I am new to BreezeJS and would like to know if there are any examples on how to use Breeze with an SQL Stored Procedure?
We have some pretty complex queries and want to be able to call them via an SP. Also, how can we tell Breeze that a column returned from a SP is the Key? We don't want to use Views, because we need to pass variables to the SP query each time we call it.
Thanks.
bob
Ok, the basic idea would be to use Breeze's EntityQuery.withParameters method to pass parameters to a server side method that calls your stored proc and returns an IEnumerable. ( i.e. the result of the stored proc).
If you want to treat this result as collection of Breeze entities then you will either need to shape the results into an existing entity type that Breeze knows about from Metadata OR manually create and add a new EntityType on the client that matches the shape that you want to return.
You may want to look at the EntityQuery.toType method to force breeze to convert your returned data into a specific EntityType or you might alternately want to use a "jsonResultsAdapter" to do the same thing.
Any data that is returned from a query and is converted into an Breeze EntityType is automatically wrapped according the "modelLibrary" in use, i.e. Knockout, Angular, Backbone etc.
If breeze is not able to construct entities out of the returned data then it will still be returned but without any special processing to wrap the result.
Hope this helps!
A sample to access Sql Stored Procedures from Breeze; the store procedure (GoStoCde) has been imported by EF.
Breeze Controller :
[HttpGet]
public object GetCdes(long jprod, int jqte, long jorder)
{
//output params
var owrk = new System.Data.Objects.ObjectParameter("wkres", typeof(string));
owrk.Value = "";
var oeror = new System.Data.Objects.ObjectParameter("ceror", typeof(int));
oeror.Value = 0;
//invoke stored procedure
var envocde = _contextProvider.Context.GoStoCde(jprod, jqte, jorder, owrk, oeror);
//stored procedure results
var cdeResult = new {
dwork = owrk.Value,
deror = oeror.Value,
};
return new { cdeResult };
}
Datacontext :
function reqLnecde(iprod, iqte, iorder, vxeror) {
logger.log("commande en cours...");
var query = new EntityQuery.from("GetCdes")
.withParameters({ jprod: iprod, jqte: iqte, jorder: iorder });
return manager
.executeQuery(query)
.then(querySucceeded)
.fail(cqueryFailed);
function querySucceeded(data) {
//stored procedure results
vxeror(data.results[0]);
//stored procedure object member value
keror = vxeror().cdeResult.deror;
if (keror === 0) {
logger.log("commande done");
} else {
logger.log("article absent");
}
}
function queryFailed(data) {
logger.log("commande failed"); //server errors
}
}
If you prefer to return entity in lieu of object, code consequently and its must also work.
Hope this helps!
Not really an answer here, just a few thoughts.
I think that the ability to return arbitrarily shaped data (read viewmodel) through the use of a stored procedure using withParameters would be an excellent way to inegerate with something like dapper.net. Upon resubmission of said viewmodel you could use the overloads to reconstruct actual entities out of your viewmodel and save changes. The only problem I have though is that one would need a way to easily and automaticaly rerun the sproc and send the data back to the client...
I would like to know if this makes sense to anyone else and/or if anyone has done it already.
For this sort of scenario I would think that you would need to disable the tracking features provided by breeze and/or write a smart enough data service that can handle the viewmodels in such a way that the javascript on the client knows when adding/removing/updating parts x,y,z of viewmodel a that you create objects jx, jy, jz (j for javascript) and submit them back and save as you go (reverse idea of what was mentioned above in a way)
Thoughts?
Related
Hiy!
I want all objects(rows in Test Type) with ModelService
So I could iterate through collection and update a Single row (object)'s attribute with new value
I see getModelService.create(TestModel.class) and getModelService.save()
but will they not create a new object/row rather than update a existing object?right
I don't want to create a new one rather selecting one of the existing matching my criteria and update one attribute of that
can somebody help with List<TestModel> testModels = getModelService.get(TestModel.class) will that return me all rows (collection) of Test Type/Table?
unfortunately I can't test it so need help
Actually I am in validateInterceptor ... and on the basis of this intercepted model changed attribute value I have to update another model attribute value...
thanks
ModelService.create(new TestModel.class) will create a single instance of the specified type and attach it to the modelservice's context.
But it will only be saved to the persistence store when you call modelService.save(newInstance)
ModelService.get() returns a model object but expects a Jalo object as input, (Jalo being the legacy persistence layer of hybris) so that won't work for you.
To retrieve objects you can either write your own queries using the FlexibleSearchService or you can have a look at the DefaultGenericDao which has a bunch of simple find() type of methods.
Typically you would inject the dao like e.g.:
private GenericDao<TestModel> dao;
[...]
public void myMethod()
{
List<TestModel> allTestModels = dao.find();
[...]
}
There are a lot more methods with which you can create WHERE type of statements to restrict your result.
Regarding ValidateInterceptor:
Have a look at the wiki page for the lifecycle of interceptors:
https://wiki.hybris.com/display/release5/Interceptors
It's not a good idea to modify 'all' objects of a type while being an interceptor of that type.
So if you're in an interceptor declared for the Test item type, then don't try to modify the items there.
If you happen to be in a different interceptor and want to modify items of a different type:
E.g. you have Type1 which has a list of Type2 objects in it and in the interceptor for Type1 you want to modify all Type2 objects.
For those scenarios you would have to add the instances of Type2 that you modify to the interceptor context so that those changes will be persisted.
That would be something like:
void onValidate(Test1 model, InterceptorContext ctx) throws InterceptorException
{
...
List<Type2> type2s = dao.find();
for (Type2 type2 : type2s)
{
// do something with it
// then make sure to persist that change
ctx.registerElementFor(type2, PersistenceOperation.SAVE);
[...]
}
}
First of all - i think it's not a good idea, to create/update models in any interceptor, especially in 'validation' one.
Regarding your question:
ModelService in most of the cases works with single model, and
designed for create/update/delete operations.
To retreive all models of certain type, you have to use FlexibleSearchService
Then to update each retrieved TestType model, you can use ModelService's save method.
A query to retreive all TestType models will look like:
SELECT PK FROM {TestType}
You could simply use the Flexible Search Service search by example method, and the model service to save them all. Here is an example using Groovy script, with all products :
import java.util.List
import de.hybris.platform.core.model.product.ProductModel
import de.hybris.platform.servicelayer.search.FlexibleSearchService
import de.hybris.platform.servicelayer.model.ModelService
FlexibleSearchService fsq = spring.getBean("flexibleSearchService")
ModelService ms = spring.getBean("modelService")
ProductModel prd = ms.create(ProductModel.class)
List<ProductModel> products = fsq.getModelsByExample(prd)
//Do Whatever you want with the objects in the List
ms.saveAll(products)
Is there any way to define the SQL conversion component for additional functions to Linq2Entities.
For example:
myQuery.Where(entity => entity.Contains('foo', SearchFlags.All))
Ideally I am looking for something that doesn't require editing and building a new version the EntityFramework.dll directly. Is there any way to allow extension methods to entity framework that can support SQL generation.
So far I have a template which would represent the method I need to replace for LINQ to Entities:
public static bool Contains(this object source, string searchTerms, SearchFlags flags)
{
return true;
}
Of course this causes the error:
LINQ to Entities does not recognize the method 'Boolean
CONTAINS(System.Object, System.String, SearchFlags)' method, and this method
cannot be translated into a store expression.
To be clear, I don't want to do:
myQuery.AsEnumerable().Where(entity => entity.Contains('foo', SearchFlags.All))
Because I want to be able to execute code in SQL space and not return all the entities manually.
I also cannot use the .ToString() of the IQueryable and execute it manually because I need Entity Framework to populate the objects from several .Include joins.
I don't understand your Q clearly. However if your problem is that you can't use your own methods or other linq to objects method, just use .AsEnumerable() and do your other jobs through linq to objects, not L2E:
myQuery.AsEnumerable().Where(entity => entity.Contains('foo', SearchFlags.All))
And if you need to use your myQuery several times somewhere else, first load it to memory, then use it as many as you want:
var myQuery = from e in context.myEntities
select d;
myQuery.Load();
// ...
var myOtherQuery = from d in context.myEntities.Local
select d;
// Now any L2O method is supported...
I ended up doing the following (which works but is very far from perfect):
All my entities inherit from an IEntity which defines long Id { get; set; }
I then added a redundant restriction
context.myEntities.Where(entity => entity.Id != 0) this is
redundant since the identity starts at 1, but Linq2Entities doesn't
know that.
I then call .ToString() on the IQueryable after I have done all
my other queries, since it is of type DBQuery<Entity> it returns
the SQL Command Text, I do a simple replace with my query restriction.
In order to get all the .Include(...) to work I actually execute
two different sql commands. There is no other more pretty way to tap into this because of query execution plan caching causes issues otherwise (even when disabled).
As a result my code looks like this:
public IQueryable<IEntity> MyNewFunction(IQueryable<IEntity> myQueryable, string queryRestriction)
{
string rawSQL = myQueryable.Select(entity => entity.Id).ToString().Replace("[Extent1].Id <> 0", queryRestriction);
List<long> ids = // now execute rawSQL, get the list of ids;
return myQuerable.Where(entity => ids.Contains(entity.Id));
}
In short, other than manually executing the SQL or running a similar SQL command and appending the restriction using the existing commands the only way to write your own methods to Linq-to-Entities is to manually alter and build your own EntityFramework.dll from the EF6 source.
So I'm trying to prevent a race condition between applications.
Using IsolationLevel/TransactionScope, I can lock the table the way I need to, but need to run the update operation first, then operate on the list of modified objects.
To do this, I need to run the update and get the list of updated ID's all in one shot.
If I were to try to take the IDs first, that wouldn't lock the table, and another app instance could query for that same list, before they were flagged.
Is there a way to do something like:
//modify some objects
var updatedIds = context.SaveChanges();
//Process updatedIds
Is there a way to do this? I've tried looking through the ObjectContext entries, but after the Save there doesn't seem to be anything.
Maybe I'll have to do an sproc?
This code can go into your Context class and should give you what you need
public override int SaveChanges()
{
using (var scope = new System.Transactions.TransactionScope())
{
//pre processing
var result = base.SaveChanges();
//post processing
scope.Complete();
return result;
}
}
I have recently started evaluating Dapper as a potential replacement for EF, since I was not too pleased with the SQL that was being generated and wanted more control over it. I have a question regarding mapping a complex object in my domain model. Let's say I have an object called Provider, Provider can contain several properties of type IEnumerable that should only be accessed by going through the parent provider object (i.e. aggregate root). I have seen similar posts that have explained using the QueryMultiple and a Map extension method but was wondering how if I wanted to write a method that would bring back the entire object graph eager loaded, if Dapper would be able to do this in one fell swoop or if it needed to be done piece-meal. As an example lets say that my object looked something like the following:
public AggregateRoot
{
public int Id {get;set;}
...//simple properties
public IEnumerable<Foo> Foos
public IEnumerable<Bar> Bars
public IEnumerable<FooBar> FooBars
public SomeOtherEntity Entity
...
}
Is there a straightforward way of populating the entire object graph using Dapper?
I have a similar situation. I made my sql return flat, so that all the sub objects come back. Then I use the Query<> to map the full set. I'm not sure how big your sets are.
So something like this:
var cnn = sqlconnection();
var results = cnn.Query<AggregateRoot,Foo,Bars,FooBar,someOtherEntity,AggregateRoot>("sqlsomething"
(ar,f,b,fb,soe)=>{
ar.Foo = f;
ar.Bars = b;
ar.FooBar = fb;
ar.someotherentity = soe;
return ar;
},.....,spliton:"").FirstOrDefault();
So the last object in the Query tag is the return object. For the SplitOn, you have to think of the return as a flat array that the mapping will run though. You would pick the first return value for each new object so that the new mapping would start there.
example:
select ID,fooid, foo1,foo2,BarName,barsomething,foobarid foobaritem1,foobaritem2 from blah
The spliton would be "ID,fooid,BarName,foobarid". As it ran over the return set, it will map the properties that it can find in each object.
I hope that this helps, and that your return set is not too big to return flat.
Time and again I find myself creating a database utility class which has multiple functions which all do almost the same thing but treat the result set slightly differently.
For example, consider a Java class which has many functions which all look like this:
public void doSomeDatabaseOperation() {
Connection con = DriverManager.getConnection("jdbc:mydriver", "user", "pass");
try {
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT whatever FROM table"); // query will be different each time
while (rs.next()) {
// handle result set - differently each time
}
} catch (Exception e) {
// handle
} finally {
con.close();
}
}
Now imagine a class with 20 of these functions.
As you can see, tons of boilerplate (opening a connection, try-finally block), and the only thing that changes would be the query and the way you handle the result set. This type of code occurs in many languages (considering you're not using an ORM).
How do you manage your DB utility classes so as to reduce code duplication? What does a typical DB utility class look like in your language/framework?
The way I have done in one of my project is that I followed what Spring does with JDBC template and came up with a Query framework. Basically create a common class which can take select statement or pl/sql calls and bind parameters. If the query returns resultset, also pass the Rowmapper. This rowmapper object will be called by the framework to convert each row into an object of any kind.
Example -
Query execute = new Query("{any select or pl/sql}",
// Inputs and Outputs are for bind variables.
new SQL.Inputs(Integer.class, ...),
// Outputs is only meaningful for PL/SQL since the
// ResultSetMetaData should be used to obtain queried columns.
new SQL.Outputs(String.class));
If you want the rowmapper -
Query execute = new Query("{any select or pl/sql}",
// Inputs and Outputs are for bind variables.
new SQL.Inputs(Integer.class, ...),
// Outputs is only meaningful for PL/SQL since the
// ResultSetMetaData should be used to obtain queried columns.
new SQL.Outputs(String.class), new RowMapper() {
public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
Actor actor = new Actor();
actor.setFirstName(rs.getString("first_name"));
actor.setSurname(rs.getString("surname"));
return actor;
});
Finally a Row class is the output which will have list of objects if you have passed the RowMapper -
for (Row r : execute.query(conn, id)) {
// Handle the rows
}
You can go fancy and use Templates so that type safety is guaranteed.
Sounds like you could make use of a Template Method pattern here. That would allow you to define the common steps (and default implementations of them, where applicable) that all subclasses will take to perform the action. Then subclasses need only override the steps which differ: SQL query, DB-field-to-object-field mapping, etc.
When using .net, the Data Access Application Block is in fairly widespread use to provide support for the following:
The [data access] application block
was designed to achieve the following
goals:
Encapsulate the logic used to perform
the most common data access tasks.
Eliminate common coding errors, such
as failing to close connections.
Relieve developers of the need to
write duplicated code for common data
access tasks.
Reduce the need for
custom code.
Incorporate best
practices for data access, as
described in the .NET Data Access
Architecture Guide.
Ensure that, as
far as possible, the application block
functions work with different types of
databases.
Ensure that applications
written for one type of database are,
in terms of data access, the same as
applications written for another type
of database.
There are plenty of examples and tutorials of usage too: a google search will find msdn.microsoft, 4guysfromrolla.com, codersource.com and others.