EntityFramework Core database first approach pluralizing table names

Question

We have existing database with pluralized table names. For Example Documents. I am trying to use new EF Core and Asp.Net Core with database first approach based on this article here

I run the following command to create models from the existing database

Scaffold-DbContext "Server=(local);Database=MyDatabase;Trusted_Connection=True;"Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

However when I run scaffolding command it creates models with plural names. For example Documents table converted to model name Documents.

How do I change this so it can use singular naming convention for model? (I cannot alter table names in database)

Note that I have read few post on SO related to same issue but they mostly concerned with code first approach. I am using database first approach.

Answer 1

The EF Core tools do not currently include options to customise the output of reverse engineering an existing database in the way that you describe. Currently, your only realistic option is to modify the generated code.

Answer 2

In Entity Framework Core v2 they introduced a pluralizer hook. Where you can pluralize or singularize your objects yourself.

You can do it by adding this to your project:

public class MyDesignTimeServices : IDesignTimeServices
{
    public void ConfigureDesignTimeServices(IServiceCollection services)
    {
        services.AddSingleton<IPluralizer, MyPluralizer>();
    }
}

public class MyPluralizer : IPluralizer
{
    public string Pluralize(string name)
    {
        return Inflector.Inflector.Pluralize(name) ?? name;
    }

    public string Singularize(string name)
    {
        return Inflector.Inflector.Singularize(name) ?? name;
    }
}

More info: What's new in EF core 2

You can use this class as your Inflector:

using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace DMP.Generator
{
    public static class Inflector
    {
        #region Default Rules

        static Inflector()
        {
            AddPlural("$", "s");
            AddPlural("s$", "s");
            AddPlural("(ax|test)is$", "$1es");
            AddPlural("(octop|vir|alumn|fung)us$", "$1i");
            AddPlural("(alias|status)$", "$1es");
            AddPlural("(bu)s$", "$1ses");
            AddPlural("(buffal|tomat|volcan)o$", "$1oes");
            AddPlural("([ti])um$", "$1a");
            AddPlural("sis$", "ses");
            AddPlural("(?:([^f])fe|([lr])f)$", "$1$2ves");
            AddPlural("(hive)$", "$1s");
            AddPlural("([^aeiouy]|qu)y$", "$1ies");
            AddPlural("(x|ch|ss|sh)$", "$1es");
            AddPlural("(matr|vert|ind)ix|ex$", "$1ices");
            AddPlural("([m|l])ouse$", "$1ice");
            AddPlural("^(ox)$", "$1en");
            AddPlural("(quiz)$", "$1zes");

            AddSingular("s$", "");
            AddSingular("(n)ews$", "$1ews");
            AddSingular("([ti])a$", "$1um");
            AddSingular("((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$", "$1$2sis");
            AddSingular("(^analy)ses$", "$1sis");
            AddSingular("([^f])ves$", "$1fe");
            AddSingular("(hive)s$", "$1");
            AddSingular("(tive)s$", "$1");
            AddSingular("([lr])ves$", "$1f");
            AddSingular("([^aeiouy]|qu)ies$", "$1y");
            AddSingular("(s)eries$", "$1eries");
            AddSingular("(m)ovies$", "$1ovie");
            AddSingular("(x|ch|ss|sh)es$", "$1");
            AddSingular("([m|l])ice$", "$1ouse");
            AddSingular("(bus)es$", "$1");
            AddSingular("(o)es$", "$1");
            AddSingular("(shoe)s$", "$1");
            AddSingular("(cris|ax|test)es$", "$1is");
            AddSingular("(octop|vir|alumn|fung)i$", "$1us");
            AddSingular("(alias|status)$", "$1");
            AddSingular("(alias|status)es$", "$1");
            AddSingular("^(ox)en", "$1");
            AddSingular("(vert|ind)ices$", "$1ex");
            AddSingular("(matr)ices$", "$1ix");
            AddSingular("(quiz)zes$", "$1");

            AddIrregular("person", "people");
            AddIrregular("man", "men");
            AddIrregular("child", "children");
            AddIrregular("sex", "sexes");
            AddIrregular("move", "moves");
            AddIrregular("goose", "geese");
            AddIrregular("alumna", "alumnae");

            AddUncountable("equipment");
            AddUncountable("information");
            AddUncountable("rice");
            AddUncountable("money");
            AddUncountable("species");
            AddUncountable("series");
            AddUncountable("fish");
            AddUncountable("sheep");
            AddUncountable("deer");
            AddUncountable("aircraft");
        }

        #endregion

        private class Rule
        {
            private readonly Regex _regex;
            private readonly string _replacement;

            public Rule(string pattern, string replacement)
            {
                _regex = new Regex(pattern, RegexOptions.IgnoreCase);
                _replacement = replacement;
            }

            public string Apply(string word)
            {
                if (!_regex.IsMatch(word))
                {
                    return null;
                }

                return _regex.Replace(word, _replacement);
            }
        }

        private static void AddIrregular(string singular, string plural)
        {
            AddPlural("(" + singular[0] + ")" + singular.Substring(1) + "$", "$1" + plural.Substring(1));
            AddSingular("(" + plural[0] + ")" + plural.Substring(1) + "$", "$1" + singular.Substring(1));
        }

        private static void AddUncountable(string word)
        {
            _uncountables.Add(word.ToLower());
        }

        private static void AddPlural(string rule, string replacement)
        {
            _plurals.Add(new Rule(rule, replacement));
        }

        private static void AddSingular(string rule, string replacement)
        {
            _singulars.Add(new Rule(rule, replacement));
        }

        private static readonly List<Rule> _plurals = new List<Rule>();
        private static readonly List<Rule> _singulars = new List<Rule>();
        private static readonly List<string> _uncountables = new List<string>();

        public static string Pluralize(this string word)
        {
            return ApplyRules(_plurals, word);
        }

        public static string Singularize(this string word)
        {
            return ApplyRules(_singulars, word);
        }

#if NET45 || NETFX_CORE
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
#endif
        private static string ApplyRules(List<Rule> rules, string word)
        {
            string result = word;

            if (!_uncountables.Contains(word.ToLower()))
            {
                for (int i = rules.Count - 1; i >= 0; i--)
                {
                    if ((result = rules[i].Apply(word)) != null)
                    {
                        break;
                    }
                }
            }

            return result;
        }

        public static string Titleize(this string word)
        {
            return Regex.Replace(Humanize(Underscore(word)), @"\b([a-z])",
                                 delegate (Match match)
                                 {
                                     return match.Captures[0].Value.ToUpper();
                                 });
        }

        public static string Humanize(this string lowercaseAndUnderscoredWord)
        {
            return Capitalize(Regex.Replace(lowercaseAndUnderscoredWord, @"_", " "));
        }

        public static string Pascalize(this string lowercaseAndUnderscoredWord)
        {
            return Regex.Replace(lowercaseAndUnderscoredWord, "(?:^|_)(.)",
                                 delegate (Match match)
                                 {
                                     return match.Groups[1].Value.ToUpper();
                                 });
        }

        public static string Camelize(this string lowercaseAndUnderscoredWord)
        {
            return Uncapitalize(Pascalize(lowercaseAndUnderscoredWord));
        }

        public static string Underscore(this string pascalCasedWord)
        {
            return Regex.Replace(
                Regex.Replace(
                    Regex.Replace(pascalCasedWord, @"([A-Z]+)([A-Z][a-z])", "$1_$2"), @"([a-z\d])([A-Z])",
                    "$1_$2"), @"[-\s]", "_").ToLower();
        }

        public static string Capitalize(this string word)
        {
            return word.Substring(0, 1).ToUpper() + word.Substring(1).ToLower();
        }

        public static string Uncapitalize(this string word)
        {
            return word.Substring(0, 1).ToLower() + word.Substring(1);
        }

        public static string Ordinalize(this string numberString)
        {
            return Ordanize(int.Parse(numberString), numberString);
        }

        public static string Ordinalize(this int number)
        {
            return Ordanize(number, number.ToString());
        }

#if NET45 || NETFX_CORE
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
#endif
        private static string Ordanize(int number, string numberString)
        {
            int nMod100 = number % 100;

            if (nMod100 >= 11 && nMod100 <= 13)
            {
                return numberString + "th";
            }

            switch (number % 10)
            {
                case 1:
                    return numberString + "st";
                case 2:
                    return numberString + "nd";
                case 3:
                    return numberString + "rd";
                default:
                    return numberString + "th";
            }
        }


        public static string Dasherize(this string underscoredWord)
        {
            return underscoredWord.Replace('_', '-');
        }
    }
}

The inflector class can be found here

For scaffolding I use the dotnet ef command.

The following NuGet packages are included in my project:

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="2.0.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.0.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="2.0.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.1" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.1" />
  </ItemGroup>
  <ItemGroup>
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.1" />
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.1" />
  </ItemGroup>

Answer 3

You can use Bricelam.EntityFrameworkCore.Pluralizer. To use the package, simply install it. The pluralizer will be used when reverse engineering a model from an existing database.

// Tools > NuGet Package manager > Package Manager Console:
PM> Install-Package Bricelam.EntityFrameworkCore.Pluralizer

Then run your Scaffold-DbContext ... commands. Thats it!

Scaffold-DbContext "ConnectionStr..." Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

Answer 4

Reverse engineering does not currently singularize (is that a word?) table names for entity types, or pluralize them for navigation properties. This is issue #3060. Until then you'll have to manually change them to what you want after generating the code.