I created a new entry with breeze, on submit i want to immediately get the id of the record using the basic fields that i used to create the record like using email, please how do i get the Id of the new record using breeze.
this is what i have done
bind gotoStep2() with the save button which pass in the value of the textbox to use as predicate,
// the save() method successfully create the record to the database,
function gotoStep2(firstName, lastName, email) {
save();
console.log('Save log')
// Get the ProfileID
return datacontext.profile.getProfileId(firstName, lastName, email)
.then(function (data) {
console.log('Id retrived is: ' + data.Id); // check the value returned
vm.profile = data;
//$location.path('/step-two/' + data.Id);
// Todo: pass the value to the next route
}, function (error) {
logError('Unable to get speaker');
});
}
function getProfileId(firstName, lastName, email) {
var self = this;
var predicate = Predicate.create('firstName', '==', firstName)
.and('lastName', '==', lastName)
.and('email', '==', email);
var profiles = [];
return EntityQuery.from('Profiles')
.select('id')
.where(predicate)
.toType(entityName)
.using(self.manager).execute()
.then(querySucceeded, self._queryFailed);
function querySucceeded(data) {
profiles = data.results;
self.log('Retrieved [Profile by email] from remote data source', profiles.length, true);
return profiles;
}
}
from the above query dont always get any return value
Thanks
Not entirely sure I understand your question, but it sounds like you want to get the id of a newly saved record immediately after the save. If so then the answer below applies.
When the save promise resolves it returns both the list of saved entities as well as a keyMappings array for any entities whose ids changed as a result of the save. i.e. a mapping from temporary to real ids. i.e. (Documented here: http://www.breezejs.com/sites/all/apidocs/classes/EntityManager.html#method_saveChanges)
myEntityManager.saveChanges().then(function (saveResult) {
// entities is an array of entities that were just saved.
var entitites = saveResult.entities;
var keyMappings = saveResult.keyMappings;
keyMappings.forEach(function(km) {
var tempId = km.tempValue;
var newId = km.realValue;
});
});
On the other hand if you have an entity and you just want its 'key' you can use the EntityAspect.getKey method. (see http://www.breezejs.com/sites/all/apidocs/classes/EntityAspect.html#method_getKey)
// assume order is an order entity attached to an EntityManager.
var entityKey = order.entityAspect.getKey();
Related
Currently I am doing like this:
For Example:
public update(Person model)
{
// Here model is model return from form on post
var oldobj = db.Person.where(x=>x.ID = model.ID).SingleOrDefault();
db.Entry(oldobj).CurrentValues.SetValues(model);
}
It works, but for example,
I have 50 columns in my table but I displayed only 25 fields in my form (I need to partially update my table, with remaining 25 column retain same old value)
I know it can be achieve by "mapping columns one by one" or by creating "hidden fields for those remaining 25 columns".
Just wondering is there any elegant way to do this with less effort and optimal performance?
This is a very good question. By default I have found that as long as change tracking is enabled (it is by default unless you turn it off), Entity Framework will do a good job of applying to the database only what you ask it to change.
So if you only change 1 field against the object and then call SaveChanges(), EF will only update that 1 field when you call SaveChanges().
The problem here is that when you map a view model into an entity object, all of the values get overwritten. Here is my way of handling this:
In this example, you have a single entity called Person:
Person
======
Id - int
FirstName - varchar
Surname - varchar
Dob - smalldatetime
Now let's say we want to create a view model which will only update Dob, and leave all other fields exactly how they are, here is how I do that.
First, create a view model:
public class PersonDobVm
{
public int Id { get; set; }
public DateTime Dob { get; set; }
public void MapToModel(Person p)
{
p.Dob = Dob;
}
}
Now write the code roughly as follows (you'll have to alter it to match your context name etc):
DataContext db = new DataContext();
Person p = db.People.FirstOrDefault();
// you would have this posted in, but we are creating it here just for illustration
var vm = new PersonDobVm
{
Id = p.Id, // the Id you want to update
Dob = new DateTime(2015, 1, 1) // the new DOB for that row
};
vm.MapToModel(p);
db.SaveChanges();
The MapToModel method could be even more complicated and do all kinds of additional checks before assigning the view model fields to the entity object.
Anyway, the result when SaveChanges is called is the following SQL:
exec sp_executesql N'UPDATE [dbo].[Person]
SET [Dob] = #0
WHERE ([Id] = #1)
',N'#0 datetime2(7),#1 int',#0='2015-01-01 00:00:00',#1=1
So you can clearly see, Entity Framework has not attempted to update any other fields - just the Dob field.
I know in your example you want to avoid coding each assignment by hand, but I think this is the best way. You tuck it all away in your VM so it does not litter your main code, and this way you can cater for specific needs (i.e. composite types in there, data validation, etc). The other option is to use an AutoMapper, but I do not think they are safe. If you use an AutoMapper and spelt "Dob" as "Doob" in your VM, it would not map "Doob" to "Dob", nor would it tell you about it! It would fail silently, the user would think everything was ok, but the change would not be saved.
Whereas if you spelt "Dob" as "Doob" in your VM, the compiler will alert you that the MapToModel() is referencing "Dob" but you only have a property in your VM called "Doob".
I hope this helps you.
I swear by EntityFramework.Extended. Nuget Link
It lets you write:
db.Person
.Where(x => x.ID == model.ID)
.Update(p => new Person()
{
Name = newName,
EditCount = p.EditCount+1
});
Which is very clearly translated into SQL.
Please try this way
public update(Person model)
{
// Here model is model return from form on post
var oldobj = db.Person.where(x=>x.ID = model.ID).SingleOrDefault();
// Newly Inserted Code
var UpdatedObj = (Person) Entity.CheckUpdateObject(oldobj, model);
db.Entry(oldobj).CurrentValues.SetValues(UpdatedObj);
}
public static object CheckUpdateObject(object originalObj, object updateObj)
{
foreach (var property in updateObj.GetType().GetProperties())
{
if (property.GetValue(updateObj, null) == null)
{
property.SetValue(updateObj,originalObj.GetType().GetProperty(property.Name)
.GetValue(originalObj, null));
}
}
return updateObj;
}
I have solved my Issue by using FormCollection to list out used element in form, and only change those columns in database.
I have provided my code sample below; Great if it can help someone else
// Here
// collection = FormCollection from Post
// model = View Model for Person
var result = db.Person.Where(x => x.ID == model.ID).SingleOrDefault();
if (result != null)
{
List<string> formcollist = new List<string>();
foreach (var key in collection.ToArray<string>())
{
// Here apply your filter code to remove system properties if any
formcollist.Add(key);
}
foreach (var prop in result.GetType().GetProperties())
{
if( formcollist.Contains(prop.Name))
{
prop.SetValue(result, model.GetType().GetProperty(prop.Name).GetValue(model, null));
}
}
db.SaveChanges();
}
I still didn't find a nice solution for my problem, so I created a work around. When loading the Entity, I directly make a copy of it and name it entityInit. When saving the Entity, I compare the both to see, what really was changed. All the unchanged Properties, I set to unchanged and fill them with the Database-Values. This was necessary for my Entities without Tracking:
// load entity without tracking
var entityWithoutTracking = Context.Person.AsNoTracking().FirstOrDefault(x => x.ID == _entity.ID);
var entityInit = CopyEntity(entityWithoutTracking);
// do business logic and change entity
entityWithoutTracking.surname = newValue;
// for saving, find entity in context
var entity = Context.Person.FirstOrDefault(x => x.ID == _entity.ID);
var entry = Context.Entry(entity);
entry.CurrentValues.SetValues(entityWithoutTracking);
entry.State = EntityState.Modified;
// get List of all changed properties (in my case these are all existing properties, including those which shouldn't have changed)
var changedPropertiesList = entry.CurrentValues.PropertyNames.Where(x => entry.Property(x).IsModified).ToList();
foreach (var checkProperty in changedPropertiesList)
{
try
{
var p1 = entityWithoutTracking.GetType().GetProperty(checkProperty).GetValue(entityWithoutTracking);
var p2 = entityInit.GetType().GetProperty(checkProperty).GetValue(entityInit);
if ((p1 == null && p2 == null) || p1.Equals(p2))
{
entry.Property(checkProperty).CurrentValue = entry.Property(checkProperty).OriginalValue; // restore DB-Value
entry.Property(checkProperty).IsModified = false; // throws Exception for Primary Keys
}
} catch(Exception) { }
}
Context.SaveChanges(); // only surname will be updated
This is way I did it, assuming the new object has more columns to update that the one we want to keep.
if (theClass.ClassId == 0)
{
theClass.CreatedOn = DateTime.Now;
context.theClasses.Add(theClass);
}
else {
var currentClass = context.theClasses.Where(c => c.ClassId == theClass.ClassId)
.Select(c => new TheClasses {
CreatedOn = c.CreatedOn
// Add here others fields you want to keep as the original record
}).FirstOrDefault();
theClass.CreatedOn = currentClass.CreatedOn;
// The new class will replace the current, all fields
context.theClasses.Add(theClass);
context.Entry(theClass).State = EntityState.Modified;
}
context.SaveChanges();
In EF you can do like this
var result = db.Person.Where(x => x.ID == model.ID).FirstOrDefault();
if(result != null){
result.Name = newName;
result.DOB = newDOB;
db.Person.Update(result);
}
Or you can use
using (var db= new MyDbContext())
{
var result= db.Person.Where(x => x.ID == model.ID).FirstOrDefault();
result.Name= newName;
result.DOB = newDOB;
db.Update(result);
db.SaveChanges();
}
For more detail please EntityFramework Core - Update Only One Field
No Worry guys
Just write raw sql query
db.Database.ExecuteSqlCommand("Update Person set Name='"+_entity.Name+"' where Id = " + _entity.ID + "");
I can execute a query in breeze from the server (using EF) which returns a load of boostrap data thus:
em.executeQuery(_lookupsQuery).then(function (data) {
_lookups = data.results;
console.log(_lookups[0].currentUserId);
This returns currentUserId which is a guid. I then store em using local storage for querying locally later:
_lookups = [{
currentUserId: em.executeQueryLocally(_lookupsQuery.toType(breeze.DataType.String))
}];
However this does not work as it requires an entity type e.g:
em.executeQueryLocally(_lookupsQuery.toType(em.metadataStore.getEntityType("Measure")))
Since currentUserId is a guid I am not sure which type to cast the query to. I have tried to make an entity type on the client just for this but it does not seem to work. Any help on solving this would be appreciated.
Edit:
After a suggestion, I modified lookups:
[HttpGet]
public async Task<object> Lookups()
{
var currentUser = await UserManager.FindById(Guid.Parse(User.Identity.GetUserId()));
var companyId = currentUser.CompanyId.Value;
return new
{
currentUser = new
{
Id = currentUser.Id
}
};
}
When querying remotely using:
em.executeQuery(_lookupsQuery).then(function (data) {
_lookups = data.results;
console.log(_lookups[0].currentUser);
I get:
Object { id="f2dceb4b-29e7-4533-99e2-2052dc39143a"}
I set up the new entity type:
metadataStore.addEntityType({
shortName: "CurrentUser",
dataProperties: {
id: { dataType: "String", isPartOfKey: true }
}
});
but when I query locally:
_lookups = [{
currentUser: em.executeQueryLocally(_lookupsQuery.toType(em.metadataStore.getEntityType("CurrentUser"))) }];
console.log(_lookups[0].currentUser);
this returns []
What am I doing wrong?
There are a few ways you can handle it. I am only going to touch on the two most basic methods that I personally use and hopefully one sparks your interest.
-1. Create an entityType in your metadataStore for user-type information.
metadataStore.addEntityType({
shortName: "User",
dataProperties: {
userId: { dataType: "String", isPartOfKey: true },
userName: { dataType: "String" }
}
});
This will add an entity type that you can serialize your return results to. It is important to note here that if you change anything about that user without accepting changes locally it will try to save it next time you call saveChanges() so make sure you handle those situations if applicable.
Of course that isn't the only option. You can most certainly just grab that user id from the query results without Breeze ever knowing about it or what it is for.
-2. POJO
function user(data) {
var self = this;
self.UserId = data.userId;
self.UserName = data.userName;
}
// After your query returns data
query.execute().then(userReturned);
function userReturned(data) {
// data is the returned object, which contains
// an httpResponse which is what breeze returns
// as the raw response
new user(data.httpResponse.data);
}
This method basically just grabs the httpResponse when the promise returns and uses it to create a Plain Old JavaScript Object without Breeze knowing about it. Of course for this to work you need to examine your data object that is returned and find what you are looking for and serialize that.
Edit
Your query locally should look like this -
query = breeze.entityQuery().from("Whatever").toType("CurrentUser").executeLocally();
em.executeQueryLocally(query);
Is the essence of Project, the creation of which is necessary to check whether there is already an entity with the same name. When editing needs such as checking, but keep in mind that the old and the new name of the entity can be matched.
You also need to display an error message. For this I use interface IValidatableObject, but do not know how to tell the Validate method the object is currently being edited or created
DbContext.ValidateEntity takes the IDictionary<Object, Object> items as the second parameter. You can pass any data there and the data you pass will be passed to IValidatableObject.Validate in the ValidationContext.Items
Assuming you refer to check EF cant do for you.
This is actually difficult to check. You are checking an entity after it has been added to the context. It should not check itself and needs to consider other items in context that are not yet saved. As well as the DB. There are several 3 combinations plus an self recognition. Record a an entity record in LOCAL when ID is blank/new ie multiple new inserts needs careful coding. (Consider using temp IDs)
the not yet saved entries should be in context
Context.Set<TPoco>().Local
and get data from DB and keep in a temp list. BUT dont put in context.
Or use a SECOND context.
var matchingSet = Context.Set<TPoco>().AsNoTracking() // not into context...
.Where(t=>t.field == somevalue).ToList();
So what about logical and actual duplicates on the DB. Logical duplicates are duplicates on a field with no unique index that from a business perspective should be unique.
If you want to check those...
You need to read the DB.... BUT if these records are currently being changed, you CAN NOT just put them into the Context. You would overwrite them.
But what if the values the logical key values have changed?
Something caused a logical dup on a record on the DB may no longer be a dup once saved or vice verse. Is that still a dup or not ?
So you need to decide how you match LOCAL versus loaded records.
Ie check LOCAL and matching DB records and decidr what to do if a record is in both, only local or only db.
LOCAL ONLY and DB Only is easy.
But in both... That is your business process decision.
Problem is solved using method ModelState.AddModelError (string, string) in actions Edit and Create.
[HttpPost]
[HandleError(View="AjaxError")]
public ActionResult Edit(ProjectsViewData data)
{
if (ModelState.IsValid)
{
if (!ContainsProject(data.CurrentObject.Name))
{
db.Projects.Attach(data.CurrentObject);
db.ObjectStateManager.ChangeObjectState(data.CurrentObject, EntityState.Modified);
db.SaveChanges();
return Projects(data);
}
else
{
int projectId = (from p in db.Projects
where p.Name == data.CurrentObject.Name
select p.ProjectID).FirstOrDefault();
if (projectId == data.CurrentObject.ProjectID)
{
db.Projects.Attach(data.CurrentObject);
db.ObjectStateManager.ChangeObjectState(data.CurrentObject, EntityState.Modified);
db.SaveChanges();
return Projects(data);
}
else
{
ModelState.AddModelError("Name", Localizer.ProjectAlreadyExists);
}
}
}
data.ObjectToEdit = data.CurrentObject;
return Projects(data);
}
[HttpPost]
[HandleError(View = "AjaxError")]
public ActionResult Create(ProjectsViewData data)
{
if (ModelState.IsValid)
{
if (!ContainsProject(data.CurrentObject.Name))
{
db.Projects.AddObject(data.CurrentObject);
db.SaveChanges();
return Projects(data);
}
else
{
ModelState.AddModelError("Name", Localizer.ProjectAlreadyExists);
}
}
data.ObjectToAdd = data.CurrentObject;
return Projects(data);
}
Helper method:
private bool ContainsProject(string projectName)
{
if (projectName != null)
{
projectName = Regex.Replace(projectName.Trim(), "\\s+", " ");
List<string> projects = new List<string>();
var projectNames = (from p in db.Projects
select p.Name.Trim()).ToList();
foreach (string p in projectNames)
{
projects.Add(Regex.Replace(p, "\\s+", " "));
}
if (projects.Contains(projectName))
{
return true;
}
else
{
return false;
}
}
else
{
return false;
}
}
Problem
I have a view with 6 drop downs. Each of which is being populated by a Web API call. I want
to use breeze to run the query locally once it has populated from the remote server
The code runs fine when the data call is against the server. The issue is when trying to query the local cache. I never get any results returned. Is my approach flawed or am I doing something wrong ?
SERVER SIDE
View model
class genericDropDown()
{
public int value{get;set;}
public string option{get;set;}
}
The WebAPI [A single sample method]
[HttpGet]
// GET api/<controller>
public object GetSomeVals()
{
return _context.getClinician();
}
The Repository [A single sample method]
public IEnumerable<genericDropDown> getDropDownVal()
{
return context.somemodel(a=>new{a.id,a.firstname,a.lastname}).ToList().
Select(x => new GenericDropDown
{ value = x.id, option = x.firstname+ " " + x.lastname});}
}
CLIENT SIDE
Datacontext.js
var _manager = new breeze.EntityManager("EndPoint");
//Being called from my view model
var getDropDownBindings = function(KO1, KO2) {
//First add the entity to the local metadatastore then populate the entity
$.when(
addDD('clinicianDropDown', webAPIMethod),
getData(KO1, webAPIMethod, null, 'clinicianDropDown'),
addDD('docTypeDropDown', webAPIMethod);
getData(KO2, webAPIMethod, null, 'docTypeDropDown'),
).then(querySucceeded).fail(queryFailed);
function querySucceeded(data) {
logger.log('Got drop down vals', "", 'dataContext', true);
}
};
//Add the entity to local store. First param is typename and second is
resource name (Web API method)
var addDD = function(shortName,resName) {
_manager.metadataStore.addEntityType({
shortName: shortName,
namespace: "Namespace",
autoGeneratedKeyType: breeze.AutoGeneratedKeyType.Identity,
defaultResourceName:resName,
dataProperties: {
value: { dataType: DataType.Int32,
isNullable: false, isPartOfKey: true },
option: { dataType: DataType.String, isNullable: false }
}
});
return _manager.metadataStore.registerEntityTypeCtor(shortName, null, null);
};
//Get the data
var getData = function(observableArray, dataEndPoint, parameters, mapto) {
if (observableArray != null)
observableArray([]);
//TO DO: Incorporate logic for server or local call depending on
// whether this method is accessed for the first time
var query = breeze.EntityQuery.from(dataEndPoint);
if (mapto != null && mapto != "")
query = query.toType(mapto);
if (parameters != null)
query = query.withParameters(parameters);
//This approach doesnt work on local querying as Jquery complains
//there is no 'then' method. Not sure how to implement promises
//when querying locally
/* return _manager.executeQuery(query).then(querySucceeded).fail(queryFailed);
function querySucceeded(data) {
if (observableArray != null)
observableArray(data.results);
}
*/
//The array length from this query is always 0
var data = _manager.executeQueryLocally(query);
observableArray(data.results);
return;
};
//Generic error handler
function queryFailed(error) {
logger.log(error.message, null, 'dataContext', true);
}
viewmodel.js
//In Durandal's activate method populate the observable arrays
dataContext.getDropDownBindings (KO1,KO2);
Viewmodel.html
<select class="dropdown" data-bind="options: KO1, optionsText: 'option', value: 'value', optionsCaption: 'Clinicians'"></select>
<select class="dropdown" data-bind="options: KO2 optionsText: 'option', value: 'value', optionsCaption: 'Document Types'"></select>
You can only execute local queries against types that are described by metadata.
Without more information I can't be sure, but my guess is that your GetSomeVals method is not returning 'entities' but just loose data. In other words, the types of objects returned from the GetSomeVals method must be entities (or contain entities within a projection) in order for breeze to be able to perform a local query. This is because Breeze knows how to cache and query entities but has no ideas how to cache 'arbitrary' query results.
Note that you can return an anonymous type containing entities of different types from the server, (in order to populate mostly static small datasets), but the individual items must be 'entities'. In this case, Breeze will take apart the anon result and pick out any entities to include in the EntityManager cache.
Per you question of how to perform an local query with promises, use the FetchStrategy.FromLocalCache with the using method.
i.e. this query
var results = em.executeQueryLocally(query)
can also be expressed as:
query = query.using(FetchStrategy.FromLocalCache);
return em.executeQuery(query).then(data) {
var results = data.results;
}
The local query is still executed synchonously but is made to look async.
I develop an application with asp.net mvc + breeze.
So far, I retrieve a specific record (based on id) like this:
var getTransportById = function (transportId, transportObservable) {
return manager.fetchEntityByKey('Transport', transportId, true)
.then(fetchSucceeded)
.fail(queryFailed);
}
function fetchSucceeded(data) {
var s = data.entity;
return ...
}
Now I need to retrieve the same record but need to 'expand' the property named sender which links to another entity (table). I did not find a way to 'expand' one property through fetchEntityByKey so I used a query like this:
var getTransportById = function (transportId, transportObservable) {
var query = EntityQuery.from('Transports')
.where('id', 'eq', transportId)
.expand('Sender')
.orderBy(orderBy.transport);
return manager.executeQuery(query)
.then(fetchSucceeded)
.fail(queryFailed);
}
function fetchSucceeded(data) {
var s = data.results[0];
return ...
}
My question: is it the good way to proceed? Is there another way of doing?
Thanks.
You can create a query from an EntityKey and then expand whichever properties you want. Something like this:
var entityKey = new EntityKey("Transport", transportId);
// expand whichever nav props you want here.
var query = EntityQuery.fromEntityKey(entityKey).expand("Sender").orderBy(...);
return entityManager.executeQuery(query).then( {
...
});