Using a string to call a table in Entity Framework - asp.net-mvc

Question

Here's my old code.
public override Task ExecuteAsync(string generator, WebHookHandlerContext context)
{
DatawarehouseEntities db = new DatawarehouseEntities();
// Get JSON from WebHook
JObject data = context.GetDataOrDefault<JObject>();
var tableName = data["Table_Name"].ToString();
var columnNames = db.Database.SqlQuery<string>(String.Format("SELECT name FROM sys.columns WHERE object_id = OBJECT_ID('{0}'); ", tableName)).ToList();
var table = db.GetType().GetProperty(tableName).GetValue(db, null);
var assembly = AppDomain.CurrentDomain.GetAssemblies()
.SingleOrDefault(a => a.GetName().Name == "DSI.Data");
var type = assembly.GetTypes().FirstOrDefault(t => t.Name == tableName);
var dbset = Activator.CreateInstance(type);
//var dbset = db.Set(type);
var jsonParams = data.Properties().Select(x => x.Name).ToList();
var selectedColumnNames = columnNames.Intersect(jsonParams);
foreach (var columnName in selectedColumnNames)
{
var property = dbset.GetType().GetProperties().FirstOrDefault(x => x.Name == columnName);
property.SetValue(dbset, data[columnName].ToString(), null);
}
db.Set(type).Add(dbset);
db.SaveChanges();
return Task.FromResult(true);
}
Here's what I try to post http://localhost:port/api/webhooks/incoming/genericjson?code=secret&Table_Name=Table_Name. The type always comes back null. How can I select a table using the string that I pass in?

Answer 1

To make this easier, faster and less error-prone enumerate your entity types and add them to a lookup. EG
public static Dictionary<string, Type> EntityTypesByName { get; } = new Dictionary<string, Type>();
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
foreach (var et in modelBuilder.Model.GetEntityTypes())
{
EntityTypesByName.Add(et.Name, et.ClrType);
}
}

Answer 2

This is what finally worked for me.
public override Task ExecuteAsync(string generator, WebHookHandlerContext context)
{
DatawarehouseEntities db = new DatawarehouseEntities();
// Get JSON from WebHook
JObject data = context.GetDataOrDefault<JObject>();
var tableName = data["Table_Name"].ToString();
var columnNames = db.Database.SqlQuery<string>(String.Format("SELECT name FROM sys.columns WHERE object_id = OBJECT_ID('{0}'); ", tableName)).ToList();
var table = db.GetType().GetProperty(tableName).GetValue(db, null);
var assembly = AppDomain.CurrentDomain.GetAssemblies()
.SingleOrDefault(a => a.GetName().Name == "DSI.Data");
var type = assembly.GetTypes().FirstOrDefault(t => t.Name == tableName);
var dbset = Activator.CreateInstance(type);
var jsonParams = data.Properties().Select(x => x.Name).ToList();
var selectedColumnNames = columnNames.Intersect(jsonParams);
foreach (var columnName in selectedColumnNames)
{
var property = dbset.GetType().GetProperties().FirstOrDefault(x => x.Name == columnName);
property.SetValue(dbset, data[columnName].ToString(), null);
}
db.Set(type).Add(dbset);
db.SaveChanges();
return Task.FromResult(true);
}