Mapping DB values to Enum

Question

I created a new Enum class from db table Role which has RoleId and RoleType.

public enum UserType
{
    Student = 1,
    Teacher = 4
    Admin = 5 
}

Here 1,4,5 are RoleId(Primary Key) from db. What i did is i looked manually for the db primary key value for each role and mapped that to enum.

The demerit here is every time i need to update the enum class when db RoleId Changes.

Is there any other standard practice to map db values as enum collections?

Any suggestions will help

what do you meant? `(UserType)some_value`. I am asking for mapping db values to `enum`. How does it helps? — Hary, Feb 25 '13 at 05:06
http://stackoverflow.com/questions/725043/dynamic-enum-in-c-sharp — 4b0, Feb 25 '13 at 05:07
If you're using EF and code-first, you should be able to just use the Enum: http://msdn.microsoft.com/en-us/data/hh859576.aspx See also: http://stackoverflow.com/questions/6344032/enums-with-ef-code-first-standard-method-to-seeding-db-and-then-using — lc., Feb 25 '13 at 05:08

score 3 · Accepted Answer · answered Feb 25 '13 at 06:13

Recently, I've been facing same problem. One of the possible solutions is using T4 template (codegeneration). You can implement some custom logic to select table(s) and description/value columns. Something like this

    //Start write enum file:        
    #>
    namespace <#=enumNameSpace#>
    {
        public enum <#=enumName#>Enum
        {
        <#
          command.CommandText = string.Format("SELECT * FROM {0}",TABLE_NAME_GOES_HERE);
          var columnReader = command.ExecuteReader();
          while (columnReader.Read())
          {#>   
               <#=columnReader[DESCRIPTION_COLUMN_NAME].ToString()#> = <#=columnReader[VALUE_COLUMN_NAME].ToString()#>,
          <#    
          }#>
        }
    }
    <#

You can read more in this great article

Mapping DB values to Enum

1 Answers1