For up-to-date product documentation, see the IBM MobileFirst Foundation Developer Center.

Create indexes

To perform queries, we must create an index.

For more details, see CDTDatastore Query documentation. For query operations on a remote store, see the Cloudant® Query API.

For more details, see Cloudant Sync Query documentation. For CRUD operations on a remote store, see Cloudant's Query API.

Procedure

• Create an index that includes the data type. Indexing with the data type is useful when an object mapper is set on the data store.

  BEFORE (with IMFData/CloudantToolkit):

   // Use an existing data store
  CDTStore *store = existingStore;
  
  // The data type to use for the Automobile class
  NSString *dataType = [store.mapper dataTypeForClassName:NSStringFromClass([Automobile class])];
  
  // Create the index
  [store createIndexWithDataType:dataType fields:@[@"year", @"make"] completionHandler:^(NSError *error) {
      if(error){
          // Handle error
      }else{
          // Continue application flow
      }
  }];

  // A store that has been previously created.
  let store:CDTStore = existingStore
  
  // The data type to use for the Automobile class
  let dataType:String = store.mapper.dataTypeForClassName(NSStringFromClass(Automobile.classForCoder()))
  
  // Create the index
  store.createIndexWithDataType(dataType, fields: ["year","make"]) { (error:NSError!) -> Void in
      if nil != error {
          // Handle error
      } else {
          // Continue application flow
      }
  }

  

  // Use an existing data store
  Store store = existingStore;
  
  // The data type to use for the Automobile class
  String dataType = store.getMapper().getDataTypeForClassName(Automobile.class.getCanonicalName());
  
  // The fields to index.
  List<IndexField> indexFields = new ArrayList<IndexField>();
  indexFields.add(new IndexField("year"));
  indexFields.add(new IndexField("make"));
  
  // Create the index
  Task<Void> indexTask = store.createIndexWithDataType(dataType, indexFields);
  indexTask.continueWith(new Continuation<Void, Void>() {
      @Override
      public Void then(Task<Void> task) throws Exception {
          if(task.isFaulted()){
              // Handle error
          }else{
              // Continue application flow
          }
          return null;
      }
  });

  AFTER (with Cloudant Sync):

  // A store that has been previously created.
  CDTDatastore *datastore = existingDatastore;
  
  NSString *indexName = [datastore ensureIndexed:@[@"@datatype", @"year", @"make"] withName:@"automobileindex"];
  if(!indexName){
      // Handle error
  }

  // A store that has been previously created.
  let datastore:CDTDatastore = existingDatastore
  
  // Create the index
  let indexName:String? = datastore.ensureIndexed(["@datatype","year","make"], withName: "automobileindex")
  if(indexName == nil){
      // Handle error
  }

  

  // Use an existing store
  Datastore datastore = existingStore;
  
  // Create an IndexManager
  IndexManager indexManager = new IndexManager(datastore);
  
  // The fields to index.
  List<Object> indexFields = new ArrayList<Object>();
  indexFields.add("@datatype");
  indexFields.add("year");
  indexFields.add("make");
  
  // Create the index
  indexManager.ensureIndexed(indexFields, "automobile_index");

• Delete indexes.

  BEFORE (with IMFData/CloudantToolkit):

  // Use an existing data store
  CDTStore *store = existingStore;
  NSString *indexName = existingIndexName;
  
  // Delete the index
  [store deleteIndexWithName:indexName completionHandler:^(NSError *error) {
      if(error){
          // Handle error
      }else{
          // Continue application flow
      }
  }];

  // Use an existing store
  let store:CDTStore = existingStore
  
  // The data type to use for the Automobile class
  let dataType:String = store.mapper.dataTypeForClassName(NSStringFromClass(Automobile.classForCoder()))
  
  // Delete the index
  store.deleteIndexWithDataType(dataType, completionHandler: { (error:NSError!) -> Void in
      if nil != error {
          // Handle error
      } else {
          // Continue application flow
      }
  })

  

  // Use an existing data store
  Store store = existingStore;
  String indexName = existingIndexName;
  
  // Delete the index
  Task<Void> indexTask = store.deleteIndex(indexName);
  indexTask.continueWith(new Continuation<Void, Void>() {
      @Override
      public Void then(Task<Void> task) throws Exception {
          if(task.isFaulted()){
              // Handle error
          }else{
              // Continue application flow
          }
          return null;
      }
  });

  AFTER (with Cloudant Sync):

  // Use an existing store
  CDTDatastore *datastore = existingDatastore;
  NSString *indexName = existingIndexName;
  
  // Delete the index
  BOOL success = [datastore deleteIndexNamed:indexName];
  if(!success){
      // Handle error
  }

  // A store that has been previously created.
  let datastore:CDTDatastore = existingDatastore
  let indexName:String = existingIndexName
  
  // Delete the index
  let success:Bool = datastore.deleteIndexNamed(indexName)
  if(!success){
      // Handle error
  }

  

  // Use an existing store
  Datastore datastore = existingStore;
  String indexName = existingIndexName;
  IndexManager indexManager = existingIndexManager;
  
  // Delete the index
  indexManager.deleteIndexNamed(indexName);

Parent topic: Migrating apps storing mobile data in Cloudant with IMFData or Cloudant SDK