Feat ADO.NET: decimal type with arbitrary precision/scale (#500)

KirillKurdyukov · web-flow · commit a8563bb60b1b · 2025-08-08T09:40:15.000+03:00
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
@@ -22,6 +22,7 @@ jobs:
         ports: [ "2135:2135", "2136:2136", "8765:8765" ]
         env:
           YDB_LOCAL_SURVIVE_RESTART: true
+          YDB_FEATURE_FLAGS: enable_parameterized_decimal
         options: '--name ydb-local -h localhost'
 
     steps:
diff --git a/src/Ydb.Sdk/CHANGELOG.md b/src/Ydb.Sdk/CHANGELOG.md
@@ -1,4 +1,5 @@
-- Fixed bug: interval value parsing in microseconds and double instead of ticks.
+- Feat ADO.NET: decimal type with arbitrary precision/scale ([#498](https://github.com/ydb-platform/ydb-dotnet-sdk/issues/498)).
+- Fixed bug: interval value parsing in microseconds and double instead of ticks ([#497](https://github.com/ydb-platform/ydb-dotnet-sdk/issues/497)).
 - ADO.NET: Changed `IBulkUpsertImporter.AddRowAsync` signature: `object?[] row` → `params object[]`.
 
 ## v0.21.0
diff --git a/src/Ydb.Sdk/src/Ado/Schema/SchemaUtils.cs b/src/Ydb.Sdk/src/Ado/Schema/SchemaUtils.cs
@@ -12,7 +12,7 @@ internal static class SchemaUtils
                 Type.Types.PrimitiveTypeId.String => "Bytes",
                 _ => type.TypeId.ToString()
             },
-        Type.TypeOneofCase.DecimalType => "Decimal(22, 9)",
+        Type.TypeOneofCase.DecimalType => $"Decimal({type.DecimalType.Precision}, {type.DecimalType.Scale})",
         _ => "Unknown"
     };
 
diff --git a/src/Ydb.Sdk/src/Ado/YdbParameter.cs b/src/Ydb.Sdk/src/Ado/YdbParameter.cs
@@ -2,6 +2,7 @@
 using System.Data;
 using System.Data.Common;
 using System.Diagnostics.CodeAnalysis;
+using Google.Protobuf.WellKnownTypes;
 using Ydb.Sdk.Value;
 
 namespace Ydb.Sdk.Ado;
@@ -30,8 +31,6 @@ public sealed class YdbParameter : DbParameter
         { DbType.Byte, YdbValue.MakeOptionalUint8() },
         { DbType.DateTime2, YdbValue.MakeOptionalTimestamp() },
         { DbType.DateTimeOffset, YdbValue.MakeOptionalTimestamp() },
-        { DbType.Decimal, YdbValue.MakeOptionalDecimal() },
-        { DbType.Currency, YdbValue.MakeOptionalDecimal() },
         { DbType.Guid, YdbValue.MakeOptionalUuid() }
     };
 
@@ -93,10 +92,23 @@ public override string SourceColumn
     public override bool SourceColumnNullMapping { get; set; }
     public override int Size { get; set; }
 
+    public override byte Precision { get; set; }
+    public override byte Scale { get; set; }
+
     internal YdbValue YdbValue => Value switch
     {
         YdbValue ydbValue => ydbValue,
         null or DBNull when YdbNullByDbType.TryGetValue(DbType, out var value) => value,
+        null or DBNull when DbType is DbType.Decimal or DbType.Currency => Precision == 0 && Scale == 0
+            ? YdbValue.MakeOptionalDecimal()
+            : new YdbValue(
+                new Type
+                {
+                    OptionalType = new OptionalType
+                        { Item = new Type { DecimalType = new DecimalType { Precision = Precision, Scale = Scale } } }
+                },
+                new Ydb.Value { NullFlagValue = new NullValue() }
+            ),
         string valueString when DbType is DbType.String or DbType.AnsiString or DbType.AnsiStringFixedLength
             or DbType.StringFixedLength or DbType.Object => YdbValue.MakeUtf8(valueString),
         bool boolValue when DbType is DbType.Boolean or DbType.Object => YdbValue.MakeBool(boolValue),
@@ -126,7 +138,9 @@ string valueString when DbType is DbType.String or DbType.AnsiString or DbType.A
         },
         long longValue when DbType is DbType.Int64 or DbType.Object => YdbValue.MakeInt64(longValue),
         decimal decimalValue when DbType is DbType.Decimal or DbType.Currency or DbType.Object =>
-            YdbValue.MakeDecimal(decimalValue),
+            Precision == 0 && Scale == 0
+                ? YdbValue.MakeDecimal(decimalValue)
+                : YdbValue.MakeDecimalWithPrecision(decimalValue, precision: Precision, scale: Scale),
         ulong ulongValue when DbType is DbType.UInt64 or DbType.Object => YdbValue.MakeUint64(ulongValue),
         uint uintValue => DbType switch
         {
diff --git a/src/Ydb.Sdk/src/Value/YdbValue.cs b/src/Ydb.Sdk/src/Value/YdbValue.cs
@@ -75,7 +75,7 @@ private static string ToYql(Type type) =>
         type.TypeCase switch
         {
             Type.TypeOneofCase.TypeId => type.TypeId.ToString(),
-            Type.TypeOneofCase.DecimalType => "Decimal(22, 9)",
+            Type.TypeOneofCase.DecimalType => $"Decimal({type.DecimalType.Precision}, {type.DecimalType.Scale})",
             Type.TypeOneofCase.OptionalType => $"{ToYql(type.OptionalType.Item)}?",
             Type.TypeOneofCase.ListType => $"List<{ToYql(type.ListType.Item)}>",
             Type.TypeOneofCase.VoidType => "Void",
diff --git a/src/Ydb.Sdk/src/Value/YdbValueBuilder.cs b/src/Ydb.Sdk/src/Value/YdbValueBuilder.cs
@@ -86,86 +86,33 @@ public static YdbValue MakeUuid(Guid guid)
             new Ydb.Value { Low128 = low, High128 = high });
     }
 
-    private static byte GetDecimalScale(decimal value)
+    public static YdbValue MakeDecimalWithPrecision(decimal value, uint precision, uint scale)
     {
-        var bits = decimal.GetBits(value);
-        var flags = bits[3];
-        var scale = (byte)((flags >> 16) & 0x7F);
-        return scale;
-    }
-
-    private static uint GetDecimalPrecision(decimal value)
-    {
-        var bits = decimal.GetBits(value);
-        value = new decimal(lo: bits[0], mid: bits[1], hi: bits[2], isNegative: false, scale: 0);
-
-        var precision = 0u;
-        while (value != decimal.Zero)
-        {
-            value = Math.Round(value / 10);
-            precision++;
-        }
-
-        return precision;
-    }
+        value *= 1.00000000000000000000000000000m; // 29 zeros, max supported by c# decimal
+        value = Math.Round(value, (int)scale);
 
-    private static Ydb.Value MakeDecimalValue(decimal value)
-    {
+        var type = new Type { DecimalType = new DecimalType { Scale = scale, Precision = precision } };
         var bits = decimal.GetBits(value);
-
-        var low64 = ((ulong)(uint)bits[1] << 32) + (uint)bits[0];
-        var high64 = (ulong)(uint)bits[2];
+        var lo = ((ulong)bits[1] << 32) + (uint)bits[0];
+        var hi = (ulong)bits[2];
 
         unchecked
         {
-            // make value negative
             if (value < 0)
             {
-                low64 = ~low64;
-                high64 = ~high64;
+                lo = ~lo;
+                hi = ~hi;
 
-                if (low64 == (ulong)-1L)
+                if (lo == (ulong)-1L)
                 {
-                    high64 += 1;
+                    hi += 1;
                 }
 
-                low64 += 1;
+                lo += 1;
             }
         }
 
-        return new Ydb.Value
-        {
-            Low128 = low64,
-            High128 = high64
-        };
-    }
-
-    public static YdbValue MakeDecimalWithPrecision(decimal value, uint? precision = null, uint? scale = null)
-    {
-        var valueScale = GetDecimalScale(value);
-        var valuePrecision = GetDecimalPrecision(value);
-        scale ??= GetDecimalScale(value);
-        precision ??= valuePrecision;
-
-        if ((int)valuePrecision - valueScale > (int)precision - scale)
-        {
-            throw new InvalidCastException(
-                $"Decimal with precision ({valuePrecision}, {valueScale}) can't fit into ({precision}, {scale})");
-        }
-
-        // multiply for fill value with trailing zeros
-        // ex: 123.45 -> 123.4500...00
-        value *= 1.00000000000000000000000000000m; // 29 zeros, max supported by c# decimal
-        value = Math.Round(value, (int)scale);
-
-        var type = new Type
-        {
-            DecimalType = new DecimalType { Scale = (uint)scale, Precision = (uint)precision }
-        };
-
-        var ydbValue = MakeDecimalValue(value);
-
-        return new YdbValue(type, ydbValue);
+        return new YdbValue(type, new Ydb.Value { Low128 = lo, High128 = hi });
     }
 
     public static YdbValue MakeDecimal(decimal value) => MakeDecimalWithPrecision(value, 22, 9);
@@ -175,7 +122,8 @@ private static YdbValue MakeOptional(YdbValue value) =>
             new Type { OptionalType = new OptionalType { Item = value._protoType } },
             value.TypeId != YdbTypeId.OptionalType
                 ? value._protoValue
-                : new Ydb.Value { NestedValue = value._protoValue });
+                : new Ydb.Value { NestedValue = value._protoValue }
+        );
 
     // TODO: MakeEmptyList with complex types
     public static YdbValue MakeEmptyList(YdbTypeId typeId) =>
diff --git a/src/Ydb.Sdk/src/Value/YdbValueParser.cs b/src/Ydb.Sdk/src/Value/YdbValueParser.cs
@@ -150,31 +150,28 @@ public Guid GetUuid()
     public decimal GetDecimal()
     {
         EnsureType(Type.TypeOneofCase.DecimalType);
-        var low64 = _protoValue.Low128;
-        var high64 = _protoValue.High128;
-
+        var lo = _protoValue.Low128;
+        var hi = _protoValue.High128;
         var scale = _protoType.DecimalType.Scale;
-
-        var isNegative = false;
+        var isNegative = (hi & 0x8000_0000_0000_0000UL) != 0;
 
         unchecked
         {
-            if (high64 >> 63 == 1) // if negative
+            if (isNegative)
             {
-                isNegative = true;
-                if (low64 == 0)
-                {
-                    high64 -= 1;
-                }
+                if (lo == 0)
+                    hi--;
 
-                low64 -= 1;
-
-                low64 = ~low64;
-                high64 = ~high64;
+                lo--;
+                lo = ~lo;
+                hi = ~hi;
             }
         }
 
-        return new decimal((int)low64, (int)(low64 >> 32), (int)high64, isNegative, (byte)scale);
+        if (hi >> 32 != 0)
+            throw new OverflowException("Value does not fit into decimal");
+
+        return new decimal((int)lo, (int)(lo >> 32), (int)hi, isNegative, (byte)scale);
     }
 
     public bool? GetOptionalBool() => GetOptional()?.GetBool();
diff --git a/src/Ydb.Sdk/test/Ydb.Sdk.Ado.Tests/Value/YdbValueUnitTests.cs b/src/Ydb.Sdk/test/Ydb.Sdk.Ado.Tests/Value/YdbValueUnitTests.cs
@@ -274,34 +274,23 @@ public void DecimalType()
 
         Assert.Null(YdbValue.MakeOptionalDecimal().GetOptionalDecimal());
         Assert.Null((decimal?)(YdbValue)(decimal?)null);
-
-        Assert.Equal("Decimal with precision (30, 0) can't fit into (22, 9)",
-            Assert.Throws<InvalidCastException>(() => YdbValue.MakeDecimal(decimal.MaxValue)).Message);
     }
 
     [Fact]
     public void DecimalTypeWithPrecision()
     {
-        Assert.Equal(12345m, YdbValue.MakeDecimalWithPrecision(12345m).GetDecimal());
+        Assert.Equal(12345m, YdbValue.MakeDecimal(12345m).GetDecimal());
         Assert.Equal(12345m, YdbValue.MakeDecimalWithPrecision(12345m, precision: 5, scale: 0).GetDecimal());
         Assert.Equal(12345m, YdbValue.MakeDecimalWithPrecision(12345m, precision: 7, scale: 2).GetDecimal());
         Assert.Equal(123.46m, YdbValue.MakeDecimalWithPrecision(123.456m, precision: 5, scale: 2).GetDecimal());
         Assert.Equal(-18446744073.709551616m,
-            YdbValue.MakeDecimalWithPrecision(-18446744073.709551616m).GetDecimal());
+            YdbValue.MakeDecimal(-18446744073.709551616m).GetDecimal());
         Assert.Equal(-18446744073.709551616m,
             YdbValue.MakeDecimalWithPrecision(-18446744073.709551616m, precision: 21, scale: 9).GetDecimal());
         Assert.Equal(-18446744074m,
             YdbValue.MakeDecimalWithPrecision(-18446744073.709551616m, precision: 12, scale: 0).GetDecimal());
         Assert.Equal(-184467440730709551616m,
             YdbValue.MakeDecimalWithPrecision(-184467440730709551616m, precision: 21, scale: 0).GetDecimal());
-
-
-        Assert.Equal("Decimal with precision (5, 0) can't fit into (4, 0)",
-            Assert.Throws<InvalidCastException>(() => YdbValue.MakeDecimalWithPrecision(12345m, precision: 4))
-                .Message);
-        Assert.Equal("Decimal with precision (5, 0) can't fit into (5, 2)",
-            Assert.Throws<InvalidCastException>(() => YdbValue.MakeDecimalWithPrecision(12345m, precision: 5, 2))
-                .Message);
     }
 
     [Fact]
diff --git a/src/Ydb.Sdk/test/Ydb.Sdk.Ado.Tests/YdbCommandTests.cs b/src/Ydb.Sdk/test/Ydb.Sdk.Ado.Tests/YdbCommandTests.cs
@@ -1,4 +1,5 @@
 using System.Data;
+using System.Globalization;
 using System.Text;
 using Xunit;
 using Ydb.Sdk.Value;
@@ -470,4 +471,44 @@ public async Task Date_WhenSetDateOnly_ReturnDateTime()
         ydbCommand.Parameters.AddWithValue("dateOnly", DbType.Date, new DateOnly(2102, 2, 24));
         Assert.Equal(new DateTime(2102, 2, 24), await ydbCommand.ExecuteScalarAsync());
     }
+
+    [Theory]
+    [InlineData("12345", "12345.0000000000", 22, 9)]
+    [InlineData("54321", "54321", 5, 0)]
+    [InlineData("493235.4", "493235.40", 7, 2)]
+    [InlineData("123.46", "123.46", 5, 2)]
+    [InlineData("-184467434073.70911616", "-184467434073.7091161600", 35, 10)]
+    [InlineData("-18446744074", "-18446744074", 12, 0)]
+    [InlineData("-184467440730709551616", "-184467440730709551616", 21, 0)]
+    [InlineData("-218446744073.709551616", "-218446744073.7095516160", 22, 10)]
+    [InlineData(null, null, 22, 9)]
+    [InlineData(null, null, 35, 9)]
+    [InlineData(null, null, 35, 0)]
+    public async Task Decimal_WhenDecimalIsScaleAndPrecision_ReturnDecimal(string? value, string? expected,
+        byte precision, byte scale)
+    {
+        await using var ydbConnection = await CreateOpenConnectionAsync();
+        var decimalTableName = $"DecimalTable_{Random.Shared.Next()}";
+        var decimalValue = value == null ? (decimal?)null : decimal.Parse(value, CultureInfo.InvariantCulture);
+        var ydbCommand = new YdbCommand(ydbConnection)
+        {
+            CommandText = $"""
+                           CREATE TABLE {decimalTableName} (
+                                DecimalField Decimal({precision}, {scale}),
+                                PRIMARY KEY (DecimalField)
+                           )
+                           """
+        };
+        await ydbCommand.ExecuteNonQueryAsync();
+        ydbCommand.CommandText = $"INSERT INTO {decimalTableName}(DecimalField) VALUES (@DecimalField);";
+        ydbCommand.Parameters.Add(
+            new YdbParameter("DecimalField", DbType.Decimal, decimalValue)
+                { Precision = precision, Scale = scale });
+        await ydbCommand.ExecuteNonQueryAsync();
+
+        ydbCommand.CommandText = $"SELECT DecimalField FROM {decimalTableName}";
+        Assert.Equal(expected == null ? DBNull.Value : decimal.Parse(expected, CultureInfo.InvariantCulture),
+            await ydbCommand.ExecuteScalarAsync());
+        ydbCommand.CommandText = "DROP TABLE {decimalTableName};";
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -75,7 +75,7 @@ private static string ToYql(Type type) =>`
`75`	`75`	`type.TypeCase switch`
`76`	`76`	`{`
`77`	`77`	`Type.TypeOneofCase.TypeId => type.TypeId.ToString(),`
`78`		`- Type.TypeOneofCase.DecimalType => "Decimal(22, 9)",`
	`78`	`+ Type.TypeOneofCase.DecimalType => $"Decimal({type.DecimalType.Precision}, {type.DecimalType.Scale})",`
`79`	`79`	`Type.TypeOneofCase.OptionalType => $"{ToYql(type.OptionalType.Item)}?",`
`80`	`80`	`Type.TypeOneofCase.ListType => $"List<{ToYql(type.ListType.Item)}>",`
`81`	`81`	`Type.TypeOneofCase.VoidType => "Void",`