Add DECIMAL Type Support to C# Language Extension #83
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| Original file line number | Diff line number | Diff line change |
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@@ -9,12 +9,14 @@ | |
| // | ||
| //********************************************************************* | ||
| using System; | ||
| using System.Data.SqlTypes; | ||
| using System.Linq; | ||
| using System.Text; | ||
| using System.Runtime.InteropServices; | ||
| using System.Collections.Generic; | ||
| using Microsoft.Data.Analysis; | ||
| using static Microsoft.SqlServer.CSharpExtension.Sql; | ||
| using static Microsoft.SqlServer.CSharpExtension.SqlNumericHelper; | ||
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| namespace Microsoft.SqlServer.CSharpExtension | ||
| { | ||
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@@ -174,6 +176,9 @@ DataFrameColumn column | |
| case SqlDataType.DotNetDouble: | ||
| SetDataPtrs<double>(columnNumber, GetArray<double>(column)); | ||
| break; | ||
| case SqlDataType.DotNetNumeric: | ||
| ExtractNumericColumn(columnNumber, column); | ||
| break; | ||
| case SqlDataType.DotNetChar: | ||
| // Calculate column size from actual data. | ||
| // columnSize = max UTF-8 byte length across all rows. | ||
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@@ -203,7 +208,7 @@ DataFrameColumn column | |
| /// <summary> | ||
| /// This method sets data pointer for the column and append the array to the handle list. | ||
| /// </summary> | ||
| private void SetDataPtrs<T>( | ||
|
Contributor
There was a problem hiding this comment. The change from
Contributor
Author
There was a problem hiding this comment. it's intentional; I've been trying to get rid of unsafe as much as possible. I may revert it though to keep the change focused. |
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| ushort columnNumber, | ||
| T[] array | ||
| ) where T : unmanaged | ||
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@@ -213,6 +218,68 @@ T[] array | |
| _handleList.Add(handle); | ||
| } | ||
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| /// <summary> | ||
| /// Extracts NUMERIC/DECIMAL column data by converting SqlDecimal values to ODBC-compatible SQL_NUMERIC_STRUCT array. | ||
| /// </summary> | ||
| /// <param name="columnNumber">The column index.</param> | ||
| /// <param name="column">The DataFrameColumn containing SqlDecimal values.</param> | ||
| private unsafe void ExtractNumericColumn( | ||
| ushort columnNumber, | ||
| DataFrameColumn column) | ||
| { | ||
| if (column == null) | ||
| { | ||
| SetDataPtrs<SqlNumericStruct>(columnNumber, Array.Empty<SqlNumericStruct>()); | ||
| return; | ||
| } | ||
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| // Determine target precision/scale from max values across all rows | ||
| // | ||
| byte precision = SqlNumericHelper.SQL_MIN_PRECISION; | ||
| byte scale = (byte)_columns[columnNumber].DecimalDigits; | ||
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| for (int rowNumber = 0; rowNumber < column.Length; ++rowNumber) | ||
| { | ||
| if (column[rowNumber] != null) | ||
| { | ||
| SqlDecimal value = (SqlDecimal)column[rowNumber]; | ||
| if (!value.IsNull) | ||
| { | ||
| scale = Math.Max(scale, value.Scale); | ||
| precision = Math.Max(precision, value.Precision); | ||
| } | ||
| } | ||
| } | ||
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| // Enforce T-SQL DECIMAL(p,s) constraints: 1 <= p <= 38, 0 <= s <= p | ||
| // | ||
| precision = Math.Max(precision, SqlNumericHelper.SQL_MIN_PRECISION); | ||
| precision = Math.Min(precision, SqlNumericHelper.SQL_MAX_PRECISION); | ||
| if (scale > precision) | ||
| { | ||
| precision = scale; | ||
| } | ||
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There was a problem hiding this comment. ExtractNumericColumn derives target precision as max(value.Precision) and target scale as max(value.Scale) independently. If a column contains values with different scales, increasing the chosen scale can require a larger precision for values with large integer parts (e.g., 123 + scale 2 => 123.00 needs precision 5), which will make FromSqlDecimal throw on conversion. Consider computing targetPrecision as max((value.Precision - value.Scale) + targetScale) across non-null values (where targetScale is the chosen max scale), so all values remain representable after scale normalization.
Contributor
There was a problem hiding this comment. +1 — this is a real bug, not just a nit. The independent Concrete scenario: value This will hit production any time a user's C# executor returns a |
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| // Update metadata: Size = precision (total digits), DecimalDigits = scale (fractional digits) | ||
| // | ||
| _columns[columnNumber].Size = precision; | ||
| _columns[columnNumber].DecimalDigits = scale; | ||
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| Logging.Trace($"ExtractNumericColumn: Column {columnNumber}, T-SQL type=DECIMAL({precision},{scale}), RowCount={column.Length}"); | ||
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| // Convert all values (including NULLs) to SQL_NUMERIC_STRUCT using FromSqlDecimal | ||
| // | ||
| SqlNumericStruct[] numericArray = new SqlNumericStruct[column.Length]; | ||
| for (int rowNumber = 0; rowNumber < column.Length; ++rowNumber) | ||
| { | ||
| SqlDecimal value = (column[rowNumber] != null) ? (SqlDecimal)column[rowNumber] : SqlDecimal.Null; | ||
| numericArray[rowNumber] = FromSqlDecimal(value, precision, scale); | ||
| Logging.Trace($"ExtractNumericColumn: Row {rowNumber}, Value={value}"); | ||
| } | ||
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| SetDataPtrs<SqlNumericStruct>(columnNumber, numericArray); | ||
| } | ||
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| /// <summary> | ||
| /// This method gets the array from a DataFrameColumn Column for numeric types. | ||
| /// </summary> | ||
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The change from
private unsafe void SetDataPtrs<T>toprivate void SetDataPtrs<T>is technically correct (the method body usesGCHandlewhich doesn't needunsafe), but it's unrelated to the DECIMAL feature. If it's intentional cleanup, call it out in the PR description. Otherwise, revert to keep the diff focused.