Making a generic web API controller when using multiple tables with similar fields

Question

I have been trying to refactor my code since I found I've been doing a lot of copying and pasting to implement the logic of the web API controllers. Here's how the controllers looked like before refactoring

Controller for EducationalGroups table:

public class EducationalGroupsController : ApiController
 {
 public HttpResponseMessage Get()
 {
 try
 {
 using (SchoolDbContext entities = new SchoolDbContext())
 return Request.CreateResponse(HttpStatusCode.OK,
 entities.EducationGroups.Where(g => !g.Is_Delete).ToList());
 }
 catch (Exception e)
 {
 return Request.CreateErrorResponse(HttpStatusCode.NoContent, e);
 }
 }
 public HttpResponseMessage Post([FromBody] EducationGroup group)
 {
 try
 {
 using (SchoolDbContext entities = new SchoolDbContext())
 {
 group.Create_User = WebApiConfig.CurrUserIdx;
 group.Create_Date = DateTime.Now;
 entities.EducationGroups.Add(group);
 entities.SaveChanges();
 var msg = Request.CreateResponse(HttpStatusCode.Created, group);
 msg.Headers.Location = new Uri(Request.RequestUri, group.Id.ToString());
 return msg;
 }
 }
 catch (Exception e)
 {
 return Request.CreateErrorResponse(HttpStatusCode.BadRequest, e);
 }
 }
 }

Controller for EducationalStages table:

public class EducationalStagesController : ApiController
 {
 public HttpResponseMessage Get()
 {
 try
 {
 //Notice the only difference here is the *Educational_Stages* object of type DbSet
 using (SchoolDbContext entities = new SchoolDbContext())
 return Request.CreateResponse(HttpStatusCode.OK, 
 entities.Education_Stages.Where(s => !s.Is_Delete).ToList());
 }
 catch (Exception e)
 {
 return Request.CreateErrorResponse(HttpStatusCode.NoContent, e);
 }
 }
 //Same implementation for this method as previous controller 
 //Only with the difference of the type of the parameter
 public HttpResponseMessage Post([FromBody] Education_Stages stage)
 {
 try
 {
 using (SchoolDbContext entities = new SchoolDbContext())
 {
 stage.Create_User = WebApiConfig.CurrUserIdx;
 stage.Create_Date = DateTime.Now;
 entities.Education_Stages.Add(stage);
 entities.SaveChanges();
 var msg = Request.CreateResponse(HttpStatusCode.Created, stage);
 msg.Headers.Location = new Uri(Request.RequestUri, stage.Id.ToString());
 return msg;
 }
 }
 catch (Exception e)
 {
 return Request.CreateErrorResponse(HttpStatusCode.BadRequest, e);
 }
 }
 }

There are like 8 more controllers required for 8 more tables, so you get the idea of how redundant it looks like...

What I've been trying to do is create a base class for the entities that share the same fields as follows:

public abstract class BaseEntity
 {
 public int Id { get; set; }
 [StringLength(50)]
 public string Ar_Name { get; set; }
 [StringLength(10)]
 public string En_Name { get; set; }
 public bool Is_Delete { get; set; }
 public int? Create_User { get; set; }
 public DateTime? Create_Date { get; set; }
 public int? Last_Update_User { get; set; }
 public DateTime? Last_Update_Date { get; set; }
 }

And inherit it in all of the entities sharing the same fields:

public partial class Education_Stages : BaseEntity
 {
 }

And then create a base class for the API controllers to inherit from as follows, and here's where I can't find any more solutions for what I want:

public abstract class BaseApiVerbs<T> : ApiController where T : BaseEntity
 {
 private DbSet<T> dbSet;
 public BaseApiVerbs(DbSet<T> _dbSet)
 {
 dbSet = _dbSet;
 }
 public HttpResponseMessage Get()
 {
 try
 {
 return Request.CreateResponse(HttpStatusCode.OK, 
 dbSet.Where(t => t.Is_Delete == false));
 }
 catch (Exception e)
 {
 return Request.CreateErrorResponse(HttpStatusCode.BadRequest, e);
 }
 }
 public HttpResponseMessage Post([FromBody] T entity)
 {
 // No Idea how to implement the same logic here without using DbContext... 
 }

Furthermore, I don't know how to initialize the controllers' classes and pass the DbSet object accordingly:

public class CityController : BaseApiVerbs<City>
 {
 SchoolDbContext context = new SchoolDbContext();
 public CityController() 
 : base( /* How would I pass the DbSet object here? */ )
 {
 
 }
 }

Is the idea of copying and pasting the code acceptable in this case? If not, how can I accomplish what I've been trying to do for the past two days?

I am a beginner so please don't be harsh in your replies if you found anything smelly in my code, kindly note it for me :)

• Peter Csala: Do I understand correctly that the refactored version is not complete?
• Gert Arnold: A good start would be to go use dependency injection. If this is .net core, a DI framework is readily available.

Answer 1

Honestly, don't try to invent new ways of doing things and instead learn well-documented ways of doing things, like MediatR and CQRS.

Please follow the Microsoft guidelines when naming things: only alphanumeric characters are allowed in property names, class names etc. (exception is the underscore at the start of a private member variable).

Use readable names. Ar_Name and En_Name are meaningless. Create_User and the likes are names of methods, not properties.