Generate Sqlite create table comments

EFCore.Sqlite.slnf

@@ -9,7 +9,6 @@
       "src\\EFCore.Relational\\EFCore.Relational.csproj",
       "src\\EFCore.Sqlite.Core\\EFCore.Sqlite.Core.csproj",
       "src\\EFCore.Sqlite.NTS\\EFCore.Sqlite.NTS.csproj",
-      "src\\EFCore.Sqlite\\EFCore.Sqlite.csproj",
       "src\\EFCore\\EFCore.csproj",
       "src\\Microsoft.Data.Sqlite.Core\\Microsoft.Data.Sqlite.Core.csproj",
       "test\\EFCore.Analyzers.Tests\\EFCore.Analyzers.Test.csproj",

src/EFCore.Relational/Query/QuerySqlGenerator.cs

@@ -3,9 +3,7 @@
 
 using System;
 using System.Collections.Generic;
-using System.Data.Common;
 using System.Diagnostics;
-using System.IO;
 using System.Linq;
 using System.Linq.Expressions;
 using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
@@ -72,11 +70,6 @@ public virtual IRelationalCommand GetCommand(SelectExpression selectExpression)
         /// </summary>
         protected virtual string AliasSeparator { get; } = " AS ";
 
-        /// <summary>
-        ///     The default single line comment prefix.
-        /// </summary>
-        protected virtual string SingleLineCommentToken { get; } = "--";
-
         protected virtual IRelationalCommandBuilder Sql => _relationalCommandBuilder;
 
         protected virtual void GenerateTagsHeaderComment(SelectExpression selectExpression)
@@ -85,16 +78,9 @@ protected virtual void GenerateTagsHeaderComment(SelectExpression selectExpressi
             {
                 foreach (var tag in selectExpression.Tags)
                 {
-                    using (var reader = new StringReader(tag))
-                    {
-                        string line;
-                        while ((line = reader.ReadLine()) != null)
-                        {
-                            _relationalCommandBuilder.Append(SingleLineCommentToken).Append(" ").AppendLine(line);
-                        }
-                    }
-
-                    _relationalCommandBuilder.AppendLine();
+                    _relationalCommandBuilder
+                        .AppendLines(_sqlGenerationHelper.GenerateComment(tag))
+                        .AppendLine();
                 }
             }
         }

src/EFCore.Relational/Storage/ISqlGenerationHelper.cs

@@ -33,6 +33,11 @@ public interface ISqlGenerationHelper
         /// </summary>
         string BatchTerminator { get; }
 
+        /// <summary>
+        ///     The default single-line comment prefix.
+        /// </summary>
+        string SingleLineCommentToken { get; }
+
         /// <summary>
         ///     Generates a valid parameter name for the given candidate name.
         /// </summary>
@@ -98,5 +103,12 @@ public interface ISqlGenerationHelper
         /// <param name="name"> The identifier to delimit. </param>
         /// <param name="schema"> The schema of the identifier. </param>
         void DelimitIdentifier([NotNull] StringBuilder builder, [NotNull] string name, [CanBeNull] string schema);
+
+        /// <summary>
+        ///     Generates a SQL comment.
+        /// </summary>
+        /// <param name="text"> The comment text. </param>
+        /// <returns> The generated SQL. </returns>
+        string GenerateComment([NotNull] string text);
     }
 }

src/EFCore.Relational/Storage/RelationalSqlGenerationHelper.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System.IO;
 using System.Text;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Utilities;
@@ -43,6 +44,11 @@ public RelationalSqlGenerationHelper([NotNull] RelationalSqlGenerationHelperDepe
         /// </summary>
         public virtual string BatchTerminator => string.Empty;
 
+        /// <summary>
+        ///     The default single-line comment prefix.
+        /// </summary>
+        public virtual string SingleLineCommentToken => "--";
+
         /// <summary>
         ///     Generates a valid parameter name for the given candidate name.
         /// </summary>
@@ -159,5 +165,27 @@ public virtual void DelimitIdentifier(StringBuilder builder, string name, string
 
             DelimitIdentifier(builder, name);
         }
+
+        /// <summary>
+        ///     Generates a SQL comment.
+        /// </summary>
+        /// <param name="text"> The comment text. </param>
+        /// <returns> The generated SQL. </returns>
+        public virtual string GenerateComment(string text)
+        {
+            Check.NotEmpty(text, nameof(text));
+
+            var builder = new StringBuilder();
+            using (var reader = new StringReader(text))
+            {
+                string line;
+                while ((line = reader.ReadLine()) != null)
+                {
+                    builder.Append(SingleLineCommentToken).Append(" ").AppendLine(line);
+                }
+            }
+
+            return builder.ToString();
+        }
     }
 }

src/EFCore.Sqlite.Core/Migrations/SqliteMigrationsSqlGenerator.cs

@@ -345,7 +345,87 @@ protected override void Generate(
                 }
             }
 
-            base.Generate(operation, model, builder, terminate);
+            if (string.IsNullOrEmpty(operation.Comment))
+            {
+                base.Generate(operation, model, builder, terminate);
+            }
+            else
+            {
+                builder
+                   .Append("CREATE TABLE ")
+                   .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier(operation.Name, operation.Schema))
+                   .AppendLine(" (");
+
+                using (builder.Indent())
+                {
+                    builder
+                        .AppendLines(Dependencies.SqlGenerationHelper.GenerateComment(operation.Comment))
+                        .AppendLine();
+                    CreateTableColumns(operation, model, builder);
+                    CreateTableConstraints(operation, model, builder);
+                    builder.AppendLine();
+                }
+
+                builder.Append(")");
+
+                if (terminate)
+                {
+                    builder.AppendLine(Dependencies.SqlGenerationHelper.StatementTerminator);
+                    EndStatement(builder);
+                }
+            }
+        }
+
+        /// <summary>
+        ///     Generates a SQL fragment for the column definitions in an <see cref="CreateTableOperation" />.
+        /// </summary>
+        /// <param name="operation"> The operation. </param>
+        /// <param name="model"> The target model which may be <c>null</c> if the operations exist without a model. </param>
+        /// <param name="builder"> The command builder to use to add the SQL fragment. </param>
+        protected override void CreateTableColumns(
+            CreateTableOperation operation,
+            IModel model,
+            MigrationCommandListBuilder builder)
+        {
+            Check.NotNull(operation, nameof(operation));
+            Check.NotNull(builder, nameof(builder));
+
+            if (!operation.Columns.Any(c => !string.IsNullOrEmpty(c.Comment)))
+            {
+                base.CreateTableColumns(operation, model, builder);
+            }
+            else
+            {
+                CreateTableColumnsWithComments(operation, model, builder);
+            }
+        }
+
+        private void CreateTableColumnsWithComments(
+            CreateTableOperation operation,
+            IModel model,
+            MigrationCommandListBuilder builder)
+        {
+            for (var i = 0; i < operation.Columns.Count; i++)
+            {
+                var column = operation.Columns[i];
+
+                if (i > 0)
+                {
+                    builder.AppendLine();
+                }
+
+                if (!string.IsNullOrEmpty(column.Comment))
+                {
+                    builder.AppendLines(Dependencies.SqlGenerationHelper.GenerateComment(column.Comment));
+                }
+
+                ColumnDefinition(column, model, builder);
+
+                if (i != operation.Columns.Count - 1)
+                {
+                    builder.AppendLine(",");
+                }
+            }
         }
 
         /// <summary>

test/EFCore.Sqlite.FunctionalTests/SqliteMigrationSqlGeneratorTest.cs

@@ -506,6 +506,131 @@ public virtual void CreateTableOperation_old_autoincrement_annotation()
 ");
         }
 
+        [ConditionalFact]
+        public virtual void CreateTableOperation_has_comment()
+        {
+            Generate(
+                new CreateTableOperation
+                {
+                    Name = "People",
+                    Columns =
+                    {
+                        new AddColumnOperation
+                        {
+                            Name = "Id",
+                            Table = "People",
+                            ClrType = typeof(int),
+                            IsNullable = false,
+                            Comment = "The ID"
+                        },
+                        new AddColumnOperation
+                        {
+                            Name = "UncommentedColumn1",
+                            Table = "People",
+                            ClrType = typeof(string),
+                            IsNullable = false
+                        },
+                        new AddColumnOperation
+                        {
+                            Name = "UncommentedColumn2",
+                            Table = "People",
+                            ClrType = typeof(string),
+                            IsNullable = false
+                        },
+                        new AddColumnOperation
+                        {
+                            Name = "Name",
+                            Table = "People",
+                            ClrType = typeof(string),
+                            IsNullable = false,
+                            Comment = "The Name"
+                        }
+                    }
+                });
+
+            AssertSql(
+                @"CREATE TABLE ""People"" (
+    -- The ID
+    ""Id"" INTEGER NOT NULL,
+
+    ""UncommentedColumn1"" TEXT NOT NULL,
+
+    ""UncommentedColumn2"" TEXT NOT NULL,
+
+    -- The Name
+    ""Name"" TEXT NOT NULL
+);
+");
+        }
+
+        [ConditionalFact]
+        public virtual void CreateTableOperation_has_multi_line_comment()
+        {
+            Generate(
+                new CreateTableOperation
+                {
+                    Name = "People",
+                    Columns =
+                    {
+                        new AddColumnOperation
+                        {
+                            Name = "Id",
+                            Table = "People",
+                            ClrType = typeof(int),
+                            IsNullable = false,
+                            Comment = @"This is a multi-line
+comment.
+More information can
+be found in the docs."
+
+                        },
+                    }
+                });
+
+            AssertSql(
+                @"CREATE TABLE ""People"" (
+    -- This is a multi-line
+    -- comment.
+    -- More information can
+    -- be found in the docs.
+    ""Id"" INTEGER NOT NULL
+);
+");
+        }
+
+        [ConditionalFact]
+        public virtual void CreateTableOperation_has_multi_line_table_comment()
+        {
+            Generate(
+                new CreateTableOperation
+                {
+                    Name = "People",
+                    Comment = @"Table level comment
+that continues onto another line",
+                    Columns =
+                    {
+                        new AddColumnOperation
+                        {
+                            Name = "Id",
+                            Table = "People",
+                            ClrType = typeof(int),
+                            IsNullable = false,
+                            Comment = "My Comment"
+                        },
+                    }
+                });
+
+            AssertSql(
+                @"CREATE TABLE ""People"" (
+    -- Table level comment
+    -- that continues onto another line
+
+    -- My Comment
+    ""Id"" INTEGER NOT NULL
+);
+");
+        }
+
         public SqliteMigrationSqlGeneratorTest()
             : base(SqliteTestHelpers.Instance)
         {