Add description column to lookup table

contribution from PR #35 - Svein Helge <[email protected]>
fixed-up, squashed, rewritten by Tim Abell

still stuff that needs fixing up in this commit
- see pull request for details

EfEnumToLookup/LookupGenerator/EnumParser.cs

@@ -57,6 +57,7 @@ public IEnumerable<LookupValue> GetLookupValues(Type lookup)
 				{
 					Id = (int)numericValue,
 					Name = EnumName(value),
+					Description = EnumDescriptionValue(value)
 				});
 			}
 			return values;
@@ -70,12 +71,6 @@ public IEnumerable<LookupValue> GetLookupValues(Type lookup)
 		/// </summary>
 		private string EnumName(Enum value)
 		{
-			var description = EnumDescriptionValue(value);
-			if (description != null)
-			{
-				return description;
-			}
-
 			var name = value.ToString();
 
 			if (SplitWords)

EfEnumToLookup/LookupGenerator/EnumToLookup.cs

@@ -29,6 +29,7 @@ public EnumToLookup()
 		{
 			// set default behaviour, can be overridden by setting properties on object before calling Apply()
 			NameFieldLength = 255;
+			DescriptionFieldLength = 255;
 			TableNamePrefix = "Enum_";
 			_enumParser = new EnumParser { SplitWords = true };
 			UseTransaction = true;
@@ -50,6 +51,12 @@ public bool SplitWords
 		/// </summary>
 		public int NameFieldLength { get; set; }
 
+		/// <summary>
+		/// The size of the Description field that will be added to the generated lookup tables.
+		/// Adjust to suit your data if required, defaults to 255.
+		/// </summary>
+		public int DescriptionFieldLength { get; set; }
+
 		/// <summary>
 		/// Prefix to add to all the generated tables to separate help group them together
 		/// and make them stand out as different from other tables.
@@ -114,6 +121,7 @@ private IDbHandler GetDbHandler()
 			IDbHandler dbHandler = new SqlServerHandler
 			{
 				NameFieldLength = NameFieldLength,
+				DescriptionFieldLength = DescriptionFieldLength,
 				TableNamePrefix = TableNamePrefix,
 				TableNameSuffix = TableNameSuffix,
 				UseTransaction = UseTransaction,

EfEnumToLookup/LookupGenerator/IDbHandler.cs

@@ -12,6 +12,12 @@ internal interface IDbHandler
 		/// </summary>
 		int NameFieldLength { get; set; }
 
+		/// <summary>
+		/// The size of the Description field that will be added to the generated lookup tables.
+		/// Adjust to suit your data if required.
+		/// </summary>
+		int DescriptionFieldLength { get; set; }
+
 		/// <summary>
 		/// Prefix to add to all the generated tables to separate help group them together
 		/// and make them stand out as different from other tables.

EfEnumToLookup/LookupGenerator/LookupValue.cs

@@ -4,5 +4,6 @@ internal class LookupValue
 	{
 		public int Id { get; set; }
 		public string Name { get; set; }
+		public string Description { get; set; }
 	}
 }

EfEnumToLookup/LookupGenerator/SqlServerHandler.cs

@@ -13,6 +13,12 @@ class SqlServerHandler : IDbHandler
 		/// </summary>
 		public int NameFieldLength { get; set; }
 
+		/// <summary>
+		/// The size of the Description field that will be added to the generated lookup tables.
+		/// Adjust to suit your data if required, defaults to 255.
+		/// </summary>
+		public int DescriptionFieldLength { get; set; }
+
 		/// <summary>
 		/// Prefix to add to all the generated tables to separate help group them together
 		/// and make them stand out as different from other tables.
@@ -82,12 +88,12 @@ private string CreateTables(IEnumerable<LookupData> enums)
 				sql.AppendFormat(
 					@"IF OBJECT_ID('{0}', 'U') IS NULL
 begin
-	CREATE TABLE [{0}] (Id {2} CONSTRAINT PK_{0} PRIMARY KEY, Name nvarchar({1}));
+	CREATE TABLE [{0}] (Id {2} CONSTRAINT PK_{0} PRIMARY KEY, Name nvarchar({1}), Description nvarchar({3}));
 	exec sys.sp_addextendedproperty @name=N'MS_Description', @level0type=N'SCHEMA', @level0name=N'dbo', @level1type=N'TABLE',
 		@level1name=N'{0}', @value=N'Automatically generated. Contents will be overwritten on app startup. Table & contents generated by https://github.com/timabell/ef-enum-to-lookup';
 end
 ",
-					TableName(lookup.Name), NameFieldLength, NumericSqlType(lookup.NumericType));
+					TableName(lookup.Name), NameFieldLength, NumericSqlType(lookup.NumericType), DescriptionFieldLength);
 			}
 			return sql.ToString();
 		}
@@ -110,7 +116,7 @@ private string AddForeignKeys(IEnumerable<EnumReference> refs)
 		private string PopulateLookups(IEnumerable<LookupData> lookupData)
 		{
 			var sql = new StringBuilder();
-			sql.AppendLine(string.Format("CREATE TABLE #lookups (Id int, Name nvarchar({0}) COLLATE database_default);", NameFieldLength));
+			sql.AppendLine(string.Format("CREATE TABLE #lookups (Id int, Name nvarchar({0}), Description nvarchar({1}) COLLATE database_default);", NameFieldLength, DescriptionFieldLength));
 			foreach (var lookup in lookupData)
 			{
 				sql.AppendLine(PopulateLookup(lookup));
@@ -124,7 +130,7 @@ private string PopulateLookup(LookupData lookup)
 			var sql = new StringBuilder();
 			foreach (var value in lookup.Values)
 			{
-				sql.AppendFormat("INSERT INTO #lookups (Id, Name) VALUES ({0}, N'{1}');\r\n", value.Id, SanitizeSqlString(value.Name));
+				sql.AppendFormat("INSERT INTO #lookups (Id, Name, Description) VALUES ({0}, N'{1}', N'{2}');\r\n", value.Id, SanitizeSqlString(value.Name), SanitizeSqlString(value.Description));
 			}
 
 			sql.AppendLine(string.Format(@"
@@ -133,8 +139,8 @@ MERGE INTO [{0}] dst
 	WHEN MATCHED AND src.Name <> dst.Name collate Latin1_General_BIN2 THEN
 		UPDATE SET Name = src.Name
 	WHEN NOT MATCHED THEN
-		INSERT (Id, Name)
-		VALUES (src.Id, src.Name)
+		INSERT (Id, Name, Description)
+		VALUES (src.Id, src.Name, src.Description)
 	WHEN NOT MATCHED BY SOURCE THEN
 		DELETE
 ;"
@@ -146,7 +152,7 @@ WHEN NOT MATCHED BY SOURCE THEN
 
 		private static string SanitizeSqlString(string value)
 		{
-			return value.Replace("'", "''");
+			return value == null ? null : value.Replace("'", "''");
 		}
 
 		private string TableName(string enumName)

EfEnumToLookupTests/Tests/EnumParserTests.cs

@@ -48,7 +48,7 @@ public void ReadsByteEnum()
 
 
 		[Test]
-		public void ReadsDecoratedName()
+		public void ReadsDecoratedDescription()
 		{
 			// arrange
 			var parser = new EnumParser { SplitWords = true };
@@ -57,7 +57,7 @@ public void ReadsDecoratedName()
 			var result = parser.GetLookupValues(typeof(DecoratedEnum));
 
 			// assert
-			Assert.AreEqual("Wide boy", result.Single().Name);
+			Assert.AreEqual("Wide boy", result.Single().Description);
 		}
 
 		private enum BareEnum

ExampleUsage/EnumExample.cs

@@ -1,5 +1,8 @@
 using System;
+using System.Data;
 using System.Data.Entity;
+using System.Data.SqlClient;
+using System.Linq;
 using EfEnumToLookup.LookupGenerator;
 using NUnit.Framework;
 
@@ -56,6 +59,44 @@ public void ExampleOfGeneratingSql()
 				context.Database.ExecuteSqlCommand(migrationSql);
 			}
 		}
+
+		[Test]
+		public void CheckIfDescriptionColumnsExists()
+		{
+			using (var context = new MyDbContext())
+			{
+				var enumToLookup = new EnumToLookup();
+
+				// if you need to get at the raw sql to run a migration separately then use:
+				var migrationSql = enumToLookup.GenerateMigrationSql(context);
+				// you'd probably want to write this to a file and then add it to source control, but for
+				// the purpose of demonstration we'll write it to the console instead:
+				Console.Out.WriteLine(migrationSql);
+
+				// at some point you'd then run the sql (probably not like this, but this serves as a test that it's working)
+				context.Database.ExecuteSqlCommand(migrationSql);
+
+				var descriptions = context.Database.SqlQuery<LookupRow>("Select Id, Name, Description From Enum_Size");
+
+				var descriptionList = descriptions.ToList();
+
+				Assert.AreEqual(4, descriptionList.Count);
+
+				Assert.AreEqual(string.Empty, descriptionList.Single(x => x.Id == (int)Size.Small).Description);
+				Assert.AreEqual("It's average", descriptionList.Single(x => x.Id == (int)Size.Medium).Description);
+				Assert.AreEqual(string.Empty, descriptionList.Single(x => x.Id == (int)Size.ReallyVeryBig).Description);
+				Assert.AreEqual("Huge you know?", descriptionList.Single(x => x.Id == (int)Size.Huge).Description);
+
+				var shapes = context.Database.SqlQuery<LookupRow>("Select Id, Name, Description From Enum_Shape");
+
+				var shapeList = shapes.ToList();
+
+				Assert.AreEqual(2, shapeList.Count);
+
+				Assert.AreEqual(string.Empty, shapeList.Single(x => x.Id == (int)Shape.Square).Description);
+				Assert.AreEqual("Round it is!", shapeList.Single(x => x.Id == (int)Shape.Round).Description);
+			}
+		}
 	}
 
 	/// <summary>
@@ -90,7 +131,7 @@ public enum Size
 		ReallyVeryBig,
 
 		// this is only fully qualified because of a name clash with NUnit, you wouldn't normally need to.
-		[System.ComponentModel.Description("Huge you know?")] // give it a different name in the lookup table
+		[System.ComponentModel.Description("Huge you know?")]
 		Huge,
 
 		[RuntimeOnly] // this won't exist in the database, handy to prevent unwanted data creeping in (enforced by foreign key constraint).
@@ -100,6 +141,14 @@ public enum Size
 	public enum Shape
 	{
 		Square,
+		[System.ComponentModel.Description("Round it is!")]
 		Round
 	}
+
+	public class LookupRow
+	{
+		public int Id { get; set; }
+		public string Name { get; set; }
+		public string Description { get; set; }
+	}
 }