Added table hint for "INDEX(name)"

Author: PawelGerr

Directory.Build.props

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <Copyright>(c) $([System.DateTime]::Now.Year), Pawel Gerr. All rights reserved.</Copyright>
-    <VersionPrefix>4.4.2</VersionPrefix>
+    <VersionPrefix>4.5.0</VersionPrefix>
     <Authors>Pawel Gerr</Authors>    
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageProjectUrl>https://dev.azure.com/pawelgerr/Thinktecture.EntityFrameworkCore</PackageProjectUrl>

src/Thinktecture.EntityFrameworkCore.Relational/EntityFrameworkCore/ITableHint.cs

@@ -1,8 +1,16 @@
+using Microsoft.EntityFrameworkCore.Storage;
+
 namespace Thinktecture.EntityFrameworkCore;
 
 /// <summary>
 /// Represents a table hint.
 /// </summary>
 public interface ITableHint
 {
-}
+   /// <summary>
+   /// Returns a string representing the table hint.
+   /// </summary>
+   /// <param name="sqlGenerationHelper">SQL generation helper.</param>
+   /// <returns>Table hint.</returns>
+   string ToString(ISqlGenerationHelper sqlGenerationHelper);
+}

src/Thinktecture.EntityFrameworkCore.SqlServer/EntityFrameworkCore/Query/ThinktectureSqlServerQuerySqlGenerator.cs

@@ -52,7 +52,7 @@ private void VisitTableWithHints(TableWithHintsExpression tableWithHints)
          if (i != 0)
             Sql.Append(", ");
 
-         Sql.Append(tableWithHints.TableHints[i].ToString()!);
+         Sql.Append(tableWithHints.TableHints[i].ToString(Dependencies.SqlGenerationHelper));
       }
 
       Sql.Append(")");

src/Thinktecture.EntityFrameworkCore.SqlServer/EntityFrameworkCore/SqlServerTableHint.cs

@@ -1,3 +1,5 @@
+using Microsoft.EntityFrameworkCore.Storage;
+
 namespace Thinktecture.EntityFrameworkCore;
 
 /// <summary>
@@ -108,6 +110,14 @@ public static SqlServerTableHint Spatial_Window_Max_Cells(int value)
       return new($"SPATIAL_WINDOW_MAX_CELLS = {value}");
    }
 
+   /// <summary>
+   /// INDEX(name)
+   /// </summary>
+   public static SqlServerTableHint Index(string name)
+   {
+      return new IndexTableHint(name);
+   }
+
    private readonly string _value;
 
    private SqlServerTableHint(string value)
@@ -118,13 +128,7 @@ private SqlServerTableHint(string value)
    /// <inheritdoc />
    public override bool Equals(object? obj)
    {
-      if (ReferenceEquals(null, obj))
-         return false;
-      if (ReferenceEquals(this, obj))
-         return true;
-      if (obj.GetType() != GetType())
-         return false;
-      return Equals((SqlServerTableHint)obj);
+      return ReferenceEquals(this, obj) || (obj is SqlServerTableHint other && Equals(other));
    }
 
    /// <inheritdoc />
@@ -149,4 +153,45 @@ public override string ToString()
    {
       return _value;
    }
+
+   /// <inheritdoc />
+   public virtual string ToString(ISqlGenerationHelper sqlGenerationHelper)
+   {
+      return _value;
+   }
+
+   private sealed class IndexTableHint : SqlServerTableHint, IEquatable<IndexTableHint>
+   {
+      private readonly string _name;
+
+      public IndexTableHint(string name)
+         : base($"INDEX({name})")
+      {
+         _name = name;
+      }
+
+      public override bool Equals(object? obj)
+      {
+         return ReferenceEquals(this, obj) || (obj is IndexTableHint other && Equals(other));
+      }
+
+      public bool Equals(IndexTableHint? other)
+      {
+         if (ReferenceEquals(null, other))
+            return false;
+         if (ReferenceEquals(this, other))
+            return true;
+         return base.Equals(other) && _name == other._name;
+      }
+
+      public override int GetHashCode()
+      {
+         return HashCode.Combine(base.GetHashCode(), _name);
+      }
+
+      public override string ToString(ISqlGenerationHelper sqlGenerationHelper)
+      {
+         return $"INDEX({sqlGenerationHelper.DelimitIdentifier(_name)})";
+      }
+   }
 }

tests/Thinktecture.EntityFrameworkCore.SqlServer.Tests/Extensions/QueryableExtensionsTests/WithTableHints.cs

@@ -26,6 +26,18 @@ public async Task Should_add_table_hints_to_table()
       result.Should().BeEmpty();
    }
 
+   [Fact]
+   public async Task Should_escape_index_name()
+   {
+      var query = ActDbContext.TestEntities.WithTableHints(SqlServerTableHint.Index("IX_TestEntities_Id"));
+
+      query.ToQueryString().Should().Be("SELECT [t].[Id], [t].[ConvertibleClass], [t].[Count], [t].[Name], [t].[ParentId], [t].[PropertyWithBackingField], [t].[RequiredName], [t].[_privateField]" + Environment.NewLine +
+                                        $"FROM {EscapedSchema}.[TestEntities] AS [t] WITH (INDEX([IX_TestEntities_Id]))");
+
+      var result = await query.ToListAsync();
+      result.Should().BeEmpty();
+   }
+
    [Fact]
    public void Should_not_mess_up_table_hints()
    {