From 3f96e704d140408a62c8964f753c20e08380971b Mon Sep 17 00:00:00 2001
From: "Oleg V. Kozlyuk" <elquentaro@gmail.com>
Date: Fri, 10 Mar 2023 14:07:57 +0300
Subject: [PATCH] Another piece for DateOnly puzzle (#282)

---
 ClickHouse.Client/Types/AbstractDateTimeType.cs | 4 ++++
 ClickHouse.Client/Types/DateType.cs             | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/ClickHouse.Client/Types/AbstractDateTimeType.cs b/ClickHouse.Client/Types/AbstractDateTimeType.cs
index 4311930e..e8100ffe 100644
--- a/ClickHouse.Client/Types/AbstractDateTimeType.cs
+++ b/ClickHouse.Client/Types/AbstractDateTimeType.cs
@@ -8,6 +8,10 @@ internal abstract class AbstractDateTimeType : ParameterizedType
     // DateTime.UnixEpoch is not available on .NET 4.8
     public static readonly DateTime DateTimeEpochStart = DateTimeOffset.FromUnixTimeSeconds(0).UtcDateTime;
 
+#if NET6_0_OR_GREATER
+    public static readonly DateOnly DateOnlyEpochStart = new DateOnly(1970,1,1);
+#endif
+
     public override Type FrameworkType => typeof(DateTime);
 
     public DateTimeZone TimeZone { get; set; }
diff --git a/ClickHouse.Client/Types/DateType.cs b/ClickHouse.Client/Types/DateType.cs
index b86cd645..ffd4e94c 100644
--- a/ClickHouse.Client/Types/DateType.cs
+++ b/ClickHouse.Client/Types/DateType.cs
@@ -16,6 +16,14 @@ internal class DateType : AbstractDateTimeType
 
     public override void Write(ExtendedBinaryWriter writer, object value)
     {
+#if NET6_0_OR_GREATER
+        if (value is DateOnly @do)
+        {
+            var delta = @do.DayNumber - DateOnlyEpochStart.DayNumber;
+            writer.Write((ushort)delta);
+            return;
+        }
+#endif
         var sinceEpoch = ((DateTime)value).Date - DateTimeEpochStart;
         writer.Write(Convert.ToUInt16(sinceEpoch.TotalDays));
     }