In other words if you "inner" join 10 rows from DB1.TABLE1 with 20 rows from DB2.TABLE2, both sets (all 30 rows) must be pulled into memory on your local machine before Linq performs the join and returns the related/intersecting set (20 rows max per example). The context class manages the entity objects during run time, which includes populating objects with data from a database, change tracking, and persisting data to the database. In TSQL, I can reference them with the DB>user>table structure (, ) to pull the data for comparison. These databases do not have the same schema. After referencing all packages, MultipleDbContexts.
A number of nuget packages needs to be referenced. I named the entry project and solution MultipleDbContexts. Join() is misleading, and not appropriate for joining tables in EF. I am often comparing data in tables in different databases. First step is to create a MVC Web API Core project that will later use our DB contexts. Include() notation to join tables together manually, resulting in generally more efficient queries.Include() is used to explicitly join entities in Entity Framework. Note, joins across contexts are performed locally so you must call ToList(), ToArray(), etc to execute the queries using their respective data sources individually before joining. My preference is to disable lazy loading on the context, and use. I named the entry project and solution MultipleDbContexts. How can I relate two objects from different contexts together The example below throws the following exception: System. There are certain techniques to follow when writing queries to make sure they run quickly and effectively.
You can instantiate as many contexts as you like to disparate SQL instances and execute pseudo cross database joins, copy data, etc. Entity Framework Core Query data Complex Query Operators Article 8 minutes to read 6 contributors Feedback In this article Join GroupJoin SelectMany GroupBy Left Join Language Integrated Query (LINQ) contains many complex operators, which combine multiple data sources or does complex processing. First step is to create a MVC Web API Core project that will later use our DB contexts. OctoUPDATED LINQ is a powerful querying tool for.
0 kommentar(er)
