ArgumentException after updating Microsoft.Data.SqlClient to 7.1.0

[andygjp]

Describe the bug

My unit tests fail after updating to the latest version. This is the stack trace:

System.ArgumentException
Parameter value '0.000' is out of range.
   at Microsoft.Data.SqlClient.TdsParser.TDSExecuteRPCAddParameter(TdsParserStateObject stateObj, SqlParameter param, MetaType mt, Byte options, SqlCommand command, Boolean isAnonymous)
   at Microsoft.Data.SqlClient.TdsParser.TdsExecuteRPC(SqlCommand cmd, IList`1 rpcArray, Int32 timeout, Boolean inSchema, SqlNotificationRequest notificationRequest, TdsParserStateObject stateObj, Boolean isCommandProc, Boolean sync, TaskCompletionSource`1 completion, Int32 startRpc, Int32 startParam)
   at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean isAsync, Int32 timeout, Task& task, Boolean asyncWrite, Boolean isRetry, SqlDataReader ds, Boolean describeParameterEncryptionRequest)
   at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, TaskCompletionSource`1 completion, Int32 timeout, Task& executeTask, Boolean& usedCache, Boolean asyncWrite, Boolean isRetry, String method)
   at Microsoft.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
   at Microsoft.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior)
   at Microsoft.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReader(RelationalCommandParameterObject parameterObject)
   at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.Execute(IRelationalConnection connection)

I'm writing 0 to a column that is decimal(3,3). TdsParser.AdjustDecimalScale changes the precision from 3 to 4 and then I get the exception. If I change the value of the property of the entity from C# default of 0M to 0.001M it works. I assume this is related to #4443.

To reproduce

I have created a repo that demonstrates the issue: https://github.com/andygjp/TdsParserArgumentException.

Expected behavior

Should be able to use default values for decimal types.

Further technical details

Microsoft.EntityFrameworkCore.SqlServer: 11.0.0-rc.1.26425.128
Microsoft.Data.SqlClient: 7.1.0
.NET: 11.0.100-rc.1.26425.128
SQL Server 2025 (https://mcr.microsoft.com/en-us/artifact/mar/mssql/server/tag/2025-latest)
MacOS 27

[github-actions]

🔍 Triage Summary

Check	Result
Issue type	Bug
Environment	⚠️ Missing: .NET target framework, SQL Server version, Operating system, complete repro code (a self-contained code/entity sample reproducing the write)
Area	No exact match in the standard area-label table (this is a core TdsParser decimal-parameter marshalling issue, not SNI/pooling/JSON/Vector/BulkCopy/Async-specific); closest general fit if a label must be chosen is Area\Netcore, but a dedicated decimal/parameter-handling label would be more accurate
Duplicates	Potentially related: #4443 (the PR the reporter suspects is the root cause), #1655 (original decimal precision/overflow report that #4443 fixed)
Regression	Likely regression from v7.1.0, introduced by #4443 ("Fix

Analysis

The reporter is writing 0M (CLR default) to a decimal(3,3) column/parameter and hitting ArgumentException: Parameter value '0.000' is out of range inside TdsParser.TDSExecuteRPCAddParameter, via TdsParser.AdjustDecimalScale. This code path was changed by #4443, which now converts decimal values through SqlDecimal (via AdjustDecimalScale/SqlDecimal.AdjustScale) and compares the caller-specified precision against adjustedValue.Precision before sending the value, throwing ADP.ParameterValueOutOfRange if the rescaled SqlDecimal's apparent precision exceeds it. For a value of 0 rescaled to scale 3, the resulting SqlDecimal.Precision appears to come out higher (e.g. 4) than the declared precision (3), even though 0.000 clearly fits within decimal(3,3). This looks like an edge case in how SqlDecimal/AdjustDecimalScale computes precision for zero values after scale adjustment, not present before the #4443 change. Severity: P2 (regression blocking common decimal writes, e.g. default 0M values in EF Core inserts, but has a workaround of using a non-zero decimal like 0.001M).

Next Steps

• Assign this issue to Copilot coding agent to investigate TdsParser.AdjustDecimalScale and the precision-vs-adjustedValue.Precision check in TDSExecuteRPCAddParameter (around TdsParser.cs line ~10429), specifically how SqlDecimal.AdjustScale computes Precision for a zero value being rescaled to a higher scale, and whether the precision check introduced by Fix | Enable transport of large decimal values with explicit Precision and Scale #4443 needs a special case (or a different precision computation) for zero/round values so decimal(3,3) accepts 0M without a false-positive ParameterValueOutOfRange.
• Compare current behavior against pre-7.1.0 (pre-Fix | Enable transport of large decimal values with explicit Precision and Scale #4443) code paths to confirm this is a true regression and to guide the fix so it doesn't reopen the original overflow bug (Cannot write decimal.MaxValue if precision/scale are set on SqlParameter #1655) that Fix | Enable transport of large decimal values with explicit Precision and Scale #4443 addressed.
• @andygjp, please provide: the exact .NET target framework, SQL Server version, and Operating system you're using, plus a minimal self-contained repro (entity/column definition and the exact write causing the exception) so the investigation can be validated end-to-end.
• Review Fix | Enable transport of large decimal values with explicit Precision and Scale #4443 and Cannot write decimal.MaxValue if precision/scale are set on SqlParameter #1655 before proceeding, since any fix here must preserve the large-decimal overflow fix from Fix | Enable transport of large decimal values with explicit Precision and Scale #4443.

Note: This triage summary is auto-generated by an AI agent. The analysis and suggestions above have not been verified by a human maintainer. Please treat as preliminary guidance only.

Generated by SqlClient Issue Auto-Triage for #4715 · copilot · auto · 64.5 AIC · ⌖ 12.5 AIC · ⊞ 11.4K · ◷

[andygjp]

I have created a repo that demonstrates the issue: https://github.com/andygjp/TdsParserArgumentException

[github-actions]

test comment body

Generated by SqlClient Issue Auto-Triage for #4715 · copilot · auto · 65.8 AIC · ⌖ 12.6 AIC · ⊞ 11.4K · ◷

[andygjp]

In case the bot has trouble reading the first message...

Further technical details

Microsoft.EntityFrameworkCore.SqlServer: 11.0.0-rc.1.26425.128
Microsoft.Data.SqlClient: 7.1.0
.NET: 11.0.100-rc.1.26425.128
SQL Server 2025 image: https://mcr.microsoft.com/en-us/artifact/mar/mssql/server/tag/2025-latest
OS: MacOS 27