Examples of PreparedQuery

com.cfinkel.reports.wrappers.PreparedQuery
$Author: charles $ $Revision: 8904 $ $Date: 2006-05-01 18:02:06 -0400 (Mon, 01 May 2006) $
Created by IntelliJ IDEA. User: charles Date: Mar 25, 2006 Time: 6:09:54 PM To change this template use File | Settings | File Templates.
com.google.appengine.api.datastore.PreparedQuery
org.apache.openjpa.kernel.PreparedQuery
A prepared query associates a compiled query to a parsed state that can be executed possibly with more efficiency. An obvious example is to associate a compiled query to an executable SQL string. The query expressed in target language can be executed directly bypassing the critical translation cost to the data store target language on every execution. As the subsequent execution of a cached query will bypass normal query compilation, the post-compilation state of the original query is captured by this receiver to be transferred to the executable query instance. This receiver must not hold any context-sensitive reference or dependency. Because the whole idea of preparing a query (for a cost) is to be able to execute the same logical query in different persistence contexts. However, a prepared query may not be valid when some parameters of execution context such as lock group or fetch plan changes in a way that will change the target query. Refer to {@link PreparedQueryCache} for invalidation mechanism onpossible actions under such circumstances. The query execution model does account for context changes that do not impact the target query e.g. bind variables. @author Pinaki Poddar @since 2.0.0

Examples of com.google.appengine.api.datastore.PreparedQuery

      if(!gaeCtx.isActive()){
        // cursor not yet created
        switch(fetchType.fetchType){
        case KEYS_ONLY:
          {
            PreparedQuery pq = prepareKeysOnly(query);
            if(!gaeCtx.useCursor){
              // then uses offset (in case of IN or != operators)
              //if(offset.isActive()){
              //  fetchOptions.offset(gaeCtx.realOffset);
              //}            
              fetchOptions.offset(gaeCtx.realOffset);
            }
            
            // we can't use real asynchronous function with cursors
            // so the page is extracted at once and wrapped into a SienaFuture
            QueryResultList<Entity> entities = pq.asQueryResultList(fetchOptions);


            // activates the GaeCtx now that it is initialised
            gaeCtx.activate();
            // sets the current cursor (in stateful mode, cursor is always kept for further use)
            if(pag.isPaginating()){
              Cursor cursor = entities.getCursor();
              if(cursor!=null){
                gaeCtx.addCursor(cursor.toWebSafeString());
              }
              
              // if paginating and 0 results then no more data else resets noMoreDataAfter
              if(entities.size()==0){
                gaeCtx.noMoreDataAfter = true;
              } else {
                gaeCtx.noMoreDataAfter = false;
              }
            }else{
              Cursor cursor = entities.getCursor();
              if(cursor!=null){
                gaeCtx.addAndMoveCursor(entities.getCursor().toWebSafeString());
              }
              // keeps track of the offset anyway if not paginating
              gaeCtx.realOffset+=entities.size();
            }                      
            
            return mapKeysOnly(query, entities);
          }
        case NORMAL:
        default:
          {
            PreparedQuery pq = prepare(query);
            if(!gaeCtx.useCursor){
              // then uses offset (in case of IN or != operators)
              //if(offset.isActive()){
              //  fetchOptions.offset(gaeCtx.realOffset);
              //}
              fetchOptions.offset(gaeCtx.realOffset);
            }
            // we can't use real asynchronous function with cursors
            // so the page is extracted at once and wrapped into a SienaFuture
            QueryResultList<Entity> entities = pq.asQueryResultList(fetchOptions);
            
            // activates the GaeCtx now that it is initialised
            gaeCtx.activate();
            // sets the current cursor (in stateful mode, cursor is always kept for further use)
            if(pag.isPaginating()){
              Cursor cursor = entities.getCursor();
              if(cursor!=null){
                gaeCtx.addCursor(cursor.toWebSafeString());
              }
              // if paginating and 0 results then no more data else resets noMoreDataAfter
              if(entities.size()==0){
                gaeCtx.noMoreDataAfter = true;
              } else {
                gaeCtx.noMoreDataAfter = false;
              }
            }else{
              Cursor cursor = entities.getCursor();
              if(cursor!=null){
                gaeCtx.addAndMoveCursor(entities.getCursor().toWebSafeString());
              }
              // keeps track of the offset anyway if not paginating
              gaeCtx.realOffset+=entities.size();
            }
            
            return map(query, entities);
          }
        }
        
      }else {
        switch(fetchType.fetchType){
        case KEYS_ONLY:
          {
            // we prepare the query each time
            PreparedQuery pq = prepareKeysOnly(query);
            QueryResultList<Entity> entities;
            if(!gaeCtx.useCursor){
              // then uses offset (in case of IN or != operators)
              //if(offset.isActive()){
              //  fetchOptions.offset(gaeCtx.realOffset);
              //}
              fetchOptions.offset(gaeCtx.realOffset);
              // we can't use real asynchronous function with cursors
              // so the page is extracted at once and wrapped into a SienaFuture
              entities = pq.asQueryResultList(fetchOptions);
            }else {
              // we can't use real asynchronous function with cursors
              // so the page is extracted at once and wrapped into a SienaFuture
              String cursor = gaeCtx.currentCursor();
              if(cursor!=null){
                entities = pq.asQueryResultList(
                  fetchOptions.startCursor(Cursor.fromWebSafeString(cursor)));
              }
              else {
                entities = pq.asQueryResultList(fetchOptions);
              }
            }
            
            // sets the current cursor (in stateful mode, cursor is always kept for further use)
            if(pag.isPaginating()){
              Cursor cursor = entities.getCursor();
              if(cursor!=null){
                gaeCtx.addCursor(cursor.toWebSafeString());
              }
              // if paginating and 0 results then no more data else resets noMoreDataAfter
              if(entities.size()==0){
                gaeCtx.noMoreDataAfter = true;
              } else {
                gaeCtx.noMoreDataAfter = false;
              }
            }else{
              Cursor cursor = entities.getCursor();
              if(cursor!=null){
                gaeCtx.addAndMoveCursor(entities.getCursor().toWebSafeString());
              }
              // keeps track of the offset anyway if not paginating
              gaeCtx.realOffset+=entities.size();
            }
            //}
            
            return mapKeysOnly(query, entities);
          }
        case NORMAL:
        default:
          {
            PreparedQuery pq = prepare(query);
            QueryResultList<Entity> entities;
            if(!gaeCtx.useCursor){
              // then uses offset (in case of IN or != operators)
              //if(offset.isActive()){
              //  fetchOptions.offset(gaeCtx.realOffset);
              //}
              
              fetchOptions.offset(gaeCtx.realOffset);
              // we can't use real asynchronous function with cursors
              // so the page is extracted at once and wrapped into a SienaFuture
              entities = pq.asQueryResultList(fetchOptions);
            }else {
              // we can't use real asynchronous function with cursors
              // so the page is extracted at once and wrapped into a SienaFuture
              String cursor = gaeCtx.currentCursor();
              if(cursor!=null){
                entities = pq.asQueryResultList(
                  fetchOptions.startCursor(Cursor.fromWebSafeString(gaeCtx.currentCursor())));
              }else {
                entities = pq.asQueryResultList(fetchOptions);
              }
            }
            
            // sets the current cursor (in stateful mode, cursor is always kept for further use)
            if(pag.isPaginating()){

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Examples of com.google.appengine.api.datastore.PreparedQuery

        // cursor not yet created
        switch(fetchType.fetchType){
        case ITER:
        default:
          {
            PreparedQuery pq = prepare(query);
            
            if(pag.isPaginating()){
              // in case of pagination, we need to allow asynchronous calls such as:
              // QueryAsync<MyClass> query = pm.createQuery(MyClass).paginate(5).stateful().order("name");
              // SienaFuture<Iterable<MyClass>> future1 = query.iter();
              // SienaFuture<Iterable<MyClass>> future2 = query.nextPage().iter();
              // Iterable<MyClass> it = future1.get().iterator();
              // while(it.hasNext()) { // do it }
              // it = future2.get().iterator();
              // while(it.hasNext()) { // do it }
              
              // so we can't use the asQueryResultIterable as the cursor is not moved to the end of the current page
              // but moved at each call of iterable.iterator().next()
              // thus we use the List in this case to be able to move directly to the next page with cursors
              QueryResultList<Entity> entities = pq.asQueryResultList(fetchOptions);


              // activates the GaeCtx now that it is initialised
              gaeCtx.activate();
              // sets the current cursor (in stateful mode, cursor is always kept for further use)
              //if(gaeCtx.useCursor){
              Cursor cursor = entities.getCursor();
              if(cursor!=null){
                gaeCtx.addCursor(cursor.toWebSafeString());
              }
              //}
              return new GaeSienaIterable<T>(this, entities, query);
            }else {
              // if not paginating, we simply use the queryresultiterable and moves the current cursor
              // while iterating
              QueryResultIterable<Entity> entities = pq.asQueryResultIterable(fetchOptions);
              // activates the GaeCtx now that it is initialised
              gaeCtx.activate();
              return new GaeSienaIterableWithCursor<T>(this, entities, query);
            }
            
          }
        }
        
      }else {
        switch(fetchType.fetchType){
        case ITER:
        default:
          {
            PreparedQuery pq = prepare(query);
            if(pag.isPaginating()){
              // in case of pagination, we need to allow asynchronous calls such as:
              // QueryAsync<MyClass> query = pm.createQuery(MyClass).paginate(5).stateful().order("name");
              // SienaFuture<Iterable<MyClass>> future1 = query.iter();
              // SienaFuture<Iterable<MyClass>> future2 = query.nextPage().iter();
              // Iterable<MyClass> it = future1.get().iterator();
              // while(it.hasNext()) { // do it }
              // it = future2.get().iterator();
              // while(it.hasNext()) { // do it }
              
              // so we can't use the asQueryResultIterable as the cursor is not moved to the end of the current page
              // but moved at each call of iterable.iterator().next()
              // thus we use the List in this case to be able to move directly to the next page with cursors
              QueryResultList<Entity> entities;
              if(!gaeCtx.useCursor){
                // then uses offset (in case of IN or != operators)
                //if(offset.isActive()){
                //  fetchOptions.offset(gaeCtx.realOffset);
                //}
                fetchOptions.offset(gaeCtx.realOffset);
                entities = pq.asQueryResultList(fetchOptions);
              }else {
                String cursor = gaeCtx.currentCursor();
                if(cursor!=null){
                  entities = pq.asQueryResultList(
                    fetchOptions.startCursor(Cursor.fromWebSafeString(cursor)));
                }else {
                  entities = pq.asQueryResultList(fetchOptions);
                }
                
                // sets the current cursor (in stateful mode, cursor is always kept for further use)
                //if(gaeCtx.useCursor){
                gaeCtx.addCursor(entities.getCursor().toWebSafeString());
                //}
              }
              return new GaeSienaIterable<T>(this, entities, query);
            }else {
              // if not paginating, we simply use the queryresultiterable and moves the current cursor
              // while iterating
              QueryResultIterable<Entity> entities;
              if(!gaeCtx.useCursor){
                // then uses offset (in case of IN or != operators)
                //if(offset.isActive()){
                //  fetchOptions.offset(gaeCtx.realOffset);
                //}
                fetchOptions.offset(gaeCtx.realOffset);
                entities = pq.asQueryResultIterable(fetchOptions);
              }else {
                String cursor = gaeCtx.currentCursor();
                if(cursor!=null){
                  entities = pq.asQueryResultIterable(
                    fetchOptions.startCursor(Cursor.fromWebSafeString(gaeCtx.currentCursor())));
                }else {
                  entities = pq.asQueryResultIterable(fetchOptions);  
                }
              }
              return new GaeSienaIterableWithCursor<T>(this, entities, query);
            }
          }

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Examples of com.google.appengine.api.datastore.PreparedQuery

   * @param dio
   *            DepartmentInformationObject - department to be checked
   * @return boolean value whether the department exists or not
   */
  public boolean checkDepartmentExists(DepartmentInformationObject dio) {
    PreparedQuery pq = queryDepartment(dio);
    if (pq.countEntities(FetchOptions.Builder.withDefaults()) == 0)
      return false;
    return true;


  }

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Examples of com.google.appengine.api.datastore.PreparedQuery

   * @param cio
   *            CourseInformationObject - course to be checked
   * @return boolean value whether the course exists or not
   */
  public boolean checkCourseExists(CourseInformationObject cio) {
    PreparedQuery pq = queryCourse(cio);
    if (pq.countEntities(FetchOptions.Builder.withDefaults()) == 0)
      return false;
    return true;


  }

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Examples of com.google.appengine.api.datastore.PreparedQuery

   * @param sio
   *            SectionInformationObject - section to be checked
   * @return
   */
  public boolean checkSectionExists(SectionInformationObject sio) {
    PreparedQuery pq = querySection(sio);
    if (pq.countEntities(FetchOptions.Builder.withDefaults()) == 0)
      return false;
    return true;
  }

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Examples of com.google.appengine.api.datastore.PreparedQuery

    }
    return false;
  }


  public boolean checkBookExists(BookInformationObject bio) {
    PreparedQuery pq = queryBook(bio);
    if (pq.countEntities(FetchOptions.Builder.withDefaults()) == 0)
      return false;
    return true;
  }

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Examples of com.google.appengine.api.datastore.PreparedQuery

  private Key makeParentKey(CourseInformationObject cio) {
    Query q = new Query(DEPARTMENT_KIND);
    q.setKeysOnly();
    q.addFilter(DEPARTMENT_ID_PROPERTY, FilterOperator.EQUAL,
        cio.getDepartmentId());
    PreparedQuery pq = datastore.prepare(q);
    return pq.asSingleEntity().getKey();
  }

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Examples of com.google.appengine.api.datastore.PreparedQuery

    Query q = new Query(COURSE_KIND);
    q.setKeysOnly();
    q.addFilter(DEPARTMENT_ID_PROPERTY, FilterOperator.EQUAL,
        sio.getDepartmentId());
    q.addFilter(COURSE_ID_PROPERTY, FilterOperator.EQUAL, sio.getCourseId());
    PreparedQuery pq = datastore.prepare(q);
    return pq.asSingleEntity().getKey();
  }

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Examples of com.google.appengine.api.datastore.PreparedQuery

    q.addFilter(DEPARTMENT_ID_PROPERTY, FilterOperator.EQUAL,
        bio.getDepartmentId());
    q.addFilter(COURSE_ID_PROPERTY, FilterOperator.EQUAL, bio.getCourseId());
    q.addFilter(SECTION_ID_PROPERTY, FilterOperator.EQUAL,
        bio.getSectionId());
    PreparedQuery pq = datastore.prepare(q);
    return pq.asSingleEntity().getKey();
  }

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Examples of com.google.appengine.api.datastore.PreparedQuery

  }


  public DepartmentInformationObject queryDepartmentFromId(String departmentId) {
    Query q = new Query(DEPARTMENT_KIND);
    q.addFilter(DEPARTMENT_ID_PROPERTY, FilterOperator.EQUAL, departmentId);
    PreparedQuery pq = datastore.prepare(q);
    Entity e = pq.asSingleEntity();
    if (e == null)
      return null;
    return getDepartmentFromEntity(e);
  }

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