how to map enum with database id

This question already has an answer here:

Cast int to enum in C# 21 answers

Enum ToString with user friendly strings 19 answers

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你并不需要任何特别的东西，你可以将你从数据库中得到的整数转换为你的枚举：

int valueFromDB = 4;
Days enumValue = (Days)valueFromDB;

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I would not suggest this approach. You need a look-up table for days. For instance

create table Days(
 DaysID INT PRIMARY KEY,
 Name VARCHAR(20))

All other tables will have a foreign key column of DaysID. The reason why I suggest against your approach is because your limiting yourself to hard coded values that may change.

If needed you can load your Days table into a List<KeyValuePair<int, string>> . If you leave as is, no one looking at the database will know ways DaysID 1, 2, 3, 4, etc represents.

I hope this helps.

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Use below extension method to wordify your enum

/// <summary>
/// Get the whilespace separated values of an enum
/// </summary>
/// <param name="en"></param>
/// <returns></returns>
public static string ToEnumWordify(this Enum en)
{
    Type type = en.GetType();
    MemberInfo[] memInfo = type.GetMember(en.ToString());
    string pascalCaseString = memInfo[0].Name;
    Regex r = new Regex("(?<=[a-z])(?<x>[A-Z])|(?<=.)(?<x>[A-Z])(?=[a-z])");
    return r.Replace(pascalCaseString, " ${x}");
}

Or you can supply Description to enum get it using below

public enum Manufacturer
{
    [DescriptionAttribute("I did")]
    Idid = 1,
    [DescriptionAttribute("Another company or person")]
    AnotherCompanyOrPerson = 2
}

/// <summary>
/// Get the enum description value
/// </summary>
/// <param name="en"></param>
/// <returns></returns>
public static string ToEnumDescription(this Enum en) //ext method
{
    Type type = en.GetType();
    MemberInfo[] memInfo = type.GetMember(en.ToString());
    if (memInfo != null && memInfo.Length > 0)
    {
        object[] attrs = memInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);
        if (attrs != null && attrs.Length > 0)
            return ((DescriptionAttribute)attrs[0]).Description;
    }
    return en.ToString();
}

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