Infinity dates+timestamps

DuckDB.NET.Bindings/DuckDBDateOnly.cs

@@ -6,6 +6,26 @@ namespace DuckDB.NET.Native;
 [StructLayout(LayoutKind.Sequential)]
 public readonly struct DuckDBDateOnly(int year, byte month, byte day)
 {
+    /// <summary>
+    /// Represents positive infinity for DuckDB dates.
+    /// </summary>
+    public static readonly DuckDBDateOnly PositiveInfinity =
+        // This is the value returned by DuckDB for positive infinity dates when
+        // passed to duckdb_from_date, and it is used for backwards compatibility.
+        // It is theoretically equal to the max date value plus one day:
+        // '5881580-07-10'::date + 1
+        new(5881580, 7, 11);
+
+    /// <summary>
+    /// Represents negative infinity for DuckDB dates.
+    /// </summary>
+    public static readonly DuckDBDateOnly NegativeInfinity =
+        // This is the value returned by DuckDB for negative infinity dates when
+        // passed to duckdb_from_date, and it is used for backwards compatibility.
+        // It is theoretically equal to the min date value minus one day:
+        // '5877642-06-25 (BC)'::date - 1
+        new(-5877641, 6, 24);
+
     public int Year { get; } = year;
 
     public byte Month { get; } = month;
@@ -14,19 +34,68 @@ public readonly struct DuckDBDateOnly(int year, byte month, byte day)
 
     internal static readonly DuckDBDateOnly MinValue = FromDateTime(DateTime.MinValue);
 
+    /// <summary>
+    /// Returns true if this date represents positive or negative infinity.
+    /// </summary>
+    public bool IsInfinity => IsPositiveInfinity || IsNegativeInfinity;
+
+    /// <summary>
+    /// Returns true if this date represents positive infinity.
+    /// </summary>
+    public bool IsPositiveInfinity => Equals(PositiveInfinity);
+
+    /// <summary>
+    /// Returns true if this date represents negative infinity.
+    /// </summary>
+    public bool IsNegativeInfinity => Equals(NegativeInfinity);
+
     public static DuckDBDateOnly FromDateTime(DateTime dateTime) => new DuckDBDateOnly(dateTime.Year, (byte)dateTime.Month, (byte)dateTime.Day);
 
     public DateTime ToDateTime() => new DateTime(Year, Month, Day);
 
+#if NET6_0_OR_GREATER
+
+    public static DuckDBDateOnly FromDateOnly(DateOnly dateOnly) => new DuckDBDateOnly(dateOnly.Year, (byte)dateOnly.Month, (byte)dateOnly.Day);
+
+    public DateOnly ToDateOnly() => new DateOnly(Year, Month, Day);
+
+#endif
+
+    /// <summary>
+    /// Converts a DuckDBDate to DuckDBDateOnly, handling infinity values.
+    /// </summary>
+    public static DuckDBDateOnly FromDuckDBDate(DuckDBDate date)
+    {
+        if (date.IsPositiveInfinity)
+            return PositiveInfinity;
+        if (date.IsNegativeInfinity)
+            return NegativeInfinity;
+
+        return NativeMethods.DateTimeHelpers.DuckDBFromDate(date);
+    }
+
+    /// <summary>
+    /// Converts this DuckDBDateOnly to a DuckDBDate, handling infinity values.
+    /// </summary>
+    public DuckDBDate ToDuckDBDate()
+    {
+        if (IsPositiveInfinity)
+            return DuckDBDate.PositiveInfinity;
+        if (IsNegativeInfinity)
+            return DuckDBDate.NegativeInfinity;
+
+        return NativeMethods.DateTimeHelpers.DuckDBToDate(this);
+    }
+
     public static explicit operator DateTime(DuckDBDateOnly dateOnly) => dateOnly.ToDateTime();
-        
+
     public static explicit operator DuckDBDateOnly(DateTime dateTime) => FromDateTime(dateTime);
-        
+
 #if NET6_0_OR_GREATER
-        
-    public static implicit operator DateOnly(DuckDBDateOnly dateOnly) => new DateOnly(dateOnly.Year, dateOnly.Month, dateOnly.Day);
-        
-    public static implicit operator DuckDBDateOnly(DateOnly date) => new DuckDBDateOnly(date.Year, (byte)date.Month, (byte) date.Day);
-        
+
+    public static implicit operator DateOnly(DuckDBDateOnly dateOnly) => dateOnly.ToDateOnly();
+
+    public static implicit operator DuckDBDateOnly(DateOnly date) => DuckDBDateOnly.FromDateOnly(date);
+
 #endif
-}
+}

DuckDB.NET.Bindings/DuckDBNativeObjects.cs

@@ -115,7 +115,22 @@ public void Close()
 [StructLayout(LayoutKind.Sequential)]
 public struct DuckDBDate
 {
+    /// <summary>
+    /// Represents DuckDB's positive infinity date value.
+    /// This is the value used in the DuckDB source code for +infinity dates.
+    /// </summary>
+    public static readonly DuckDBDate PositiveInfinity = new() { Days = int.MaxValue };
+    /// <summary>
+    /// Represents DuckDB's negative infinity date value.
+    /// This is the value used in the DuckDB source code for -infinity dates.
+    /// </summary>
+    public static readonly DuckDBDate NegativeInfinity = new() { Days = -int.MaxValue };
+
     public int Days { get; set; }
+
+    public bool IsInfinity => IsPositiveInfinity || IsNegativeInfinity;
+    public bool IsPositiveInfinity => Days == int.MaxValue;
+    public bool IsNegativeInfinity => Days == -int.MaxValue;
 }
 
 [StructLayout(LayoutKind.Sequential)]
@@ -140,7 +155,22 @@ public struct DuckDBTimeTz
 [StructLayout(LayoutKind.Sequential)]
 public struct DuckDBTimestampStruct
 {
+    /// <summary>
+    /// Represents DuckDB's positive infinity timestamp value.
+    /// This is the value used in the DuckDB source code for +infinity timestamps.
+    /// </summary>
+    public static readonly DuckDBTimestampStruct PositiveInfinity = new() { Micros = long.MaxValue };
+    /// <summary>
+    /// Represents DuckDB's negative infinity timestamp value.
+    /// This is the value used in the DuckDB source code for -infinity timestamps.
+    /// </summary>
+    public static readonly DuckDBTimestampStruct NegativeInfinity = new() { Micros = -long.MaxValue };
+
     public long Micros { get; set; }
+
+    public bool IsInfinity => IsPositiveInfinity || IsNegativeInfinity;
+    public bool IsPositiveInfinity => Micros == long.MaxValue;
+    public bool IsNegativeInfinity => Micros == -long.MaxValue;
 }
 
 [StructLayout(LayoutKind.Sequential)]

DuckDB.NET.Bindings/DuckDBTimestamp.cs

@@ -6,9 +6,40 @@ namespace DuckDB.NET.Native;
 [StructLayout(LayoutKind.Sequential)]
 public readonly struct DuckDBTimestamp(DuckDBDateOnly date, DuckDBTimeOnly time)
 {
+    /// <summary>
+    /// Represents positive infinity for DuckDB timestamps.
+    /// </summary>
+    public static readonly DuckDBTimestamp PositiveInfinity =
+        // This is the max timestamp value + 1 microsecond (because timestamps are represented as an int64 of microseconds)
+        // Theoretically: '294247-01-10 04:00:54.775806'::timestamp + INTERVAL '1 microsecond'
+        new(new DuckDBDateOnly(294247, 1, 10), new DuckDBTimeOnly(4, 0, 54, 775807));
+
+    /// <summary>
+    /// Represents negative infinity for DuckDB timestamps.
+    /// </summary>
+    public static readonly DuckDBTimestamp NegativeInfinity =
+        // This is the min timestamp value - 1 microsecond (because timestamps are represented as an int64 of microseconds)
+        // Theoretically: '290309-12-22 (BC) 00:00:00.000000'::timestamp - INTERVAL '1 microsecond'
+        new(new DuckDBDateOnly(-290308, 12, 21), new DuckDBTimeOnly(23, 59, 59, 999999));
+
     public DuckDBDateOnly Date { get; } = date;
     public DuckDBTimeOnly Time { get; } = time;
 
+    /// <summary>
+    /// Returns true if this timestamp represents positive or negative infinity.
+    /// </summary>
+    public bool IsInfinity => IsPositiveInfinity || IsNegativeInfinity;
+
+    /// <summary>
+    /// Returns true if this timestamp represents positive infinity.
+    /// </summary>
+    public bool IsPositiveInfinity => Equals(PositiveInfinity);
+
+    /// <summary>
+    /// Returns true if this timestamp represents negative infinity.
+    /// </summary>
+    public bool IsNegativeInfinity => Equals(NegativeInfinity);
+
     public DateTime ToDateTime()
     {
         return new DateTime(Date.Year, Date.Month, Date.Day).AddTicks(Time.Ticks);
@@ -18,4 +49,33 @@ public static DuckDBTimestamp FromDateTime(DateTime dateTime)
     {
         return new DuckDBTimestamp(DuckDBDateOnly.FromDateTime(dateTime), DuckDBTimeOnly.FromDateTime(dateTime));
     }
-}
+
+    /// <summary>
+    /// Converts a DuckDBTimestampStruct to DuckDBTimestamp, handling infinity values.
+    /// </summary>
+    public static DuckDBTimestamp FromDuckDBTimestampStruct(DuckDBTimestampStruct timestampStruct)
+    {
+        if (timestampStruct.IsPositiveInfinity)
+            return PositiveInfinity;
+        if (timestampStruct.IsNegativeInfinity)
+            return NegativeInfinity;
+
+        return NativeMethods.DateTimeHelpers.DuckDBFromTimestamp(timestampStruct);
+    }
+
+    /// <summary>
+    /// Converts this DuckDBTimestamp to a DuckDBTimestampStruct, handling infinity values.
+    /// </summary>
+    public DuckDBTimestampStruct ToDuckDBTimestampStruct()
+    {
+        if (IsPositiveInfinity)
+            return DuckDBTimestampStruct.PositiveInfinity;
+        if (IsNegativeInfinity)
+            return DuckDBTimestampStruct.NegativeInfinity;
+
+        return NativeMethods.DateTimeHelpers.DuckDBToTimestamp(this);
+    }
+
+    public static implicit operator DateTime(DuckDBTimestamp timestamp) => timestamp.ToDateTime();
+    public static implicit operator DuckDBTimestamp(DateTime timestamp) => DuckDBTimestamp.FromDateTime(timestamp);
+}

DuckDB.NET.Bindings/DuckDBWrapperObjects.cs

@@ -101,7 +101,7 @@ protected override bool ReleaseHandle()
         {
             value.Dispose();
         }
-        
+
         NativeMethods.Value.DuckDBDestroyValue(ref handle);
         return true;
     }
@@ -140,26 +140,26 @@ public T GetValue<T>()
 
             DuckDBType.Float => Cast(NativeMethods.Value.DuckDBGetFloat(this)),
             DuckDBType.Double => Cast(NativeMethods.Value.DuckDBGetDouble(this)),
-            
+
             DuckDBType.Decimal => Cast(decimal.Parse(NativeMethods.Value.DuckDBGetVarchar(this), NumberStyles.Any, CultureInfo.InvariantCulture)),
-            
+
             DuckDBType.Uuid => Cast(new Guid(NativeMethods.Value.DuckDBGetVarchar(this))),
-            
+
             DuckDBType.HugeInt => Cast(NativeMethods.Value.DuckDBGetHugeInt(this).ToBigInteger()),
             DuckDBType.UnsignedHugeInt => Cast(NativeMethods.Value.DuckDBGetUHugeInt(this).ToBigInteger()),
-            
+
             DuckDBType.Varchar => Cast(NativeMethods.Value.DuckDBGetVarchar(this)),
 
 #if NET6_0_OR_GREATER
-            DuckDBType.Date => Cast((DateOnly)NativeMethods.DateTimeHelpers.DuckDBFromDate(NativeMethods.Value.DuckDBGetDate(this))),
+            DuckDBType.Date => Cast((DateOnly)DuckDBDateOnly.FromDuckDBDate(NativeMethods.Value.DuckDBGetDate(this))),
             DuckDBType.Time => Cast((TimeOnly)NativeMethods.DateTimeHelpers.DuckDBFromTime(NativeMethods.Value.DuckDBGetTime(this))),
 #else
-            DuckDBType.Date => Cast(NativeMethods.DateTimeHelpers.DuckDBFromDate(NativeMethods.Value.DuckDBGetDate(this)).ToDateTime()),
+            DuckDBType.Date => Cast(DuckDBDateOnly.FromDuckDBDate(NativeMethods.Value.DuckDBGetDate(this)).ToDateTime()),
             DuckDBType.Time => Cast(NativeMethods.DateTimeHelpers.DuckDBFromTime(NativeMethods.Value.DuckDBGetTime(this)).ToDateTime()),
 #endif
             //DuckDBType.TimeTz => expr,
             DuckDBType.Interval => Cast((TimeSpan)NativeMethods.Value.DuckDBGetInterval(this)),
-            DuckDBType.Timestamp => Cast(NativeMethods.DateTimeHelpers.DuckDBFromTimestamp(NativeMethods.Value.DuckDBGetTimestamp(this)).ToDateTime()),
+            DuckDBType.Timestamp => Cast(DuckDBTimestamp.FromDuckDBTimestampStruct(NativeMethods.Value.DuckDBGetTimestamp(this)).ToDateTime()),
             //DuckDBType.TimestampS => expr,
             //DuckDBType.TimestampMs => expr,
             //DuckDBType.TimestampNs => expr,

DuckDB.NET.Bindings/NativeMethods/NativeMethods.DateTime.cs

@@ -30,5 +30,27 @@ public static class DateTimeHelpers
 
         [DllImport(DuckDbLibrary, CallingConvention = CallingConvention.Cdecl, EntryPoint = "duckdb_to_timestamp")]
         public static extern DuckDBTimestampStruct DuckDBToTimestamp(DuckDBTimestamp dateStruct);
+
+        // NOTE: for boolean return values, MarshalAs(UnmanagedType.I1) is used because the default is to use 4-byte Win32 BOOLs
+        // https://learn.microsoft.com/en-us/dotnet/standard/native-interop/customize-struct-marshalling#customizing-boolean-field-marshalling
+        [DllImport(DuckDbLibrary, CallingConvention = CallingConvention.Cdecl, EntryPoint = "duckdb_is_finite_date")]
+        [return: MarshalAs(UnmanagedType.I1)]
+        public static extern bool DuckDBIsFiniteDate(DuckDBDate date);
+
+        [DllImport(DuckDbLibrary, CallingConvention = CallingConvention.Cdecl, EntryPoint = "duckdb_is_finite_timestamp")]
+        [return: MarshalAs(UnmanagedType.I1)]
+        public static extern bool DuckDBIsFiniteTimestamp(DuckDBTimestampStruct ts);
+
+        [DllImport(DuckDbLibrary, CallingConvention = CallingConvention.Cdecl, EntryPoint = "duckdb_is_finite_timestamp_s")]
+        [return: MarshalAs(UnmanagedType.I1)]
+        public static extern bool DuckDBIsFiniteTimestampS(DuckDBTimestampStruct ts);
+
+        [DllImport(DuckDbLibrary, CallingConvention = CallingConvention.Cdecl, EntryPoint = "duckdb_is_finite_timestamp_ms")]
+        [return: MarshalAs(UnmanagedType.I1)]
+        public static extern bool DuckDBIsFiniteTimestampMs(DuckDBTimestampStruct ts);
+
+        [DllImport(DuckDbLibrary, CallingConvention = CallingConvention.Cdecl, EntryPoint = "duckdb_is_finite_timestamp_ns")]
+        [return: MarshalAs(UnmanagedType.I1)]
+        public static extern bool DuckDBIsFiniteTimestampNs(DuckDBTimestampStruct ts);
     }
-}
+}