Relationship Quotes: Quotes About Relationships
Find inspiring relationship quotes that will remind you of the importance of relationships in our lives. In life and business, relationships are important - but. The Entity Relationship Model: Programming Against a Model, .. Building Extension Methods to Overload GetObjectStateEntries. Building a quote is that using JOINs should not be your first stab at expressing a query. I've seen. Note that the current values contain the entries for an added relationship and the original values contain the .. GetObjectStateEntry((EntityKey)objectStateEntry.
Being with you is the only way I could have a full and happy life. Like I can do anything. A dream you dream together is reality. There's no logic to these things. You meet someone and you fall in love and that's that. It is a person. And we are finally home. But the sense of camaraderie that comes with a lasting relationship? These strong relationship quotes will have your heart skipping a beat.
It will not do. My feelings will not be repressed. You must allow me to tell you how ardently I admire and love you. You will wish that it was. You can transmute love, ignore it, muddle it, but you can never pull it out of you. I know by experience that the poets are right: When we try to control it, it destroys us.
When we try to imprison it, it enslaves us. When we try to understand it, it leaves us feeling lost and confused. But finding a true soul mate is an even better feeling. A soul mate is someone who understands you like no other, loves you like no other, will be there for you forever, no matter what. They say that nothing lasts forever, but I am a firm believer in the fact that for some, love lives on even after we're gone.
I couldn't even believe it. That was the biggest thing to me. I'd never known anything like the friendship that I had with him. I could like him as much as I loved him. The confidence he has brings it to me. That's the way you should be with your partner. Contact to Addresses is a one-to-many relationship and Addresses is a collection of Address entities, not a single entity. Street is not a property of the Addresses EntityCollection.
However, you could select Address. LastName, because you would be navigating to a single entity. There is only one contact per address; therefore, there is no question regarding from which entity the query should retrieve the LastName.
The entity you are pointing to is referred to as an EntityReference, sometimes called an EntityRef. If you want to be sure the property is called Address you can use that instead of the simpler a, or use LINQ syntax to rename the property: Address in the data which results. Although this may suit many scenarios in your applications, you may prefer to project individual properties from the reference navigation.
Advanced Use Cases for the Repository Pattern in .NET
This projection returns a new type with three properties. The first is an Address entity; the second and third are strings. Again, the property names are based on the query defaults—a, FirstName, and LastName. For example, you can select all addresses for contacts with a particular last name. LastName and filters on the Contact. AddDate field even though AddDate is not part of the results. Filtering and sorting on reference properties from a in context. DateTime1, 1 orderby a. Count ; foreach var foo in contact.
Shaped results You could shape the data similar to the previous example, but instead of a set of complete address entities as the Foos property, you can project some of the address properties.
This would result in a set of anonymous types, named StreetsCities instead of Foos, in the second property. Projecting values from an EntityCollection from c in context. The newly shaped anonymous type Flattened results Another way to project into the addresses is to merely turn the query around. For instance, Katherine Harding and Keith Harris each have two results: Medford Outlet Center, Medford Filtering and Sorting with EntityCollections Although you can easily use related data in projections or for filtering, sorting, and other operations, it is important to keep in mind that when the related data is in a collection, you need to leverage operations that can be performed on a set of data.
You may not want the entire collection of addresses, but rather some aggregated information about that collection. Using an aggregate method with a lambda in LINQ from c in context. If you forget to do this, both VB and C will give a compiler error explaining the problem. Therefore, they work very naturally with the LINQ query methods.
A LINQ method syntax query using an aggregate context. First it uses a lambda expression to specify what values should be projected: Once the variable, c, has been declared, the function projects an anonymous type consisting of LastName as the first property and MaxCode as the second. MaxCode is defined by using the Max aggregate on the Addresses collection of the contact. Joins and Nested Queries Although associations in the EDM minimize the need for joins in queries, sometimes a relationship may exist but there is no association to represent the relationship.
In these and other cases, you can use nested queries or joins to bring the data together. Should You Even Use Joins? Navigation properties in combination with nesting sub-queries should be used instead.
These latter constructs represent task requirements much more closely than JOIN does. It also enables joining multiple collections separated by commas. Note You could, of course, add the association to the model in this case, but then there would be no lesson here, would there? Contacts join oa in context.
Any contacts with no match in the vOfficeAddresses will not be returned. When you write a query, anywhere a value is expected you can use another query in its place, as long as that query returns an acceptable type.
You can use a nested query in place of an expression or a collection, as you will see in the following examples. The query uses a nested query highlighted combined with the FirstOrDefault method in place of a projected value to return results from vOfficeAddresses. The first should be familiar: The second twist is that the subquery returns an IQueryable of String, not just a string, which is why the FirstOrDefault method is appended to the query.
Using a nested LINQ query as the collection to be queried You can also use the nested query in place of the collection being queried. The nested query merely returns another collection to be queried. Rather than querying all vOfficeAddresses, you could create a subquery that returns only vOfficeAddresses in Ontario and then query against that.
4. Exploring LINQ to Entities in Greater Depth - Programming Entity Framework, 2nd Edition [Book]
The technique can be useful when you are attempting to express queries that are much more complex. You can benefit from using nested queries to help with complicated queries by separating the nested query from the main query. The second query is complex enough, using another nested query to join vOfficeAddresses back to Contact. Breaking up the query makes the code much more readable. When the query is executed, the Entity Framework will create a single query from the combined expressions.
Warning An Order operator in a subquery will be ignored. The main query controls ordering. You can use grouping in connection with aggregates or to shape data. The results of the grouping can use automatic naming, and in other cases can be explicitly named.
C has an optional INTO clause. Contacts Group By c. Title Into Group C from c in context. Contacts group c by c. Title into mygroup select mygroup The result of this query is an IQueryable of an Entity Framework class called Grouping; more specifically, System.
Default C grouping VB allows you to specify the property name rather than use the default. In VB, the Group property is available to access the group. You can rename this as well. Chain Chain has built in support through a concept known as audit rules.
Audit rules allow you to specify overrides based on a column name. Out of the box, it includes date-based rules and rules that copy a property from a user object into a column. InsertOrUpdate ; As mentioned above, you are going to need a context aware repository for this to work.
In the constructor below you can see how the context is passed to an immutable data source, creating a new data source with the necessary information. Entity Framework To globally apply audit columns in Entity Framework, you need to leverage the ObjectStateManager and create a specialized interface.
The interface, or base class if you prefer, will look something like this: Next you need to override the Save method of your DataContext class as follows.
Entity as IAuditableEntity; if addedEntity! Entity as IAuditableEntity; if modifiedEntity! This is where most of the useful metadata about transactions in progress can be found. Finally, you need to modify the constructor of your data context and possibly repository to accept a user object. While this looks like a lot of code, it only needs to be done once per EF data context. And as with the previous example, the actual creation of the data context and repository can be performed by your DI framework.
History Table Tracking changes to records is often required due to local laws and regulations.70 Long Distance Relationship Quotes
Other times it is desirable simply to make diagnostics easier. Our general recommendation is to simply allow the database to do this. Some databases have this capability built-in, which is often referred to as a temporal table. Others can emulate it using triggers. In either case, the application is unaware of the additional logging, which makes the technique far less error prone.
If for some reason you cannot use a temporal table or trigger, then the repository needs to explicitly write to the history table. Regardless of where you put the code that maintains the history table, there are two basic conventions that you can follow.
Consistency is really important here, as it would be quite confusing to have one convention for some tables and the other convention for the rest. In this convention you copy the old record from live table to the history table prior to performing the update or delete operation.
This means the history table never contains the current record. Alternately you can update the live table first, then copy that row to the history table. This has the advantage of having a complete picture in the history table, eliminating the aforementioned join.
The downside is it takes more space due to the duplicated data. If hard deletes are desired, then they should only be performed following a soft delete. Soft Deletes One of the advantages of using a repository is you can switch from hard deletes to soft deletes without the rest of the application realizing it.
A soft delete removes the record as far as the application is concerned, but allows it to remain in the database for auditing purposes.