This update brings the following changes over the previous release:

Added

• Added packet multiplexing support to improve large data read performance. #2714 #3161 #3202
• Added support for special casing with Fabric endpoints. #3084

Fixed

• Fixed distributed transactions to be preserved during pooled connection resets. #3019.
• Fixed application crash when the Data Source parameter begins with a comma. #3250.
• Resolved synonym count discrepancies in debug mode. #3098.
• Addressed warnings for down-level SSL/TLS versions. #3126.

Changed

• Optimized binary size for AOT. #3091
• Refined bulk copy operations to handle unmatched column names more effectively. #3205.
• Enhanced SqlBulkCopy to explicitly identify mismatched column names. #3183.
• Optimized outgoing SSPI blob handling using IBufferWriter<byte>. #2452.
• Replaced byte[] with string for SNI to improve efficiency. #2790.
• Code cleanup to remove SQL 2000 support #2839, #3206, #3217,
• Connection pool design refactor for a modular connection pool design #3199
• Updated various dependencies #3229, primarily:
  • System.Text.Encodings.Web to v8.0.0
  • System.Text.Json to v8.0.5
  • Azure.Identity to v1.13.2
  • Microsoft.Identity.Model.Json.Web.Tokens to v7.7.1
  • Microsoft.Identity.Model.Protocols.OpenIdConnect to v7.7.1
• Code merge towards a unified SqlClient project, aligning .NET Framework and .NET Core implementations. (#2957, #2963, #2984, #2982, #3023, #3015, #2967, #3164, #3163, #3171, #3182, #3179, #3156, #3213, #3232, #3236, #3231, #3241, #3246, #3247, #3222, #3255, #3254, #3259, #3264, #3256, #3251, #3275, #3277, #3263, #3292, #3208).
• Test improvements include updates to test references, removal of hardcoded certificates, improved stability, and better coverage (#3041, #3034, #3130, #3128, #3181, #3060, #3184, #3033, #3186, #3025, #3230, #3237, #3059, #3061).

New Contributors

• @emmanuel-ferdman made their first contribution in #3041
• @MaceWindu made their first contribution in #3134
• @JNjenga made their first contribution in #3183
• @Midhunnnk made their first contribution in #3250

This update brings the following changes since the 5.2.2 release:

Fixed

• Fixed possible NullPointerException during socket receive (PR #3284)
• Fixed inconsistencies between source and reference projects (PR #3124)
• Adjusted retry logic to allow errors with negative numbers to be considered transient (PR #3185)

Changed

• Updated the following dependencies:
  • System.Private.Uri 4.3.2 - Avoid transitive CVE-2019-0820 (PR #3076)
  • Microsoft.Extensions.Caching.Memory 6.0.1 to 6.0.3 - Avoid CVE-2024-43483 (PR #3280)

This update brings the following changes since the 5.1.6 release:

Fixed

• Fixed possible NullPointerException during socket receive (PR #3285)
• Fixed inconsistencies between source and reference projects (PR #3180)

Changed

• Updated the following dependencies:
  • Microsoft.Data.SqlClient.SNI 5.1.1 to 5.1.2 for .NET Framework on Windows (PR #3294)
  • Microsoft.Data.SqlClient.SNI.runtime 5.1.1 to 5.1.2 for .NET on Windows (PR #3294)
  • Microsoft.Extensions.Caching.Memory 6.0.1 to 6.0.3 - Avoid CVE-2024-43483 (PR #3068)
  • Microsoft.Extensions.Hosting 6.0.0 to 6.0.1 - Avoid transitive dependency on vulnerable System.Text.Json 6.0.0 (PR #3207)
  • System.Private.Uri 4.3.2 - Avoid transitive CVE-2019-0820 (PR #3077)
  • System.Text.Encodings.Web 6.0.0 to 6.0.1 - Avoid transitive downgrade for .NET Framework targets (PR #3279)
  • System.Text.Json 6.0.11 - Avoid transitive dependencies on older vulnerable versions for .NET Framework targets (PR #3279)

This update brings the below changes over the previous release:

Fixed

• Fixed possible NullPointerException during socket receive #3283
• Fixed reference assembly definitions for SqlJson APIs #3169
• Fixed an error reading the output parameter of type JSON while executing stored procedure #3173

Changed

• Updated the below dependencies:
  • Updated Microsoft.Bcl.Cryptography from 9.0.0 to 9.0.4 for .NET 9 targeted dll. #3281
  • Updated Microsoft.Extensions.Caching.Memory from 9.0.0 to 9.0.4 for .NET 9 targeted dll. #3281
  • Updated System.Configuration.ConfigurationManager from 9.0.0 to 9.0.4 for .NET 9 targeted dll. #3281
  • Updated System.Security.Cryptography.Pkcs from 9.0.0 to 9.0.4 for .NET 9 targeted dll. #3281

Released to NuGet.org on 2025-01-23

Breaking Changes

• Removed support for .NET Standard. #2386
• Removed support for .NET 6 #2927
• Removed UWP (UAP) references. #2483
• Removed SQL 2000 client-side debugging support for .NET Framework #2981, #2940

Added

JSON Support

JSON data type support is now available in Microsoft.Data.SqlClient v6.0. This release introduces SqlJson type available as an extension to System.Data.SqlDbTypes:

using System;
using System.Data.SqlTypes;
using System.Text.Json;

namespace Microsoft.Data.SqlTypes
{
    /// <summary>
    /// Represents the JSON data type in SQL Server.
    /// </summary>
    public class SqlJson : INullable
    {
        /// <summary>
        /// Parameterless constructor. Initializes a new instance of the SqlJson class which 
        /// represents a null JSON value.
        /// </summary>
        public SqlJson() { }

        /// <summary>
        /// Takes a <see cref="string"/> as input and initializes a new instance of the SqlJson class.
        /// </summary>
        /// <param name="jsonString"></param>
        public SqlJson(string jsonString) { }

        /// <summary>
        /// Takes a <see cref="JsonDocument"/> as input and initializes a new instance of the SqlJson class.
        /// </summary>
        /// <param name="jsonDoc"></param>
        public SqlJson(JsonDocument jsonDoc) { }

        /// <inheritdoc/>
        public bool IsNull => throw null;

        /// <summary>
        /// Represents a null instance of the <see cref="SqlJson"/> type.
        /// </summary>
        public static SqlJson Null { get { throw null; } }

        /// <summary>
        /// Gets the string representation of the Json content of this <see cref="SqlJson" /> instance.
        /// </summary>
        public string Value { get ; }
    }
}

The JSON data type supports reading, writing, streaming, and performing bulk copy operations.

Introducing SqlClientDiagnostics

SqlClientDiagnostic is now available as a strongly-typed collection of key-value pairs that can be captured by consuming applications.

// Class that provides strongly-typed collection of key-value pairs for SqlClient diagnostic objects.
public abstract class SqlClientDiagnostic : System.Collections.Generic.IReadOnlyList<System.Collections.Generic.KeyValuePair<string, object>>
{
    // A guid value used to correlate before, after and error events.
    public System.Guid OperationId;
    
    // The name of the operation.
    public string Operation;

    // The timestamp of the event.
    public long Timestamp;

    // The number of elements in the collection.
    public int Count;

    // The element at the specified index in the read-only list.
    public System.Collections.Generic.KeyValuePair<string, object> this[int index];
    
    // An enumerator that can be used to iterate through the collection.
    public System.Collections.Generic.IEnumerator<System.Collections.Generic.KeyValuePair<string, object>> GetEnumerator();
}

Added Support for Connection Overrides in OpenAsync() API

The default behavior of SqlConnection.OpenAsync() can be overridden to disable the ten-second delay and automatic connection retries triggered by transient errors.

using(SqlConnection sqlConnection = new SqlConnection("Data Source=(local);Integrated Security=true;Initial Catalog=AdventureWorks;"))
{
    await sqlConnection.OpenAsync(SqlConnectionOverrides.OpenWithoutRetry, cancellationToken);
}

Other Additions

• Added support for .NET 9 #2946
• Added localization in Czech, Polish, and Turkish #2987
• Added TokenCredential object to take advantage of token caching in ActiveDirectoryAuthenticationProvider. #2380
• Added support for using DateOnly and TimeOnly in DataTable and SqlDataRecord structured parameters. #2258
• Added scope trace for GenerateSspiClientContext. #2497, #2725
• Added readme to NuGet package #2826
• Enabled NuGet package auditing via NuGet.org audit source #3024
• Added missing SqlCommand_BeginExecuteReader code sample #3009

Fixed

• Fixed Socket.Connect timeout issue caused by thread starvation. #2777
• Fixed pending data with SqlDataReader against an encrypted column. #2618
• Fixed Entra authentication when using infinite connection timeout in ActiveDirectoryAuthenticationProvider. #2651
• Fixed GetSchema by excluding unsupported engines due to lack of support for ASSEMBLYPROPERTY function. #2593
• Fixed SSPI retry negotiation with default port in .NET. #2559
• Fixed assembly path in .NET 8.0 and .AssemblyAttributes. #2550
• Fixed certificate chain validation. #2487
• Fixed clone of SqlConnection to include AccessTokenCallback. #2525
• Fixed issue with DateTimeOffset in table-valued parameters, which was introduced in 5.2. #2453
• Fixed ArgumentNullException on SqlDataRecord.GetValue when using user-defined data type on .NET. #2448
• Fixed SqlBuffer and SqlGuid when it's null. #2310
• Fixed SqlBulkCopy.WriteToServer state in a consecutive calls. #2375
• Fixed null reference exception with SqlConnection.FireInfoMessageEventOnUserErrors after introducing the batch command. #2399
• Fixed scale serialization when explicitly set to 0 #2411
• Fixed issue blocking GetSchema commands from being enrolled into the current transaction #2876
• Adjusted retry logic to allow errors with negative numbers to be considered transient #2896
• Fixed string formatting in OutOfMemory exceptions #2797
• Increased routing attempts to 10 in netcore for LoginNoFailover and added routing support to LoginWithFailover to standardize routing behavior between netcore and netfx #2873
• Restructured documentation into XML format so that it displays correctly in Visual Studio #2836, #2822, #2834, #2851, #2863, #2864, #2865, #2869, #2871, #2837, #2821
• Fixed cleanup behavior when column decryption fails. Prevents leaving stale data on the wire for pooled connections #2843, #2825
• Reverted default value of UseMinimumLoginTimeout context switch to 'true' #2419
• Added missing DynamicallyAccessedMembers attributes in .NET Runtime reference assemblies. #2946
• Synchronized dependencies of reference assemblies with runtime assemblies #2878
• Fixed lazy initialization of the _SqlMetaData hidden column map for .NET Framework #2964
• Fixed reference assembly definitions for SqlClientDiagnostic APIs #3097
• Fixed issue with down-level SSL/TLS version warnings #3126

Changed

• Dependency changes
  • Added dependency on Microsoft.Bcl.Cryptography:9.0.0 #2946
  • Added dependency on System.Security.Cryptography.Pkcs:9.0.0 to address SYSLIB0057#2946
  • Added dependency on System.Text.Json 8.0.5 for .NET 8+ and 6.0.10 for other versions #2921
  • Removed dependency on Microsoft.Extensions.Caching.Memory and System.Security.Cryptography.Cng, which were unnecessary after removing .NET Standard. #2577
  • Removed dependency on System.Text.Json from .NET 8+ #2930
    ...

Breaking Changes

• Dropped support for .NET 6 #2927
• Removed SQL 2000 client-side debugging support for .NET Framework #2981, #2940

Added

• Enabled NuGet package auditing via NuGet.org audit source #3024
• Added support for .NET 9 #2946
• Added dependency on System.Security.Cryptography.Pkcs:9.0.0 to address SYSLIB0057#2946
• Added dependency on Microsoft.Bcl.Cryptography:9.0.0 #2946
• Added missing SqlCommand_BeginExecuteReader code sample #3009
• Added support for SqlConnectionOverrides in OpenAsync() API #2433
• Added localization in Czech, Polish, and Turkish #2987

Fixed

• Reverted default value of UseMinimumLoginTimeout context switch to 'true' #2419
• Added missing DynamicallyAccessedMembers attributes in .NET Runtime reference assemblies. #2946
• Synchronized dependencies of Reference Assemblies with Runtime assemblies #2878
• Fixed lazy initialization of the _SqlMetaData hidden column map for .NET Framework #2964

Changed

• Updated Microsoft.Extensions.Caching.Memory to 9.0.0 for all frameworks #2946
• Updated System.Configuration.ConfigurationManager to 9.0.0 #2946
• Updated docs to use absolute links #2949
• Removed System.Text.Json dependency from .NET 8 #2930

Contributors

Thanks to the following public contributors. Their efforts toward this project are very much appreciated.

• @MichelZ
• @EamonHetherton
• @edwardneal
• @deadlydog
• @mus65

For detailed release notes, refer to 6.0.0-preview3.md

Added

• Added a dependency on System.Text.Json 8.0.5 for .NET 8+ and 6.0.10 for other versions #2921
• Added support for JSON native datatype currently in Public preview in SQL Server. #2916, #2892, #2891, #2880, #2882, #2829, #2830
• Added readme to nuget package #2826

Fixed

• Fixed scale serialization when explicitly set to 0 #2411
• Fixed issue blocking GetSchema commands from being enrolled into the current transaction #2876
• Adjusted retry logic to allow errors with negative numbers to be considered transient #2896
• Fixed string formatting in OutOfMemory exceptions #2797
• Increased routing attempts to 10 in netcore for LoginNoFailover and added routing support to LoginWithFailover to standardize routing behavior between netcore and netfx #2873
• Restructured documentation into XML format so that it displays correctly in visual studio #2836, #2822, #2834, #2851, #2863, #2864, #2865, #2869, #2871, #2837, #2821
• Fixed cleanup behavior when column decryption fails. Prevents leaving stale data on the wire for pooled connections #2843, #2825

Changed

• Updated System.Configuration.ConfigurationManager from 8.0.0 to 8.0.1 for .Net 8 #2921
• Updated Microsoft.Extensions.Caching.Memory from 8.0.0 to 8.0.1 for .Net 8 #2921
• Code Health Improvements #2915, #2844, #2812, #2805, #2897, #2376, #2814, #2889, #2885, #2854, #2835, #2442, #2820, #2831, #2907, #2910, #2898, #2928, #2929, #2936, #2939

New Contributors

• @Markeli made their first contribution in #2797
• @EamonHetherton made their first contribution in #2411

For detailed release notes, refer to 6.0.0-preview2.md

[Preview Release 6.0.0-preview1.24240.8] - 2024-08-27

This update brings the below changes over the 5.2 release:

Breaking Changes

• Removed support for .NET Standard. #2386
• Removed UWP (uap) references. #2483

Added

• Added TokenCredential object to take advantage of token caching in ActiveDirectoryAuthenticationProvider. #2380
• Added DateOnly and TimeOnly support to DataTable as a structured parameter. #2258
• Added Microsoft.Data.SqlClient.Diagnostics.SqlClientDiagnostic type in .NET. #2226
• Added scope trace for GenerateSspiClientContext. #2497, #2725

Fixed

• Fixed Socket.Connect timeout issue caused by thread starvation. #2777
• Fixed pending data with SqlDataReader against an encrypted column. #2618
• Fixed Entra authentication when using infinite connection timeout in ActiveDirectoryAuthenticationProvider. #2651
• Fixed GetSchema by excluding unsupported engines due to lack of support for ASSEMBLYPROPERTY function. #2593
• Fixed SSPI retry negotiation with default port in .NET. #2559
• Fixed assembly path in .NET 8.0 and .AssemblyAttributes. #2550
• Fixed certificate chain validation. #2487
• Fixed clone of SqlConnection to include AccessTokenCallback. #2525
• Fixed issue with DateTimeOffset in table-valued parameters, which was introduced in 5.2. #2453
• Fixed ArgumentNullException on SqlDataRecord.GetValue when using user-defined data type on .NET. #2448
• Fixed SqlBuffer and SqlGuild when it's null. #2310
• Fixed SqlBulkCopy.WriteToServer state in a consecutive calls. #2375
• Fixed null reference exception with SqlConnection.FireInfoMessageEventOnUserErrors after introducing the batch command. #2399

Changed

• Updated Microsoft.Data.SqlClient.SNI version to 6.0.0-preview1.24226.4. #2772
• Improved access to SqlAuthenticationProviderManager.Instance and avoid early object initiation. #2636
• Removed undocumented properties of Azure.Identity in ActiveDirectoryAuthenticationProvider. #2562
• Replaced System.Runtime.Caching with Microsoft.Extensions.Caching.Memory. #2493
• Updated EnableOptimizedParameterBinding to only accept text mode commands. #2417
• Updated Azure.Identity version from 1.10.3 to 1.11.4. #2577
• Updated Azure.Core version from 1.35.0 to 1.38.0. #2462
• Updated Azure.Security.KeyVault.Keys version from 4.4.0 to 4.5.0. #2462
• Updated Microsoft.IdentityModel.JsonWebTokens and Microsoft.IdentityModel.Protocols.OpenIdConnect from 6.35.0 to 7.5.0. #2429
• Removed direct dependency to Microsoft.Identity.Client to take the transient dependecy through Azure.Identity. #2577
• Removed unnecessary references Microsoft.Extensions.Caching.Memory and System.Security.Cryptography.Cng after removing .NET Standard. #2577
• Improved memory allocation when reader opened by CommandBehavior.SequentialAccess over the big string columns. #2356
• Improved SSPI by consolidating the context generation to single abstraction and using memory/span for SSPI generation. #2255, #2447
• Reverted the #2281 code changes on ManagedSNI. #2395
• Updated assembly version to 6.0.0.0. #2382
• Code health improvements: #2366, #2369, #2381, #2390, #2392, #2403, #2410, #2413, #2425, #2428, #2440, #2443, #2450, #2466, #2486, #2521, #2522, #2533, #2552, #2560, #2726, #2751, #2811

For detailed release notes, refer to 6.0.0-preview1.md

[Stable release 5.1.6] - 2024-08-27

Fixed

• Fixed Transient fault handling issue with OpenAsync. #1983 #2508
• Fixed AcquireTokenAsync timeout handling for edge cases in ActiveDirectoryAuthenticationProvider. #2706
• Fixed pending data with SqlDataReader against an encrypted column. #2618 #2818

Changed

• Upgraded Azure.Identity version from 1.11.3 to 1.11.4 [#2649] (#2649) [#2529] (#2529) to address CVE-2024-35255.
• Upgraded Microsoft.Identity.Client version from 4.60.0 to 4.61.3 [#2649] (#2649) [#2529] (#2529) to address CVE-2024-35255.
• Added caching to TokenCredential objects to take advantage of token caching. #2776
• Code health improvements: [#2490] (#2490)

[Stable release 5.2.2] - 2024-08-27

Fixed

• Fixed AcquireTokenAsync timeout handling for edge cases in ActiveDirectoryAuthenticationProvider. #2650
• Fixed issue with Socket.Connect in managed SNI. #2779
• Fixed path for AssemblyAttributes in obj folder causing NET 8.0 assembly to appear in NET 6.0 dll. #2789
• Fixed SSPI retry negotiation with default port in .NET. #2815
• Fixed ArgumentNullException on SqlDataRecord.GetValue when using user-defined data type on .NET. #2816
• Fixed pending data with SqlDataReader against an encrypted column. #2817

Changed

• Upgraded Azure.Identity version from 1.11.3 to 1.11.4 #2648 to address CVE-2024-35255.
• Upgraded Microsoft.Identity.Client version from 4.60.0 to 4.61.3 #2648 to address CVE-2024-35255.
• Added caching to TokenCredential objects to take advantage of token caching. #2775