How to get Column name and corresponding Database Type from DbContext in Entity Framework Core
Update (EF Core 3.x): Starting with EF Core 3.0, the metadata API has changed again - Relational()
extensions have been removed, and properties have been replaced with Get
and Set
extension methods, so now the code looks like this:
var entityType = dbContext.Model.FindEntityType(clrEntityType);
// Table info
var tableName = entityType.GetTableName();
var tableSchema = entityType.GetSchema();
// Column info
foreach (var property in entityType.GetProperties())
{
var columnName = property.GetColumnName();
var columnType = property.GetColumnType();
};
Update (EF Core 2.x): Starting with EF Core 2.0, the things have changed, so the original answer does not apply anymore. Now EF Core builds separate model for each database type, so the code is much simpler and uses directly the Relational()
extensions:
var entityType = dbContext.Model.FindEntityType(clrEntityType);
// Table info
var tableName = entityType.Relational().TableName;
var tableSchema = entityType.Relational().Schema;
// Column info
foreach (var property in entityType.GetProperties())
{
var columnName = property.Relational().ColumnName;
var columnType = property.Relational().ColumnType;
};
Original answer (EF Core 1.x):
Getting the access to the associated metadata is much easier in EF Core compared to EF - you start from DbContext.Model
property to get IModel
, use GetEntityTypes
or FindEntityType
to get IEntityType
, then GetProperties
or FindProperty
to get IProperty
etc.
However the problem is that EF Core allows you to use different setting fro different target database. In order to get the attributes corresponding to the current database used by the context, you need to get access to the IRelationalDatabaseProviderServices
and use AnnotationProvider
and TypeMapper
properties to get the information needed.
Here is an example:
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Internal;
using Microsoft.EntityFrameworkCore.Storage;
public class DbColumnInfo
{
public string Name;
public string Type;
}
public static class RelationalDbHelpers
{
public static IEnumerable<DbColumnInfo> GetDbColums(this DbContext dbContext, Type clrEntityType)
{
var dbServices = dbContext.GetService<IDbContextServices>();
var relationalDbServices = dbServices.DatabaseProviderServices as IRelationalDatabaseProviderServices;
var annotationProvider = relationalDbServices.AnnotationProvider;
var typeMapper = relationalDbServices.TypeMapper;
var entityType = dbContext.Model.FindEntityType(clrEntityType);
// Not needed here, just an example
var tableMap = annotationProvider.For(entityType);
var tableName = tableMap.TableName;
var tableSchema = tableMap.Schema;
return from property in entityType.GetProperties()
let columnMap = annotationProvider.For(property)
let columnTypeMap = typeMapper.FindMapping(property)
select new DbColumnInfo
{
Name = columnMap.ColumnName,
Type = columnTypeMap.StoreType
};
}
}