Geodatabase transactions

View inMAUIUWPWPFWinUIView on GitHub

Use transactions to manage how changes are committed to a geodatabase.

Image of geodatabase transactions

Use case

Transactions allow you to control how changes are added to a database. This is useful to ensure that when multiple changes are made to a database, they all succeed or fail at once. For example, you could have a business rule that both parent/guardian and student must be added to a database used for calculating school bus routes. You can use transactions to avoid breaking the business rule if you lose power while between the steps of adding the student and parent/guardian.

How to use the sample

When the sample loads, a feature service is taken offline as a geodatabase. When the geodatabase is ready, you can add multiple types of features. To apply edits directly, uncheck the 'Require a transaction for edits' checkbox. When using transactions, use the buttons to start editing and stop editing. When you stop editing, you can choose to commit the changes or roll them back. At any point, you can synchronize the local geodatabase with the feature service.

How it works

  1. Take the feature service offline as a geodatabase and display the local tables from the geodatabase in feature layers.
  2. If the checkbox is checked, begin the transaction on the geodatabase.
  3. Add one or more features.
  4. When ready, either commit the transaction to the geodatabase or roll back the transaction.
  5. Use a geodatabase sync task to sync changes to the local geodatabase with the feature service.

Relevant API

  • Geodatabase
  • Geodatabase.BeginTransaction
  • Geodatabase.CommitTransaction
  • Geodatabase.IsInTransaction
  • Geodatabase.RollbackTransaction
  • GeometryEditor

About the data

The sample uses a publicly-editable, sync-enabled feature service demonstrating a schema for recording wildlife sightings.

Tags

commit, database, geodatabase, geometry editor, transact, transactions

Sample Code

GeodatabaseTransactions.xaml.csGeodatabaseTransactions.xaml.csGeodatabaseTransactions.xaml
Use dark colors for code blocksCopy
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
// Copyright 2017 Esri.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// Language governing permissions and limitations under the License.

using Esri.ArcGISRuntime.Data;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Tasks;
using Esri.ArcGISRuntime.Tasks.Offline;
using Esri.ArcGISRuntime.UI.Editing;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using System;
using System.IO;
using System.Threading.Tasks;
using Windows.UI.Popups;

namespace ArcGIS.WinUI.Samples.GeodatabaseTransactions
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Geodatabase transactions",
        category: "Data",
        description: "Use transactions to manage how changes are committed to a geodatabase.",
        instructions: "When the sample loads, a feature service is taken offline as a geodatabase. When the geodatabase is ready, you can add multiple types of features. To apply edits directly, uncheck the 'Require a transaction for edits' checkbox. When using transactions, use the buttons to start editing and stop editing. When you stop editing, you can choose to commit the changes or roll them back. At any point, you can synchronize the local geodatabase with the feature service.",
        tags: new[] { "commit", "database", "geodatabase", "geometry editor", "transact", "transactions" })]
    public partial class GeodatabaseTransactions
    {
        // URL for the editable feature service.
        private const string SyncServiceUrl = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Sync/SaveTheBaySync/FeatureServer/";

        // Work in a small extent south of Galveston, TX.
        private Envelope _extent = new Envelope(-95.3035, 29.0100, -95.1053, 29.1298, SpatialReferences.Wgs84);

        // Store the local geodatabase to edit.
        private Geodatabase _localGeodatabase;

        // Store references to the Birds and Marine points tables.
        private GeodatabaseFeatureTable _birdTable;
        private GeodatabaseFeatureTable _marineTable;

        // Store a reference to the table to be edited.
        private GeodatabaseFeatureTable _editTable;

        public GeodatabaseTransactions()
        {
            InitializeComponent();

            // When the map view loads, add a new map.
            MyMapView.Loaded += (s, e) =>
            {
                // Create a new map with the oceans basemap and add it to the map view.
                Map map = new Map(BasemapStyle.ArcGISOceans);
                MyMapView.Map = map;
            };

            // When the spatial reference changes (the map loads) add the local geodatabase tables as feature layers.
            MyMapView.SpatialReferenceChanged += async (s, e) =>
            {
                // Call a function (and await it) to get the local geodatabase (or generate it from the feature service).
                await GetLocalGeodatabase();

                // Once the local geodatabase is available, load the tables as layers to the map.
                await LoadLocalGeodatabaseTables();
            };
        }

        private async Task GetLocalGeodatabase()
        {
            // Get the path to the local geodatabase for this platform (temp directory, for example).
            string localGeodatabasePath = GetGdbPath();

            try
            {
                // See if the geodatabase file is already present.
                if (File.Exists(localGeodatabasePath))
                {
                    // If the geodatabase is already available, open it, hide the progress control, and update the message.
                    _localGeodatabase = await Geodatabase.OpenAsync(localGeodatabasePath);
                    LoadingProgressBar.Visibility = Visibility.Collapsed;
                    MessageTextBlock.Text = "Using local geodatabase from '" + _localGeodatabase.Path + "'";
                }
                else
                {
                    // Create a new GeodatabaseSyncTask with the uri of the feature server to pull from.
                    Uri uri = new Uri(SyncServiceUrl);
                    GeodatabaseSyncTask gdbTask = await GeodatabaseSyncTask.CreateAsync(uri);

                    // Create parameters for the task: layers and extent to include, out spatial reference, and sync model.
                    GenerateGeodatabaseParameters gdbParams = await gdbTask.CreateDefaultGenerateGeodatabaseParametersAsync(_extent);
                    gdbParams.OutSpatialReference = MyMapView.SpatialReference;
                    gdbParams.SyncModel = SyncModel.Layer;
                    gdbParams.LayerOptions.Clear();
                    gdbParams.LayerOptions.Add(new GenerateLayerOption(0));
                    gdbParams.LayerOptions.Add(new GenerateLayerOption(1));

                    // Create a geodatabase job that generates the geodatabase.
                    GenerateGeodatabaseJob generateGdbJob = gdbTask.GenerateGeodatabase(gdbParams, localGeodatabasePath);

                    // Handle the job changed event and check the status of the job; store the geodatabase when it's ready.
                    generateGdbJob.StatusChanged += (s, e) =>
                    {
                        // See if the job succeeded.
                        if (generateGdbJob.Status == JobStatus.Succeeded)
                        {
                            DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () =>
                            {
                                // Hide the progress control and update the message.
                                LoadingProgressBar.Visibility = Visibility.Collapsed;
                                MessageTextBlock.Text = "Created local geodatabase";
                            });
                        }
                        else if (generateGdbJob.Status == JobStatus.Failed)
                        {
                            DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () =>
                            {
                                // Hide the progress control and report the exception.
                                LoadingProgressBar.Visibility = Visibility.Collapsed;
                                MessageTextBlock.Text = "Unable to create local geodatabase: " + generateGdbJob.Error.Message;
                            });
                        }
                    };

                    // Start the generate geodatabase job.
                    _localGeodatabase = await generateGdbJob.GetResultAsync();
                }
            }
            catch (Exception ex)
            {
                // Show a message for the exception encountered.
                DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () =>
                {
                    _ = new MessageDialog2("Unable to create offline database: " + ex.Message).ShowAsync();
                });
            }
        }

        // Function that loads the two point tables from the local geodatabase and displays them as feature layers.
        private async Task LoadLocalGeodatabaseTables()
        {
            if (_localGeodatabase == null) { return; }

            // Read the geodatabase tables and add them as layers.
            foreach (GeodatabaseFeatureTable table in _localGeodatabase.GeodatabaseFeatureTables)
            {
                try
                {
                    // Load the table so the TableName can be read.
                    await table.LoadAsync();

                    // Store a reference to the Birds table.
                    if (table.TableName.ToLower().Contains("birds"))
                    {
                        _birdTable = table;
                    }

                    // Store a reference to the Marine table.
                    if (table.TableName.ToLower().Contains("marine"))
                    {
                        _marineTable = table;
                    }

                    // Create a new feature layer to show the table in the map.
                    FeatureLayer layer = new FeatureLayer(table);
                    DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () => MyMapView.Map?.OperationalLayers.Add(layer));
                }
                catch (Exception e)
                {
                    await new MessageDialog2(e.ToString(), "Error").ShowAsync();
                }
            }

            // Handle the transaction status changed event.
            _localGeodatabase.TransactionStatusChanged += GdbTransactionStatusChanged;

            // Zoom the map view to the extent of the generated local datasets.
            DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () =>
            {
                MyMapView.SetViewpoint(new Viewpoint(_marineTable.Extent));
                StartEditingButton.IsEnabled = true;
            });
        }

        private void GdbTransactionStatusChanged(object sender, TransactionStatusChangedEventArgs e)
        {
            // Update UI controls based on whether the geodatabase has a current transaction.
            DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () =>
            {
                // These buttons should be enabled when there IS a transaction.
                AddBirdButton.IsEnabled = e.IsInTransaction;
                AddMarineButton.IsEnabled = e.IsInTransaction;
                StopEditingButton.IsEnabled = e.IsInTransaction;

                // These buttons should be enabled when there is NOT a transaction.
                StartEditingButton.IsEnabled = !e.IsInTransaction;
                SyncEditsButton.IsEnabled = !e.IsInTransaction;
            });
        }

        private string GetGdbPath()
        {
            // Get the UWP-specific path for storing the geodatabase.
            string folder = Windows.Storage.ApplicationData.Current.LocalFolder.Path;
            return Path.Combine(folder, "savethebay.geodatabase");
        }

        private void BeginTransaction(object sender, RoutedEventArgs e)
        {
            // See if there is a transaction active for the geodatabase.
            if (!_localGeodatabase.IsInTransaction)
            {
                // If not, begin a transaction.
                _localGeodatabase.BeginTransaction();
                MessageTextBlock.Text = "Transaction started";
            }
        }

        private void AddNewFeature(object sender, RoutedEventArgs args)
        {
            // See if it was the "Birds" or "Marine" button that was clicked.
            Button addFeatureButton = (Button)sender;

            try
            {
                // Store the correct table to edit (for the button clicked).
                if (addFeatureButton == AddBirdButton)
                {
                    _editTable = _birdTable;
                }
                else
                {
                    _editTable = _marineTable;
                }

                // Inform the user which table is being edited.
                MessageTextBlock.Text = "Click the map to add a new feature to the geodatabase table '" + _editTable.TableName + "'";

                // Use the geometry editor to allow the user to draw a point on the map.
                MyMapView.GeometryEditor.Start(GeometryType.Point);

                MyMapView.GeometryEditor.PropertyChanged += GeometryEditor_PropertyChanged;
            }
            catch (Exception ex)
            {
                // Report other exception messages.
                MessageTextBlock.Text = ex.Message;
            }
        }

        private async void GeometryEditor_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
        {
            // Check if the user finished drawing a point on the map.
            if (e.PropertyName == nameof(GeometryEditor.Geometry))
            {
                // Disconnect event handler to prevent multiple calls.
                MyMapView.GeometryEditor.PropertyChanged -= GeometryEditor_PropertyChanged;

                // Get the active geometry.
                Geometry geometry = MyMapView.GeometryEditor.Geometry;

                // Create a new feature (row) in the selected table.
                Feature newFeature = _editTable.CreateFeature();

                // Create a random value for the 'type' attribute (integer between 1 and 7).
                Random random = new Random(DateTime.Now.Millisecond);
                int featureType = random.Next(1, 7);

                // Set the geometry with the point the user clicked and the 'type' with the random integer.
                newFeature.Geometry = geometry;
                newFeature.SetAttributeValue("type", featureType);

                // Add the new feature to the table.
                await _editTable.AddFeatureAsync(newFeature);

                // Set the newly created feature message.
                MessageTextBlock.Text = "New feature added to the '" + _editTable.TableName + "' table";

                // Stop the geometry editor, clearing the active geometry.
                MyMapView.GeometryEditor.Stop();
            }
        }

        private async void StopEditTransaction(object sender, RoutedEventArgs e)
        {
            // Create a new dialog that prompts for commit, rollback, or cancel
            var promptDialog = new MessageDialog2("Commit your edits to the local geodatabase or rollback to discard them.", "Stop Editing");
            UICommand commitCommand = new UICommand("Commit");
            UICommand rollbackCommand = new UICommand("Rollback");
            UICommand cancelCommand = new UICommand("Cancel");
            promptDialog.Options = MessageDialogOptions.None;
            promptDialog.Commands.Add(commitCommand);
            promptDialog.Commands.Add(rollbackCommand);
            promptDialog.Commands.Add(cancelCommand);

            try
            {
                // Ask the user if they want to commit or rollback the transaction (or cancel to keep working in the transaction).
                IUICommand cmd = await promptDialog.ShowAsync();

                if (cmd.Label == commitCommand.Label)
                {
                    // See if there is a transaction active for the geodatabase.
                    if (_localGeodatabase.IsInTransaction)
                    {
                        // If there is, commit the transaction to store the edits (this will also end the transaction).
                        _localGeodatabase.CommitTransaction();
                        MessageTextBlock.Text = "Edits were committed to the local geodatabase.";
                    }
                }
                else if (cmd.Label == rollbackCommand.Label)
                {
                    // See if there is a transaction active for the geodatabase.
                    if (_localGeodatabase.IsInTransaction)
                    {
                        // If there is, rollback the transaction to discard the edits (this will also end the transaction).
                        _localGeodatabase.RollbackTransaction();
                        MessageTextBlock.Text = "Edits were rolled back and not stored to the local geodatabase.";
                    }
                }
                else
                {
                    // For 'cancel' don't end the transaction with a commit or rollback.
                }
            }
            catch
            {
            }
        }

        // Change which controls are enabled if the user chooses to require/not require transactions for edits.
        private void RequireTransactionChanged(object sender, RoutedEventArgs e)
        {
            // If the local geodatabase isn't created yet, return.
            if (_localGeodatabase == null) { return; }

            // Get the value of the "require transactions" checkbox.
            bool mustHaveTransaction = RequireTransactionCheckBox.IsChecked == true;

            // Warn the user if disabling transactions while a transaction is active.
            if (!mustHaveTransaction && _localGeodatabase.IsInTransaction)
            {
                _ = new MessageDialog2("Stop editing to end the current transaction.", "Current Transaction").ShowAsync();
                RequireTransactionCheckBox.IsChecked = true;
                return;
            }

            // Enable or disable controls according to the checkbox value.
            StartEditingButton.IsEnabled = mustHaveTransaction;
            StopEditingButton.IsEnabled = mustHaveTransaction && _localGeodatabase.IsInTransaction;
            AddBirdButton.IsEnabled = !mustHaveTransaction;
            AddMarineButton.IsEnabled = !mustHaveTransaction;
        }

        // Synchronize edits in the local geodatabase with the service.
        public async void SynchronizeEdits(object sender, RoutedEventArgs e)
        {
            // Show the progress bar while the sync is working.
            LoadingProgressBar.Visibility = Visibility.Visible;

            try
            {
                // Create a sync task with the URL of the feature service to sync.
                GeodatabaseSyncTask syncTask = await GeodatabaseSyncTask.CreateAsync(new Uri(SyncServiceUrl));

                // Create sync parameters.
                SyncGeodatabaseParameters taskParameters = await syncTask.CreateDefaultSyncGeodatabaseParametersAsync(_localGeodatabase);

                // Create a synchronize geodatabase job, pass in the parameters and the geodatabase.
                SyncGeodatabaseJob job = syncTask.SyncGeodatabase(taskParameters, _localGeodatabase);

                // Handle the JobChanged event for the job.
                job.StatusChanged += (s, arg) =>
                {
                    // Report changes in the job status.
                    if (job.Status == JobStatus.Succeeded)
                    {
                        // Report success ...
                        DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () => MessageTextBlock.Text = "Synchronization is complete!");
                    }
                    else if (job.Status == JobStatus.Failed)
                    {
                        // Report failure ...
                        DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () => MessageTextBlock.Text = job.Error.Message);
                    }
                    else
                    {
                        // Report that the job is in progress ...
                        DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () => MessageTextBlock.Text = "Sync in progress ...");
                    }
                };

                // Await the completion of the job.
                await job.GetResultAsync();
            }
            catch (Exception ex)
            {
                // Show the message if an exception occurred.
                MessageTextBlock.Text = "Error when synchronizing: " + ex.Message;
            }
            finally
            {
                // Hide the progress bar when the sync job is complete.
                LoadingProgressBar.Visibility = Visibility.Collapsed;
            }
        }
    }
}

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.