What is database context?

It is a bridge between your domain or entity classes and the database. DbContext is the primary class that is responsible for interacting with the database. It is responsible for the following activities: Querying: Converts LINQ-to-Entities queries to SQL query and sends them to the database.

What is DB context class?

A DbContext instance represents a combination of the Unit Of Work and Repository patterns such that it can be used to query from a database and group together changes that will then be written back to the store as a unit. DbContext is conceptually similar to ObjectContext.

Which command to use for changing the context of the database to different database?

Try using sp_MSforeachdb (be aware, it is undocumented). Put either of these in your loop against the db names and this should solve your problem. Put either of these in your loop against the db names and this should solve your problem.” You could use xp_execresultset to set database context, e.g.

How do I find current database in SQL?

  1. DB_NAME ( [ database_id ] )
  2. SELECT DB_NAME() AS [Current Database]; GO.
  3. USE master; GO SELECT DB_NAME(3) AS [Database Name]; GO.
  4. SELECT DB_NAME() AS [Current Database];
  5. SELECT DB_NAME(database_id) AS [Database], database_id FROM sys.databases;

How do you create a database context class?

To use code-first for an existing database, right click on your project in Visual Studio -> Add -> New Item.. Select ADO.NET Entity Data Model in the Add New Item dialog box and specify the model name (this will be a context class name) and click on Add. This will open the Entity Data Model wizard as shown below.

What is database context in MVC?

The context class is a most important class while working with EF 6 or EF Core. It represent a session with the underlying database using which you can perform CRUD (Create, Read, Update, Delete) operations. The context class is used to query or save data to the database.

How do I find database details in SQL Server?

Using SQL Server Management Studio

  1. In Object Explorer, connect to an instance of the SQL Server Database Engine, and then expand that instance.
  2. Expand Databases, right-click the database to view, and then click Properties.
  3. In the Database Properties dialog box, select a page to view the corresponding information.

How do I find the current database in MySQL?

If you just need the current database name, you can use MySQL’s SELECT DATABASE() command: php function mysql_current_db() { $r = mysql_query(“SELECT DATABASE()”) or die(mysql_error()); return mysql_result($r,0); }?> Highly active question.

What all operations could be done using DB context instance?

You can use a DbContext associated to a model to:

  • Write and execute queries.
  • Materialize query results as entity objects.
  • Track changes that are made to those objects.
  • Persist object changes back on the database.
  • Bind objects in memory to UI controls.

How does context work in SQL Server?

By default, the context manages connections to the database. The context opens and closes connections as needed. For example, the context opens a connection to execute a query, and then closes the connection when all the result sets have been processed.

What is session_context() in SQL Server 2016?

SQL Server 2016 introduced a new built-in-function SESSION_CONTEXT () as improvement over the existing CONTEXT_INFO function. It uses key-value pairs for storing the session data. It works with the SQL Azure database as well. We set these key-value pairs using the stored procedure sp_set_session_context.

How do I get the context info of a session?

This function returns the context_info value either set for the current session or batch, or derived through use of the SET CONTEXT_INFO statement. The context_info value. If context_info was not set: In SQL Server returns NULL. In SQL Database returns a unique session-specific GUID.

How do I use a dbcontext in a model?

You can use a DbContext associated to a model to: This page gives some guidance on how to manage the context class. The recommended way to work with context is to define a class that derives from DbContext and exposes DbSet properties that represent collections of the specified entities in the context.