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

Performing CRUD operations

We can modify the content of a data store.

For more details on create, retrieve, update, and delete (CRUD) operations, see CDTDatastore CRUD documentation.

For create, retrieve, update, and delete (CRUD) operations on a remote store, see the Cloudant® Document API

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

Create data

Procedure

Save data.

BEFORE (with IMFData/CloudantToolkit):

// Use an existing store
CDTStore *store = existingStore;

// Create your Automobile to save
Automobile *automobile = [[Automobile alloc] initWithMake:@"Toyota" model:@"Corolla" year: 2006];

[store save:automobile completionHandler:^(id savedObject, NSError *error) {
    if (error) {
        // save was not successful, handler received an error
    } else {
        // use the result
        Automobile *savedAutomobile = savedObject;
        NSLog(@"saved revision: %@", savedAutomobile);
    }
}];

 // Use an existing store
let store:CDTStore = existingStore

// Create your object to save
let automobile = Automobile(make: "Toyota", model: "Corolla", year: 2006)

store.save(automobile, completionHandler: { (savedObject:AnyObject!, error:NSError!) -> Void in
    if nil != error {
        //Save was not successful, handler received an error
    } else {
        // Use the result
        print("Saved revision: \(savedObject)")
    }
})

// Use an existing store
Store store = existingStore;

// Create your object to save
Automobile automobile = new Automobile("Toyota", "Corolla", 2006);

// Save automobile to store
Task<Object> saveTask = store.save(automobile); 
saveTask.continueWith(new Continuation<Object, Void>() {
    @Override
    public Void then(Task<Object> task) throws Exception {
        if (task.isFaulted()) {
            // save was not successful, task.getError() contains the error
        } else {
            // use the result
            Automobile savedAutomobile = (Automobile) task.getResult();
        }
        return null;
    }
});

AFTER (with Cloudant Sync):

// Use an existing store
CDTDatastore *datastore = existingDatastore;

// Create document body
CDTMutableDocumentRevision * revision = [CDTMutableDocumentRevision revision];
revision.body = @{@"@datatype" : @"Automobile", @"make" :@"Toyota", @"model": @"Corolla", @"year" : @2006};

NSError *error = nil;
CDTDocumentRevision *createdRevision = [datastore createDocumentFromRevision:revision error:&error];

if (error) {
    // save was not successful, handler received an error
} else {
    // use the result
    NSLog(@"Revision: %@", createdRevision);
}

// Use an existing store
let datastore:CDTDatastore = existingDatastore

// Create document body
let revision = CDTMutableDocumentRevision()
revision.setBody(["make":"Toyota","model":"Corolla","year":2006])

var createdRevision:CDTDocumentRevision?
do{
    createdRevision = try datastore.createDocumentFromRevision(revision)
    NSLog("Revision: \(createdRevision)");
}catch let error as NSError{
    // Handle error
}

// Use an existing store
Datastore datastore = existingStore;

// Create document body
Map<String, Object> body = new HashMap<String, Object>();
body.put("@datatype", "Automobile");
body.put("make", "Toyota");
body.put("model", "Corolla");
body.put("year", 2006);

// Create revision and set body
MutableDocumentRevision revision  = new MutableDocumentRevision();
revision.body = DocumentBodyFactory.create(body);

// Save revision to store
DocumentRevision savedRevision = datastore.createDocumentFromRevision(revision);

Reading data

We can fetch data.

Procedure

Read data.

BEFORE (with IMFData/CloudantToolkit):

CDTStore *store = existingStore;
NSString *automobileId = existingAutomobileId;

// Fetch Autombile from Store
[store fetchById:automobileId completionHandler:^(id object, NSError *error) {
    if (error) {
        // fetch was not successful, handler received an error
    } else {
        // use the result
        Automobile *savedAutomobile = object;
        NSLog(@"fetched automobile: %@", savedAutomobile);
    }
}];

// Using an existing store and Automobile
let store:CDTStore = existingStore
let automobileId:String = existingAutomobileId

// Fetch Autombile from Store
store.fetchById(automobileId, completionHandler: { (object:AnyObject!, error:NSError!) -> Void in
    if nil != error {
        // Fetch was not successful, handler received an error
    } else {
        // Use the result
        let savedAutomobile:Automobile = object as! Automobile
        print("Fetched automobile: \(savedAutomobile)")
    }
})

// Use an existing store and documentId
Store store = existingStore;
String automobileId = existingAutomobileId;

// Fetch the automobile from the store
Task<Object> fetchTask = store.fetchById(automobileId);
fetchTask.continueWith(new Continuation<Object, Void>() {
    @Override
    public Void then(Task<Object> task) throws Exception {
        if (task.isFaulted()) {
            // fetch was not successful, task.getError() contains the error
        } else {
            // use the result 
            Automobile fetchedAutomobile = (Automobile) task.getResult();
        }
        return null;
    }
});

AFTER (with Cloudant Sync):

// Use an existing store and documentId
CDTDatastore *datastore = existingDatastore;
NSString *documentId = existingDocumentId;

// Fetch the CDTDocumentRevision from the store
NSError *error = nil;
CDTDocumentRevision *fetchedRevision = [datastore getDocumentWithId:documentId error:&error];

if (error) {
    // fetch was not successful, handler received an error
} else {
    // use the result
    NSLog(@"Revision: %@", fetchedRevision);
}

// Use an existing store and documentId
let datastore:CDTDatastore = existingDatastore
let documentId:String = existingDocumentId

var fetchedRevision:CDTDocumentRevision?
do{
    fetchedRevision = try datastore.getDocumentWithId(documentId)
    NSLog("Revision: \(fetchedRevision)");
}catch let error as NSError{
    // Handle error
}

// Use an existing store and documentId
Datastore datastore = existingStore;
String documentId = existingDocumentId;

// Fetch the revision from the store
DocumentRevision fetchedRevision = datastore.getDocument(documentId);

Update data

To update an object, run a save on an existing object. Because the item exists, it is updated.

Procedure

Update objects.

BEFORE (with IMFData/CloudantToolkit):

// Use an existing store and Automobile
CDTStore *store = existingStore;
Automobile *automobile = existingAutomobile;

// Update some of the values in the Automobile
automobile.year = 2015;

// Save Autombile to the store
[store save:automobile completionHandler:^(id savedObject, NSError *error) {
    if (error) {
        // sasve was not successful, handler received an error
    } else {
        // use the result
        Automobile *savedAutomobile = savedObject;
        NSLog(@"saved automobile: %@", savedAutomobile);
    }
}];

// Use an existing store and Automobile
let store:CDTStore = existingStore
let automobile:Automobile = existingAutomobile

// Update some of the values in the Automobile
automobile.year = 2015

// Save Autombile to the store
store.save(automobile, completionHandler: { (savedObject:AnyObject!, error:NSError!) -> Void in
    if nil != error {
        // Update was not successful, handler received an error
    } else {
        // Use the result
        let savedAutomobile:Automobile = savedObject as! Automobile
        print("Updated automobile: \(savedAutomobile)")
    }
})

// Use an existing store and Automobile
Store store = existingStore;
Automobile automobile = existingAutomobile;

// Update some of the values in the Automobile
automobile.setYear(2015);

// Save automobile to store
Task<Object> saveTask = store.save(automobile);
saveTask.continueWith(new Continuation<Object, Void>() {
    @Override
    public Void then(Task<Object> task) throws Exception {
        if (task.isFaulted()) {
            // save was not successful, task.getError() contains the error
        } else {
            // use the result
            Automobile savedAutomobile = (Automobile) task.getResult();
        }
        return null;
    }
});

AFTER (with Cloudant Sync):

// Use an existing store and document
CDTDatastore *datastore = existingDatastore;
CDTMutableDocumentRevision *documentRevision = [existingDocumentRevision mutableCopy];

// Update some of the values in the revision
[documentRevision.body setValue:@2015 forKey:@"year"];

NSError *error = nil;
CDTDocumentRevision *updatedRevision = [datastore updateDocumentFromRevision:documentRevision error:&error];
if (error) {
    // save was not successful, handler received an error
} else {
    // use the result
    NSLog(@"Revision: %@", updatedRevision);
}

// Use an existing store and document
let datastore:CDTDatastore = existingDatastore
let documentRevision:CDTMutableDocumentRevision = existingDocumentRevision.mutableCopy()

// Update some of the values in the revision
documentRevision.body()["year"] = 2015

var updatedRevision:CDTDocumentRevision?
do{
    updatedRevision = try datastore.updateDocumentFromRevision(documentRevision)
    NSLog("Revision: \(updatedRevision)");
}catch let error as NSError{
    // Handle error
}

// Use an existing store and documentId
// Use an existing store
Datastore datastore = existingStore;

// Make a MutableDocumentRevision from the existing revision
MutableDocumentRevision revision = existingRevision.mutableCopy();

// Update some of the values in the revision
Map<String, Object> body = revision.getBody().asMap();
body.put("year", 2015);
revision.body = DocumentBodyFactory.create(body);

// Save revision to store
DocumentRevision savedRevision = datastore.updateDocumentFromRevision(revision);

Deleting data

To delete an object, pass the object that we want to delete to the store.

Procedure

Delete objects.

BEFORE (with IMFData/CloudantToolkit):

// Using an existing store and Automobile
CDTStore *store = existingStore;
Automobile *automobile = existingAutomobile;

// Delete the Automobile object from the store
[store delete:automobile completionHandler:^(NSString *deletedObjectId, NSString *deletedRevisionId, NSError *error) {
    if (error) {
        // delete was not successful, handler received an error
    } else {
        // use the result
        NSLog(@"deleted Automobile doc-%@-rev-%@", deletedObjectId, deletedRevisionId);
    }
}];

// Using an existing store and Automobile
let store:CDTStore = existingStore
let automobile:Automobile = existingAutomobile

// Delete the Automobile object
store.delete(automobile, completionHandler: { (deletedObjectId:String!, deletedRevisionId:String!, error:NSError!) -> Void in
    if nil != error {
        // delete was not successful, handler received an error
    } else {
        // use the result
        print("deleted document doc-\(deletedObjectId)-rev-\(deletedRevisionId)")
    }
})

// Use an existing store and automobile
Store store = existingStore;
Automobile automobile = existingAutomobile;

// Delete the automobile from the store
Task<String> deleteTask = store.delete(automobile);
deleteTask.continueWith(new Continuation<String, Void>() {
    @Override
    public Void then(Task<String> task) throws Exception {
        if (task.isFaulted()) {
            // delete was not successful, task.getError() contains the error
        } else {
            // use the result
            String deletedAutomobileId = task.getResult();
        }
        return null;
    }
});

AFTER (with Cloudant Sync):

// Use an existing store and revision
CDTDatastore *datastore = existingDatastore;
CDTDocumentRevision *documentRevision = existingDocumentRevision;

// Delete the CDTDocumentRevision from the store
NSError *error = nil;
CDTDocumentRevision *deletedRevision = [datastore deleteDocumentFromRevision:documentRevision error:&error];
if (error) {
    // delete was not successful, handler received an error
} else {
    // use the result
    NSLog(@"deleted document: %@", deletedRevision);
}

// Use an existing store and revision
let datastore:CDTDatastore = existingDatastore
let documentRevision:CDTDocumentRevision = existingDocumentRevision

var deletedRevision:CDTDocumentRevision?
do{
    deletedRevision = try datastore.deleteDocumentFromRevision(documentRevision)
    NSLog("Revision: \(deletedRevision)");
}catch let error as NSError{
    // Handle error
}

// Use an existing store and revision
Datastore datastore = existingStore;
BasicDocumentRevision documentRevision = (BasicDocumentRevision) existingDocumentRevision;

// Delete revision from store
DocumentRevision deletedRevision = datastore.deleteDocumentFromRevision(documentRevision);