Add support for index sort options

src/EFCore.PG/Design/Internal/NpgsqlAnnotationCodeGenerator.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Diagnostics;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore;
@@ -163,6 +163,12 @@ public override MethodCallCodeFragment GenerateFluentApi(IIndex index, IAnnotati
                 return new MethodCallCodeFragment(nameof(NpgsqlIndexBuilderExtensions.ForNpgsqlHasMethod), annotation.Value);
             if (annotation.Name == NpgsqlAnnotationNames.IndexOperators)
                 return new MethodCallCodeFragment(nameof(NpgsqlIndexBuilderExtensions.ForNpgsqlHasOperators), annotation.Value);
+            if (annotation.Name == NpgsqlAnnotationNames.IndexCollation)
+                return new MethodCallCodeFragment(nameof(NpgsqlIndexBuilderExtensions.ForNpgsqlHasCollation), annotation.Value);
+            if (annotation.Name == NpgsqlAnnotationNames.IndexSortOrder)
+                return new MethodCallCodeFragment(nameof(NpgsqlIndexBuilderExtensions.ForNpgsqlHasSortOrder), annotation.Value);
+            if (annotation.Name == NpgsqlAnnotationNames.IndexNullSortOrder)
+                return new MethodCallCodeFragment(nameof(NpgsqlIndexBuilderExtensions.ForNpgsqlHasNullSortOrder), annotation.Value);
             if (annotation.Name == NpgsqlAnnotationNames.IndexInclude)
                 return new MethodCallCodeFragment(nameof(NpgsqlIndexBuilderExtensions.ForNpgsqlInclude), annotation.Value);
 

src/EFCore.PG/Extensions/NpgsqlIndexBuilderExtensions.cs

@@ -1,9 +1,10 @@
-using System;
+using System;
 using System.Linq;
 using System.Linq.Expressions;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Internal;
 using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
 using Npgsql.EntityFrameworkCore.PostgreSQL.Utilities;
 
 // ReSharper disable once CheckNamespace
@@ -56,6 +57,73 @@ public static IndexBuilder ForNpgsqlHasOperators(
             return indexBuilder;
         }
 
+        /// <summary>
+        /// The PostgreSQL index collation to be used.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/indexes-collations.html
+        /// </remarks>
+        /// <param name="indexBuilder"> The builder for the index being configured. </param>
+        /// <param name="values"> The sort options to use for each column. </param>
+        /// <returns> A builder to further configure the index. </returns>
+        public static IndexBuilder ForNpgsqlHasCollation(
+            [NotNull] this IndexBuilder indexBuilder,
+            [CanBeNull, ItemNotNull] params string[] values)
+        {
+            Check.NotNull(indexBuilder, nameof(indexBuilder));
+            Check.NullButNotEmpty(values, nameof(values));
+
+            indexBuilder.Metadata.Npgsql().Collation = values;
+
+            return indexBuilder;
+        }
+
+        /// <summary>
+        /// The PostgreSQL index sort ordering to be used.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/indexes-ordering.html
+        /// </remarks>
+        /// <param name="indexBuilder"> The builder for the index being configured. </param>
+        /// <param name="values"> The sort order to use for each column. </param>
+        /// <returns> A builder to further configure the index. </returns>
+        public static IndexBuilder ForNpgsqlHasSortOrder(
+            [NotNull] this IndexBuilder indexBuilder,
+            [CanBeNull] params SortOrder[] values)
+        {
+            Check.NotNull(indexBuilder, nameof(indexBuilder));
+            Check.NullButNotEmpty(values, nameof(values));
+
+            if (!SortOrderHelper.IsDefaultSortOrder(values))
+                indexBuilder.Metadata.Npgsql().SortOrder = values;
+
+            return indexBuilder;
+        }
+
+        /// <summary>
+        /// The PostgreSQL index NULL sort ordering to be used.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/indexes-ordering.html
+        /// </remarks>
+        /// <param name="indexBuilder"> The builder for the index being configured. </param>
+        /// <param name="values"> The sort order to use for each column. </param>
+        /// <returns> A builder to further configure the index. </returns>
+        public static IndexBuilder ForNpgsqlHasNullSortOrder(
+            [NotNull] this IndexBuilder indexBuilder,
+            [CanBeNull] params NullSortOrder[] values)
+        {
+            Check.NotNull(indexBuilder, nameof(indexBuilder));
+            Check.NullButNotEmpty(values, nameof(values));
+
+            var sortOrders = indexBuilder.Metadata.Npgsql().SortOrder;
+
+            if (!SortOrderHelper.IsDefaultNullSortOrder(values, sortOrders))
+                indexBuilder.Metadata.Npgsql().NullSortOrder = values;
+
+            return indexBuilder;
+        }
+
         /// <summary>
         /// Adds an INCLUDE clause to the index definition with the specified property names.
         /// This clause specifies a list of columns which will be included as a non-key part in the index.

src/EFCore.PG/Metadata/INpgsqlIndexAnnotations.cs

@@ -1,31 +1,55 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using Microsoft.EntityFrameworkCore.Metadata;
 
 namespace Npgsql.EntityFrameworkCore.PostgreSQL.Metadata
 {
     public interface INpgsqlIndexAnnotations : IRelationalIndexAnnotations
     {
         /// <summary>
-        /// The PostgreSQL index method to be used. Null selects the default (currently btree).
+        /// The method to be used, or <c>null</c> if it hasn't been specified. <c>null</c> selects the default (currently <c>btree</c>).
         /// </summary>
         /// <remarks>
         /// http://www.postgresql.org/docs/current/static/sql-createindex.html
         /// </remarks>
         string Method { get; }
 
         /// <summary>
-        /// The PostgreSQL index operators to be used, or <c>null</c> if they have not been specified.
+        /// The column operators to be used, or <c>null</c> if they have not been specified.
         /// </summary>
         /// <remarks>
         /// https://www.postgresql.org/docs/current/static/indexes-opclass.html
         /// </remarks>
         IReadOnlyList<string> Operators { get; }
 
         /// <summary>
-        /// The PostgreSQL included property names, or <c>null</c> if they have not been specified.
+        /// The column collations to be used, or <c>null</c> if they have not been specified.
         /// </summary>
         /// <remarks>
-        /// https://www.postgresql.org/docs/current/sql-createindex.html
+        /// https://www.postgresql.org/docs/current/static/indexes-collations.html
+        /// </remarks>
+        IReadOnlyList<string> Collation { get; }
+
+        /// <summary>
+        /// The column sort orders to be used, or <c>null</c> if they have not been specified.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/indexes-ordering.html
+        /// </remarks>
+        IReadOnlyList<SortOrder> SortOrder { get; }
+
+        /// <summary>
+        /// The column NULL sort orders to be used, or <c>null</c> if they have not been specified.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/indexes-ordering.html
+        /// </remarks>
+        IReadOnlyList<NullSortOrder> NullSortOrder { get; }
+
+        /// <summary>
+        /// The included property names, or <c>null</c> if they have not been specified.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/sql-createindex.html
         /// </remarks>
         IReadOnlyList<string> IncludeProperties { get; }
     }

src/EFCore.PG/Metadata/Internal/NpgsqlAnnotationNames.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 
 namespace Npgsql.EntityFrameworkCore.PostgreSQL.Metadata.Internal
 {
@@ -11,6 +11,9 @@ public static class NpgsqlAnnotationNames
         public const string HiLoSequenceSchema = Prefix + "HiLoSequenceSchema";
         public const string IndexMethod = Prefix + "IndexMethod";
         public const string IndexOperators = Prefix + "IndexOperators";
+        public const string IndexCollation = Prefix + "IndexCollation";
+        public const string IndexSortOrder = Prefix + "IndexSortOrder";
+        public const string IndexNullSortOrder = Prefix + "IndexNullSortOrder";
         public const string IndexInclude = Prefix + "IndexInclude";
         public const string PostgresExtensionPrefix = Prefix + "PostgresExtension:";
         public const string EnumPrefix = Prefix + "Enum:";

src/EFCore.PG/Metadata/NpgsqlIndexAnnotations.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Metadata;
 using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata.Internal;
@@ -18,7 +18,7 @@ protected NpgsqlIndexAnnotations([NotNull] RelationalAnnotations annotations)
         }
 
         /// <summary>
-        /// The PostgreSQL index method to be used. Null selects the default (currently btree).
+        /// The method to be used, or <c>null</c> if it hasn't been specified. <c>null</c> selects the default (currently <c>btree</c>).
         /// </summary>
         /// <remarks>
         /// http://www.postgresql.org/docs/current/static/sql-createindex.html
@@ -30,7 +30,7 @@ public string Method
         }
 
         /// <summary>
-        /// The PostgreSQL index operators to be used, or <c>null</c> if they have not been specified.
+        /// The column operators to be used, or <c>null</c> if they have not been specified.
         /// </summary>
         /// <remarks>
         /// https://www.postgresql.org/docs/current/static/indexes-opclass.html
@@ -44,10 +44,52 @@ public string[] Operators
         IReadOnlyList<string> INpgsqlIndexAnnotations.Operators => Operators;
 
         /// <summary>
-        /// The PostgreSQL included property names, or <c>null</c> if they have not been specified.
+        /// The column collations to be used, or <c>null</c> if they have not been specified.
         /// </summary>
         /// <remarks>
-        /// https://www.postgresql.org/docs/current/sql-createindex.html
+        /// https://www.postgresql.org/docs/current/static/indexes-collations.html
+        /// </remarks>
+        public string[] Collation
+        {
+            get => (string[])Annotations.Metadata[NpgsqlAnnotationNames.IndexCollation];
+            set => SetCollation(value);
+        }
+
+        IReadOnlyList<string> INpgsqlIndexAnnotations.Collation => Collation;
+
+        /// <summary>
+        /// The column sort orders to be used, or <c>null</c> if they have not been specified.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/indexes-ordering.html
+        /// </remarks>
+        public SortOrder[] SortOrder
+        {
+            get => (SortOrder[])Annotations.Metadata[NpgsqlAnnotationNames.IndexSortOrder];
+            set => SetSortOrder(value);
+        }
+
+        IReadOnlyList<SortOrder> INpgsqlIndexAnnotations.SortOrder => SortOrder;
+
+        /// <summary>
+        /// The column NULL sort orders to be used, or <c>null</c> if they have not been specified.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/indexes-ordering.html
+        /// </remarks>
+        public NullSortOrder[] NullSortOrder
+        {
+            get => (NullSortOrder[])Annotations.Metadata[NpgsqlAnnotationNames.IndexNullSortOrder];
+            set => SetNullSortOrder(value);
+        }
+
+        IReadOnlyList<NullSortOrder> INpgsqlIndexAnnotations.NullSortOrder => NullSortOrder;
+
+        /// <summary>
+        /// The included property names, or <c>null</c> if they have not been specified.
+        /// </summary>
+        /// <remarks>
+        /// https://www.postgresql.org/docs/current/static/sql-createindex.html
         /// </remarks>
         public string[] IncludeProperties
         {
@@ -63,6 +105,15 @@ protected virtual bool SetMethod(string value)
         protected virtual bool SetOperators(string[] value)
             => Annotations.SetAnnotation(NpgsqlAnnotationNames.IndexOperators, value);
 
+        protected virtual bool SetCollation(string[] value)
+            => Annotations.SetAnnotation(NpgsqlAnnotationNames.IndexCollation, value);
+
+        protected virtual bool SetSortOrder(SortOrder[] value)
+            => Annotations.SetAnnotation(NpgsqlAnnotationNames.IndexSortOrder, value);
+
+        protected virtual bool SetNullSortOrder(NullSortOrder[] value)
+            => Annotations.SetAnnotation(NpgsqlAnnotationNames.IndexNullSortOrder, value);
+
         protected virtual bool SetIncludeProperties(string[] value)
             => Annotations.SetAnnotation(NpgsqlAnnotationNames.IndexInclude, value);
     }

src/EFCore.PG/Metadata/NullSortOrder.cs

@@ -0,0 +1,29 @@
+namespace Npgsql.EntityFrameworkCore.PostgreSQL.Metadata
+{
+    /// <summary>
+    /// Options for modifying sort ordering of <c>NULL</c>-values in indexes.
+    /// </summary>
+    public enum NullSortOrder
+    {
+        /// <summary>
+        /// Represents an unspecified sort order. The database default will be used.
+        /// </summary>
+        Unspecified = 0,
+
+        /// <summary>
+        /// Specifies that nulls sort before non-nulls.
+        /// </summary>
+        /// <remarks>
+        /// This is the default when <see cref="SortOrder.Descending"/> is specified.
+        /// </remarks>
+        NullsFirst = 1,
+
+        /// <summary>
+        /// Specifies that nulls sort after non-nulls.
+        /// </summary>
+        /// <remarks>
+        /// This is the default when <see cref="SortOrder.Descending"/> is not specified.
+        /// </remarks>
+        NullsLast = 2,
+    }
+}

src/EFCore.PG/Metadata/SortOrder.cs

@@ -0,0 +1,18 @@
+namespace Npgsql.EntityFrameworkCore.PostgreSQL.Metadata
+{
+    /// <summary>
+    /// Options for modifying sort ordering of index values.
+    /// </summary>
+    public enum SortOrder
+    {
+        /// <summary>
+        /// Specifies ascending sort order, which is the default.
+        /// </summary>
+        Ascending = 0,
+
+        /// <summary>
+        /// Specifies descending sort order.
+        /// </summary>
+        Descending = 1,
+    }
+}

src/EFCore.PG/Migrations/Internal/NpgsqlMigrationsAnnotationProvider.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using JetBrains.Annotations;
@@ -45,6 +45,12 @@ public override IEnumerable<IAnnotation> For(IIndex index)
                 yield return new Annotation(NpgsqlAnnotationNames.IndexMethod, index.Npgsql().Method);
             if (index.Npgsql().Operators != null)
                 yield return new Annotation(NpgsqlAnnotationNames.IndexOperators, index.Npgsql().Operators);
+            if (index.Npgsql().Collation != null)
+                yield return new Annotation(NpgsqlAnnotationNames.IndexCollation, index.Npgsql().Collation);
+            if (index.Npgsql().SortOrder != null)
+                yield return new Annotation(NpgsqlAnnotationNames.IndexSortOrder, index.Npgsql().SortOrder);
+            if (index.Npgsql().NullSortOrder != null)
+                yield return new Annotation(NpgsqlAnnotationNames.IndexNullSortOrder, index.Npgsql().NullSortOrder);
             if (index.Npgsql().IncludeProperties != null)
                 yield return new Annotation(NpgsqlAnnotationNames.IndexInclude, index.Npgsql().IncludeProperties);
         }