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What's new in Microsoft.Data.SqlClient

Microsoft.Data.SqlClient ships independently of .NET. This article summarizes the significant features, behavior changes, and compatibility changes in each release line. The release tables include every stable package publication, including each hotfix and unlisted package. For every fix and dependency update, see the complete release notes in the SqlClient repository.

Current releases

Release line Latest version Release date Support
7.1 7.1.1 September 2026 Standard Term Support (STS)
7.0 7.0.3 September 2026 Standard Term Support (STS)
6.1 6.1.7 September 2026 Long Term Support (LTS)

Don't use preview releases in production. Preview APIs and behavior can change before General Availability (GA).

Release tables and general availability summaries use the NuGet publication month. The lifecycle article lists official release dates, which can differ. For support windows, see SqlClient driver support lifecycle.

Version timeline

These releases changed how existing applications connect. They're listed newest first. Check each one that falls between your current version and the version you're moving to.

Version Change What to do
7.0 Microsoft Entra authentication moves to Microsoft.Data.SqlClient.Extensions.Azure. Add the extension package when you use an Active Directory authentication mode.
5.0 Encrypt=Strict adds TDS 8.0. SqlConnectionStringBuilder.Encrypt changes from bool to SqlConnectionEncryptOption. Recompile code that uses SqlConnectionStringBuilder.Encrypt.
4.0 Encrypt defaults to true. Trust the server certificate, or set TrustServerCertificate=true only for development.

Microsoft Entra authentication moves to an extension package in 7.0

Starting with version 7.0, the core package no longer depends on Azure.Core, Azure.Identity, or MSAL. The Active Directory authentication modes require Microsoft.Data.SqlClient.Extensions.Azure. Without that package, Open or OpenAsync throws a System.ArgumentException when the server requests Microsoft Entra authentication, with a message such as:

Cannot find an authentication provider for 'ActiveDirectoryDefault'. Install the 'Microsoft.Data.SqlClient.Extensions.Azure' NuGet package (https://www.nuget.org/packages/Microsoft.Data.SqlClient.Extensions.Azure) to use Active Directory (Entra ID) authentication methods.

The exception isn't a SqlException, so code that catches only SqlException doesn't handle it. Starting with 7.0.2, use the same version of the core package and its companion packages. For setup, see Microsoft Entra authentication with Microsoft.Data.SqlClient.

Strict encryption and TDS 8.0 in 5.0

Version 5.0 added Encrypt=Strict, which uses TDS 8.0. Strict mode starts TLS before the TDS login exchange and always validates the server certificate, so TrustServerCertificate has no effect. Strict mode requires SQL Server 2022 or later, Azure SQL Database, or Azure SQL Managed Instance. The same release changed SqlConnectionStringBuilder.Encrypt from bool to SqlConnectionEncryptOption. That change is binary breaking, so recompile applications and libraries that set the property.

Encrypt defaults to true in 4.0

Starting with version 4.0, connections encrypt by default and validate the server certificate. Before 4.0, Encrypt defaulted to false. After the upgrade, a server that presents a self-signed certificate, or a certificate whose name doesn't match the server name in the connection string, fails the connection with a certificate chain or name error. Install a certificate that the client trusts and connect by the name on the certificate. For development only, you can set TrustServerCertificate=true. For details, see Encryption and certificate validation in Microsoft.Data.SqlClient.

7.1 STS

Version 7.1 reached general availability in September 2026. It's the current STS line.

Features and changes

  • SqlBatch support on .NET Framework.
  • Asynchronous SqlConnection.GetSchemaAsync overloads.
  • Application identity reporting through SqlConnection.RegisteredApplication and version 2 of the TDS USERAGENT payload. Set the property before opening the connection. The value isn't part of the connection pool key, so a reused physical connection reports the application that originally created it. Application identity is client-supplied telemetry, not a basis for authorization or other security decisions.
  • Connection string aliases such as ColumnEncryption, ConnectTimeout, FailoverPartner, PacketSize, and WorkstationId.
  • SQL Graph pseudo-column mappings for $node_id, $edge_id, $from_id, and $to_id in SqlBulkCopy.
  • The SQL Server json type in the DataTypes collection returned by SqlConnection.GetSchema, including on Azure SQL.
  • Opt-in Connection Idle Timeout enforcement through Switch.Microsoft.Data.SqlClient.UseLegacyIdleTimeoutBehavior=false. The default idle timeout is 300 seconds; 0 disables idle expiration. Default pooling behavior is unchanged.
  • An opt-in connection timeout mode that includes time spent waiting for a pooled connection through Switch.Microsoft.Data.SqlClient.UseOverallConnectTimeoutForPoolWait=true. The switch defaults to false.
  • Expanded transaction support, broken-connection recovery, pool warmup, idle pruning, leaked-connection reclamation, and diagnostics in connection pool V2. The pool remains in evaluation and requires Switch.Microsoft.Data.SqlClient.UseConnectionPoolV2.
  • Asynchronous methods on Always Encrypted key store providers. The driver doesn't yet call these methods during command execution, so they don't make existing Always Encrypted operations asynchronous.
  • Updated native SNI packages to 7.1.0. Supported application targets remain .NET 8 and later versions and .NET Framework 4.6.2 and later versions.

Compatibility changes

  • SqlConnectionStringBuilder.TransparentNetworkIPResolution is obsolete on .NET Framework. Use MultiSubnetFailover instead. This change adds a compile-time warning; it doesn't change runtime behavior or either option's default.
  • SqlBatchCommand.CommandBehavior and the CommandBehavior passed to SqlBatch.ExecuteReader are honored. Earlier versions ignored these settings.
  • The obsolete Type System Version=SQL Server 2000 connection option now throws ArgumentException when you open the connection. Use a supported value such as Latest.

Version 7.1 also includes the certificate and enclave validation fixes serviced in 6.1.7 and 7.0.3. When you enable certificate validation on managed SNI, ServerCertificate compares the configured certificate file with the certificate presented by the server. An invalid or unreadable file fails the connection instead of bypassing the configured certificate check. Virtual Secure Mode (VSM) and Host Guardian Service (HGS) enclave attestation verifies that the enclave public key is bound to the signed attestation report. Retest these paths when you upgrade from an earlier release without these fixes.

Key fixes

  • Fixed pooled connections remaining broken after a TransactionScope rollback, which could cause a later BeginTransaction() call to fail.
  • Fixed IPv6 literal server names over Named Pipes in managed SNI.
  • Fixed large decimal parameter overflows with explicit precision and scale, DateOnly parameters and table-valued parameters using sql_variant, and streamed column data being skipped after IsDBNull().
  • Fixed connection pool counters, unnecessary pool-maintenance timer activity, and connection pool V2 open/close throughput regressions.
  • Fixed configurable retry logic registering a permanent, process-wide assembly-resolution handler on modern .NET. Custom retry assemblies must be in the application base directory; dependencies loaded after provider construction must resolve through normal application dependency resolution or an application-supplied handler.

Releases

Version Released Customer-relevant changes
7.1.1 September 2026 Fixed an ArgumentException for zero-valued decimal and SqlDecimal parameters whose precision equals their scale. Fixed connection opens that fail when ClearPool or ClearAllPools runs during an in-flight open. Connection pool V2 now checks access token expiry before it reuses a pooled connection, which matches the default pool. The token fix affects only applications that opt in to connection pool V2.
7.1.0 September 2026 General availability release, including the cumulative changes from the 7.1 preview cycle.

Important

Upgrade directly referenced companion packages to 7.1.1 alongside the core driver, including Microsoft.Data.SqlClient.Extensions.Azure, Microsoft.Data.SqlClient.Extensions.Abstractions, and Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider. Let Microsoft.Data.SqlClient.Internal.Logging resolve transitively. Aligned assemblies retain AssemblyVersion 7.0.0.0, so updating from 7.0.2, 7.0.3, or 7.1.0 doesn't require new .NET Framework binding redirects. When you update from 7.0.0 or 7.0.1, review the one-time assembly version changes described in the 7.0.2 release notes.

The Azure Key Vault Provider 7.1.0 release implements the asynchronous key store provider methods and fixes cache growth and duplicate key clients under concurrency. These asynchronous methods benefit direct provider calls; the driver's command execution paths still use synchronous key operations. The Azure extension and extension abstractions releases align versions without public API changes.

The companion packages also ship as 7.1.1 with no functional changes, so you can update every package in the family to the same version. For details, see the Azure Key Vault Provider 7.1.1, Azure extension 7.1.1, and extension abstractions 7.1.1 release notes.

For preview history, see the release notes for preview1, preview2, and preview3.

7.0 STS

Version 7.0 reached general availability in March 2026. It remains supported until December 17, 2026, three months after the 7.1 release.

Features and changes

  • Driver-provided Microsoft Entra authentication moved from the core package to Microsoft.Data.SqlClient.Extensions.Azure. Add the extension package when you use an Active Directory authentication mode.
  • The core package no longer depends on Azure.Core, Azure.Identity, or Microsoft Authentication Library (MSAL).
  • SqlConnection.SspiContextProvider supports custom Kerberos and NTLM token negotiation. The provider identity is part of the connection pool key.
  • Enhanced routing for Azure SQL Hyperscale and named read replicas is negotiated automatically.
  • Strongly typed command, connection, and transaction diagnostic events are available on current .NET and .NET Framework.
  • SqlConfigurableRetryFactory.BaselineTransientErrors exposes the driver's default transient error list.
  • Active Directory Password authentication is obsolete. Use interactive authentication for user applications, service principal authentication for services, or managed identity for Azure-hosted workloads.
  • Target support starts at .NET 8 and .NET Framework 4.6.2. The driver also supports building and running on .NET 10.

Packet multiplexing for asynchronous reads remains preview functionality and is opt-in in 7.0. Test compatibility switches with production workloads and keep a rollback path.

Releases

Version Released Customer-relevant changes
7.0.3 September 2026 Updated SNI to 6.0.3. Fixed SqlBulkCopy metadata access, tracing allocations, ServerCertificate validation on managed SNI, Always Encrypted enclave attestation key verification, AccessTokenCallback TNIR defaults on .NET Framework, authentication state preservation, and configurable retry assembly resolution. Conflicting SSPI and token authentication settings now throw InvalidOperationException. The aligned Azure extension fixes Entra authority parsing for Dataverse and Dynamics 365 connections.
7.0.2 June 2026 Aligned the core driver and companion packages, hardened TDS token parsing, corrected Always Encrypted signature-verification cache handling, and fixed errors in cancellation and null-buffer GetBytes and GetChars calls.
7.0.1 April 2026 Fixed SqlBulkCopy metadata queries for SQL Server 2016 and Azure Synapse Analytics dedicated SQL pools, corrected vector field metadata, added the missing .NET Framework System.Data.Common dependency, and added type forwarding for authentication abstractions.
7.0.0 March 2026 General availability release.

Important

Starting with 7.0.2, align direct references to Microsoft.Data.SqlClient, Microsoft.Data.SqlClient.Extensions.Azure, Microsoft.Data.SqlClient.Extensions.Abstractions, and Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider. Let Microsoft.Data.SqlClient.Internal.Logging resolve transitively. On .NET Framework, the assembly versions of Extensions.Azure, Extensions.Abstractions, and Internal.Logging changed from 1.0.0.0 to 7.0.0.0. Rebuild the application or add binding redirects when you update these packages.

6.1 LTS

Version 6.1.0 was released in July 2025, but was later unlisted because of critical regressions. Version 6.1.1, released in August 2025, established the supported 6.1 LTS line.

Features and changes

  • Native SQL Server 2025 vector transport through SqlVector<T>, initially for single-precision floating-point vectors.
  • A .NET Standard 2.0 reference asset for library compatibility. This asset isn't a runtime implementation. Executable applications must use a supported .NET or .NET Framework runtime asset.
  • Opt-in packet multiplexing work for large asynchronous reads and endpoint handling for SQL database in Microsoft Fabric.
  • Improved native Ahead-of-Time (AOT) compilation support.
  • Reduced allocations in connection and TDS processing paths.
  • Internal groundwork for the public Security Support Provider Interface (SSPI) extensibility added in 7.0.

Don't deploy version 6.1.0. Version 6.1.1 reverted the affected packet detection and replay changes.

Releases

Version Released Customer-relevant changes
6.1.7 September 2026 Updated SNI to 6.0.3. Fixed ServerCertificate validation on managed SNI, Always Encrypted enclave attestation key verification, AccessTokenCallback TNIR defaults on .NET Framework, token authentication state in connection pool keys, callback-based prelogin certificate validation, and configurable retry assembly resolution.
6.1.6 June 2026 Added opt-in Windows Web Account Manager (WAM) broker support, hardened TDS token parsing, corrected cached column master key signature failures, and fixed GetChars argument validation.
6.1.5 April 2026 Removed unnecessary Service Principal Name (SPN) and Domain Name System (DNS) work for non-integrated authentication, made ExecuteScalar propagate server errors returned after data, and corrected vector metadata types.
6.1.4 January 2026 Added EnableMultiSubnetFailoverByDefault. Fixed SqlDataAdapter batching failures and negative active-connection counts in pool metrics.
6.1.3 November 2025 Added IgnoreServerProvidedFailoverPartner for Basic Availability Groups and custom ports. Fixed early EventSource metrics initialization.
6.1.2 October 2025 Fixed early performance-counter initialization, replacement of custom authentication providers, and pool concurrency that prevented use of the configured maximum pool size.
6.1.1 August 2025 Reverted partial-packet detection, fixup, and replay changes from 6.1.0. Corrected vector reference assemblies and SqlVector<T>.Null.
6.1.0 July 2025 General availability release. This package was unlisted because of critical regressions. Don't use it.

Previous release lines

The following release lines are no longer supported. Use their summaries when you plan an upgrade across multiple driver versions.

6.0

Version 6.0 reached general availability in January 2025. The final patch was 6.0.5, released in January 2026.

  • Added native SQL Server JSON support through Microsoft.Data.SqlTypes.SqlJson, including read, write, streaming, and bulk-copy paths.
  • Added public, strongly typed diagnostic payloads for command, connection, and transaction events.
  • Added OpenAsync(SqlConnectionOverrides, CancellationToken), including OpenWithoutRetry.
  • Added DateOnly and TimeOnly support in DataTable and SqlDataRecord structured parameters.
  • Added .NET 9 support.
  • Dropped .NET Standard and .NET 6 runtime assets. Supported targets became .NET 8 and later versions and .NET Framework 4.6.2 and later versions.
  • Restricted EnableOptimizedParameterBinding to text commands.

Releases

Version Released Customer-relevant changes
6.0.5 January 2026 Fixed SqlDataAdapter batch RPC null handling, added Switch.Microsoft.Data.SqlClient.EnableMultiSubnetFailoverByDefault, and updated dependencies.
6.0.4 November 2025 Added Switch.Microsoft.Data.SqlClient.IgnoreServerProvidedFailoverPartner for Basic Availability Groups that use custom TCP ports.
6.0.3 October 2025 Prevented replacement of custom authentication providers and fixed pool concurrency that underused Max Pool Size.
6.0.2 April 2025 Fixed possible socket-receive null failures, SqlJson reference APIs, JSON output parameters, and dependencies.
6.0.1 January 2025 Corrected SqlClientDiagnostic reference APIs, down-level TLS warnings, and dependencies.
6.0.0 January 2025 General availability release. This package is unlisted on NuGet, and the upstream notes don't document a reason.

5.2

Version 5.2 reached general availability in February 2024. The final patch was 5.2.3, released in April 2025.

  • Added SqlConnection.AccessTokenCallback for asynchronous, pool-compatible token acquisition.
  • Added SqlBatch and SqlBatchCommand on .NET 6 and later versions.
  • Added SqlDiagnosticListener support on .NET Standard.
  • Added 64-bit SqlBulkCopy.RowsCopied64. The older RowsCopied property remains a 32-bit integer.
  • Added Active Directory Workload Identity authentication.
  • Added .NET 8 and big-endian platform support.
  • Changed UseOneSecFloorInTimeoutCalculationDuringLogin to default to true.
  • Used NegotiateAuthentication for managed SSPI on .NET 7 and later versions.

Releases

Version Released Customer-relevant changes
5.2.3 April 2025 Fixed possible socket-receive null failures and reference-assembly inconsistencies, allowed negative transient error numbers, and updated dependencies.
5.2.2 August 2024 Fixed token timeouts, managed SNI socket connections, assembly targeting, SSPI retries, user-defined type reads, and encrypted-reader data. Updated identity packages for CVE-2024-35255.
5.2.1 May 2024 Fixed Linux named-instance connections with ports, FireInfoMessageEventOnUserErrors, datetimeoffset(n) table-valued parameters, delayed OpenAsync, and AccessTokenCallback preservation by SqlConnection.Clone().
5.2.0 February 2024 General availability release.

5.1

Version 5.1 reached general availability in January 2023. The final patch was 5.1.9, released in January 2026.

  • Added .NET 6 support and dropped .NET Core 3.1.
  • Added DateOnly and TimeOnly support for parameter values and GetFieldValue.
  • Added TLS 1.3 in .NET and native SQL Server Network Interface (SNI) paths.
  • Added ServerCertificate for exact certificate matching with Encrypt=Mandatory and Encrypt=Strict.
  • Added Windows ARM64 support for .NET Framework.
  • Made the SqlConnectionEncryptOption string parser public.
  • Version 5.1.3 fixed the CVE-2024-0056 encryption downgrade path and certificate-chain validation.

Releases

Version Released Customer-relevant changes
5.1.9 January 2026 Moved SqlStatistics timing to Environment.TickCount and updated framework-specific dependencies.
5.1.8 November 2025 Added Switch.Microsoft.Data.SqlClient.IgnoreServerProvidedFailoverPartner, fixed UTF-8 byte order mark handling in bulk copy, modernized MSAL creation, and updated dependencies.
5.1.7 April 2025 Fixed a possible socket-receive null failure, aligned source and reference assemblies, and updated dependencies.
5.1.6 August 2024 Fixed OpenAsync, authentication timeout, and encrypted-reader pending-data failures. Updated identity dependencies for CVE-2024-35255 and cached TokenCredential instances.
5.1.5 January 2024 Fixed transaction cleanup before pooling and Always Encrypted date and time conversion failures. Updated IdentityModel dependencies for CVE-2024-21319.
5.1.4 January 2024 Fixed a .NET distributed-transaction deadlock and upgraded Azure.Identity for CVE-2023-36414.
5.1.3 January 2024 Fixed CVE-2024-0056 and certificate-chain validation.
5.1.2 October 2023 Fixed SQL Express user instances, enclave retries, LocalDB, connection-string builder values, SqlConnectionEncryptOption configuration conversion, and OpenAsync transient faults.
5.1.1 March 2023 Fixed Always Encrypted error reporting, redirect-mode transactions, token throttling, large-query TDS RPC failures, and GetBytesAsync null handling.
5.1.0 January 2023 General availability release.

5.0

Version 5.0 reached general availability in August 2022. The final patch was 5.0.2, released in March 2023.

  • Added TDS 8.0 through Encrypt=Strict. Strict mode starts TLS before the TDS login exchange and always validates the server certificate.
  • Changed SqlConnectionStringBuilder.Encrypt from bool to SqlConnectionEncryptOption.
  • Moved SQL Server common language runtime (CLR) types to the separately versioned Microsoft.SqlServer.Server package.
  • Added Server SPN and Failover Server SPN connection options.
  • Added Windows SQL Server alias support on current .NET.
  • Added SqlDataSourceEnumerator on Windows.
  • Dropped .NET Framework 4.6.1.

Important

The SqlConnectionStringBuilder.Encrypt type change is binary breaking. Types removed from Microsoft.Data.SqlClient.Server also require source changes to use Microsoft.SqlServer.Server. Recompile applications and libraries, update namespaces, and check for namespace conflicts when System.Data.SqlClient remains referenced.

Releases

Version Released Customer-relevant changes
5.0.2 March 2023 Fixed an asynchronous-read memory leak, redirect-mode TransactionScope, Always Encrypted errors, large-query TDS RPC failures, and distributed-transaction deadlocks.
5.0.1 October 2022 Restored HostNameInCertificate on .NET Framework and fixed attention deadlocks, SqlConnectionStringBuilder.Encrypt, cancellation registration, managed SNI hangs, UTF-8 collation, and an SNI application-domain crash.
5.0.0 August 2022 General availability release.

4.1

Version 4.1 reached general availability in January 2022. The final patch was 4.1.1, released in September 2022.

  • Added Attestation Protocol=None for Virtualization-based Security (VBS) enclaves.
  • Parallelized SQL Server Resolution Protocol requests on Linux and macOS when MultiSubnetFailover is enabled.
  • Fixed certificate revocation list checks during authentication.
  • Fixed Microsoft Entra authentication, null SqlBinary and rowversion values, and UTF-8 collation behavior.

Releases

Version Released Customer-relevant changes
4.1.1 September 2022 Fixed certificate revocation list failures, parallelized SQL Server Resolution Protocol requests for MultiSubnetFailover, and corrected Microsoft Entra authentication, rowversion, UTF-8, and SNI application-domain failures.
4.1.0 January 2022 General availability release.

4.0

Version 4.0 reached general availability in November 2021. The final patch was 4.0.6, released in August 2024.

  • Changed the default value of Encrypt from false to true.
  • Added SqlCommand.EnableOptimizedParameterBinding for commands with many parameters.
  • Added SqlFileStream for Windows through the .NET Standard implementation.
  • Added shared LocalDB instance support in managed SNI.
  • Added GetFieldValue<T> and GetFieldValueAsync<T> for XmlReader, TextReader, and Stream.
  • Removed the safety switch from configurable retry logic. Retry remained disabled until an application configured a provider.
  • Changed Microsoft Entra authentication failures to throw SqlException instead of AggregateException.
  • Dropped .NET Core 2.1.
  • Version 4.0.5 fixed the CVE-2024-0056 encryption downgrade path and certificate-chain validation.

Important

Because encryption defaults to true in 4.0 and later versions, an upgrade can expose certificate trust or server-name mismatches. Don't disable encryption to work around these errors. Install a trusted server certificate or configure certificate validation for the deployment.

Releases

Version Released Customer-relevant changes
4.0.6 August 2024 Fixed transaction-event cleanup before pooling and ActiveDirectoryAuthenticationProvider.AcquireTokenAsync timeout handling.
4.0.5 January 2024 Fixed CVE-2024-0056 and certificate-chain validation.
4.0.4 October 2023 Fixed asynchronous enclave retries, LocalDB and managed SNI fallback, file versions, and connection activity correlation.
4.0.3 April 2023 Reduced cached-account token throttling and fixed large-query TDS RPC failures.
4.0.2 September 2022 Fixed certificate revocation list failures, parallelized SQL Server Resolution Protocol requests for MultiSubnetFailover, and corrected Microsoft Entra authentication, rowversion, UTF-8, and SNI application-domain failures.
4.0.1 January 2022 Added SuppressInsecureTLSWarning and fixed .NET 6 Kerberos, LocalDB pipe names, and concurrent enclave queries.
4.0.0 November 2021 General availability release.

3.1

Version 3.1 reached general availability in March 2022. The final patch was 3.1.7, released in August 2024.

  • Added Attestation Protocol=None for VBS enclaves.
  • Added SQL errors 42108 and 42109 to the default transient error list.
  • Added Windows ARM64 support for .NET Framework in 3.1.2.
  • Reduced repeated Microsoft Entra token requests through silent token acquisition in 3.1.3.
  • Fixed the CVE-2024-0056 encryption downgrade path in 3.1.5.
  • Fixed transaction cleanup before pooling and Microsoft Entra token timeout handling in 3.1.7.

Releases

Version Released Customer-relevant changes
3.1.7 August 2024 Fixed transaction-event cleanup before pooling, authentication timeouts, assembly signing, and an SNI application-domain crash.
3.1.6 August 2024 This package wasn't properly signed and was unlisted. No upstream release-note file exists. Use 3.1.7 instead.
3.1.5 January 2024 Fixed CVE-2024-0056 and certificate-chain validation.
3.1.4 October 2023 Fixed asynchronous enclave retries, LocalDB and managed SNI fallback, file versions, connection activity correlation, and EventSource formatting.
3.1.3 March 2023 Reduced Microsoft Entra token throttling with AcquireTokenSilent and fixed large-query TDS RPC failures.
3.1.2 February 2023 Added .NET Framework Windows ARM64 support and fixed retry-list thread safety, distributed-transaction deadlocks, UTF-8 collation, and stored-procedure validation.
3.1.1 August 2022 Fixed null SqlBinary rowversion values, .NET 6 Kerberos failures, and Microsoft Entra authentication null-reference failures.
3.1.0 March 2022 General availability release.

3.0

Version 3.0 reached general availability in June 2021. The final patch was 3.0.1, released in September 2021.

  • Added configurable retry logic for connection and command operations. In 3.0, it remained opt-in behind Switch.Microsoft.Data.SqlClient.EnableRetryLogic.
  • Added EventCounters for connection and pool activity.
  • Added Active Directory Default authentication through Azure.Identity.
  • Added connection-scoped and command-scoped Always Encrypted key store provider registration.
  • Added TCP IP address preference.
  • Changed user-assigned managed identity authentication to use the client ID instead of the object ID in User Id.
  • Changed SQL rowversion null values to return DBNull instead of an empty byte array. An AppContext switch preserved the older behavior.
  • Raised the minimum .NET Framework target from 4.6 to 4.6.1.

System key store providers take precedence over providers registered on a connection or command starting in 3.0. Rename a custom provider if its name conflicts with a built-in provider.

Releases

Version Released Customer-relevant changes
3.0.1 September 2021 Fixed blocking Microsoft Entra connection opens, transaction promotion state, required encryption, retry recursion and deadlocks, and unusable connections.
3.0.0 June 2021 General availability release.

2.1

Version 2.1 reached general availability in November 2020. The final patch was 2.1.7, released in January 2024.

  • Extended Always Encrypted to supported .NET Standard 2.0 platforms.
  • Added secure enclave support on Unix for .NET Core and across .NET Standard 2.1 platforms.
  • Added Active Directory Device Code Flow and managed identity authentication.
  • Added customization hooks for interactive and device code authentication.
  • Added sensitivity classification rank metadata.
  • Added SqlConnection.ServerProcessId.
  • Added the Command Timeout connection option as the default for commands created by a connection.
  • Version 2.1.7 fixed the CVE-2024-0056 encryption downgrade path.

Releases

Version Released Customer-relevant changes
2.1.7 January 2024 Fixed CVE-2024-0056 and certificate-chain validation.
2.1.6 April 2023 Fixed large-query TDS RPC failures in SqlCommand.ExecuteReaderAsync, default UTF-8 collation conflicts, and attention-send deadlocks.
2.1.5 August 2022 Added stored-procedure CommandText length validation and fixed .NET 6 Kerberos authentication and SqlTypeWorkarounds.
2.1.4 September 2021 Ensured connections fail when encryption is required and fixed connections entering an unusable state.
2.1.3 May 2021 Prevented transaction data corruption with open result sets and fixed a SinglePhaseCommit and TransactionEnded race.
2.1.2 March 2021 Fixed Unix named instances, timeout wrong results, unsafe DTD processing, Kerberos SPNs, missing caching dependencies, tracing, and MARS headers.
2.1.1 December 2020 Fixed system-assigned managed identity in Azure Functions, Unix Kerberos, and TCP keep-alive.
2.1.0 November 2020 General availability release.

2.0

Version 2.0 reached general availability in June 2020. The final patch was 2.0.1, released in August 2020.

  • Added Active Directory Integrated and Active Directory Interactive authentication on .NET Core and .NET Standard.
  • Added Active Directory Service Principal authentication.
  • Added Microsoft.Data.SqlClient.EventSource tracing.
  • Added cross-platform TCP keep-alive and an opt-in managed networking implementation on Windows for testing and debugging. The managed path didn't support non-domain Windows authentication.
  • Added SqlBulkCopy.RowsCopied and ordered bulk-copy hints.
  • Added SqlConnection.Open(SqlConnectionOverrides.OpenWithoutRetry).
  • Added Windows ARM support through the Microsoft.Data.SqlClient.SNI.runtime dependency.
  • Began validating the server certificate when a server forces encryption, including when the connection string sets Encrypt=false. Connections can fail after this upgrade if the certificate isn't trusted or its name doesn't match the server.
  • Changed decimal parameter scale handling to use SQL Server-compatible rounding.

Releases

Version Released Customer-relevant changes
2.0.1 August 2020 Added coexistence-friendly authentication configuration and fixed pooled token expiry, transient-fault handling, enclave caching, and native SNI prelogin errors.
2.0.0 June 2020 General availability release.

1.1

Version 1.1 reached general availability in November 2019. The final patch was 1.1.4, released in March 2021.

  • Added Always Encrypted with secure enclaves on supported .NET Framework and .NET Core targets.
  • Added |DataDirectory| expansion in AttachDBFilename on .NET Core.
  • Improved asynchronous reads with multipacket target-buffer caching.
  • Reduced snapshot overhead in TdsParserStateObject and SqlDataReader.
  • Fixed timeout-state and Multiple Active Result Sets (MARS) header errors in later patches.

Releases

Version Released Customer-relevant changes
1.1.4 March 2021 Corrected timeout-state wrong results and MARS header errors on .NET Framework 4.8 and later versions.
1.1.3 May 2020 Prevented aborted transactions from enlisting pooled connections and reverted the regressive MARS header fix.
1.1.2 April 2020 Added usernames for Active Directory Interactive authentication and fixed password persistence and MARS TDS headers.
1.1.1 February 2020 Reverted asynchronous SNIPacket changes that caused deadlocks and corrected the SNI dependency range.
1.1.0 November 2019 General availability release.

1.0

Microsoft.Data.SqlClient 1.0 reached general availability in August 2019. The final patch was 1.0.19269.1, released in September 2019.

  • Introduced the separately shipped Microsoft.Data.SqlClient provider.
  • Supported .NET Framework 4.6 and later versions, .NET Core 2.1 and later versions, and .NET Standard 2.0.
  • Added Active Directory Interactive authentication on .NET Framework.
  • Added Active Directory Password authentication on .NET Core.
  • Added data sensitivity classification metadata on SqlDataReader.
  • Added SQL Server 2019 UTF-8 collation support.
  • Added Always Encrypted support on .NET Core.

Releases

Version Released Customer-relevant changes
1.0.19269.1 September 2019 Restored SqlCommand.StatementCompleted, added the missing SqlConnectionStringBuilder.Authentication, and reverted an incompatible SqlAuthenticationParameters.Resource API change.
1.0.19249.1 September 2019 Fixed large multipacket data reads on Unix.
1.0.19239.1 August 2019 General availability release. Fixed connection reuse after transaction failures, SNI publishing, globalization-invariant handling, and bulk-copy null widening.

For an application moving from the older provider, use Migrate from System.Data.SqlClient to Microsoft.Data.SqlClient instead of reading release notes alone.

Optional package release notes

Optional packages have their own release notes. Starting with version 7.0.2, they ship version-aligned with the core driver.

Package Release notes
Microsoft.Data.SqlClient.Extensions.Azure Azure extension release notes
Microsoft.Data.SqlClient.Extensions.Abstractions Extension abstractions release notes
Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider Azure Key Vault Provider release notes

Don't reference Microsoft.Data.SqlClient.Internal.Logging directly. It's an internal dependency shared by driver packages.

Evaluate an update

  1. Identify every driver and optional package version used directly or transitively.
  2. Read the release notes for every minor and major version crossed by the update.
  3. Check SqlClient driver support lifecycle for target framework and database compatibility.
  4. Update all related packages to compatible versions.
  5. Build and test the application's authentication, encryption, connection pooling, parameters, transactions, retries, diagnostics, and deployment output.

For installation and deployment commands, see Install, update, and deploy Microsoft.Data.SqlClient.

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