - the query timeout limit in seconds. Zero means there is no limit.

    • setBufferFetchSizeHint

      DtoQuery<T> setBufferFetchSizeHint(int bufferFetchSizeHint)
      A hint which for JDBC translates to the Statement.fetchSize().

      Gives the JDBC driver a hint as to the number of rows that should be fetched from the database when more rows are needed for ResultSet.

    • usingTransaction

      DtoQuery<T> usingTransaction(Transaction transaction)
      Use the explicit transaction to execute the query.