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jsakamoto
jsakamoto

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How to get the actual table name from DbSet in EntityFramework Core 2.0.

#dotnet #netcore #entityframework #efcore20

The way of getting actual table name

For example, if you have DbContext object like this (C#):

public class MyDbContext : DbContext { public DbSet<FooBar> FooBars { get; set; } } ... var dbContext = new MyDbContext();
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You can obtain the actual table name of the DbSet property from the DbContext instance with the following code.

// DbContext knows everything about the model. var model = dbContext.Model; // Get all the entity types information contained in the DbContext class, ... var entityTypes = model.GetEntityTypes(); // ... and get one by entity type information of "FooBars" DbSet property. var entityTypeOfFooBar = entityTypes.First(t => t.ClrType == typeof(FooBar)); // The entity type information has the actual table name as an annotation! var tableNameAnnotation = entityTypeOfFooBar.GetAnnotation("Relational:TableName"); var tableNameOfFooBarSet = tableNameAnnotation.Value.ToString();
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Package as an extension method

By the way, we can get a DbContext from a DbSet.

See also: "How to get a DbContext from a DbSet in EntityFramework Core 2.0."

Therefore, you can package the above code as an extension method like this C# code:

using System; using System.Linq; using Microsoft.EntityFrameworkCore; using Microsoft.EntityFrameworkCore.Infrastructure; // Prerequire: You have to install DbContextGetter class in this project. // https://dev.to/j_sakamoto/how-to-get-a-dbcontext-from-a-dbset-in-entityframework-core-c6m public static class TableNameOfDbSetGetter { public static string GetTableName<T>(this DbSet<T> dbSet) where T: class { var dbContext = dbSet.GetDbContext(); var model = dbContext.Model; var entityTypes = model.GetEntityTypes(); var entityType = entityTypes.First(t => t.ClrType == typeof(T)); var tableNameAnnotation = entityType.GetAnnotation("Relational:TableName"); var tableName = tableNameAnnotation.Value.ToString(); return tableName; } } // How to use: //  // class MyDbContext : DbContext { // public DbSet<FooBar> FooBars { get; set; } // } // ... // var myContext = new MyDbContext(); // var tableName = myContext.FooBars.GetTableName(); // ~~~~~~~~~~~~~~ // tableName; // -> "FooBars"
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This code works fine even if the entity class is decorated with [TableAttribute("TableName")].

Happy coding :)

Top comments (1)

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bastijan profile image
Sasa Jovanovic •

Actually, you already know a table name :)

// var tableName = myContext.FooBars.GetTableName();
// ~~~~~~~~~~~~~~
// tableName; // -> "FooBars"