mssql 0.2.0

A pure Dart driver for Microsoft SQL Server using the TDS 7.4 wire protocol, with TDS 8.0 strict encryption.

Changelog

0.2.0

Fixed

• Encrypted connections (encrypt: true) no longer die with Bad state: Connection closed mid-header after roughly 13-23 statements, and large statements now work over TLS. dart:io's SecureSocket could seal one TDS packet as two TLS records when a write crossed its internal 8 KiB buffer, and SQL Server closes the connection when a packet spans records. Every message on an encrypted connection is now aligned to the packet size (see README, "Encrypted-connection behavior").
• Values that straddle two TDS packets are read correctly. Previously a multi-byte value split across packets could be read as a different number without any error, or fail with TDS stream ended unexpectedly. Reported and fixed independently in the poble-pos and Alexqwesa forks.
• The legacy TLS bridge no longer silently drops all later writes after a single write failure.
• The package compiles under dart2js, so Flutter web builds that reach it no longer fail (it still cannot run on the web; it needs raw sockets). Found in the univelop fork.

Added

• MssqlEncryptMode.strict: TDS 8.0 strict encryption (Encrypt=Strict) for SQL Server 2022+ and Azure SQL. TLS starts before any TDS bytes, the server certificate is always validated, and trustServerCertificate: true is rejected. Select it with encryptMode: on MssqlConnection.connect, connectAzureAd and MssqlPoolConfig. encrypt: bool keeps its old meaning.

Changed

• Encrypted connections request 512-byte TDS packets and pad each message to keep packets aligned, at a cost of up to about 0.5 KB per statement on the wire. Results and plan caching are unaffected. program_name and client_interface_name in sys.dm_exec_sessions show trailing spaces. encrypt: false is unchanged.
• The minimum Dart SDK is now 3.4.0. The previously declared >=3.0.0 could not be installed, because http requires 3.2 or newer.
• Development dependencies updated (lints 6, test 1.32).

Tested against

SQL Server 2017, 2019, 2022 and 2025 on Linux; 2019, 2022 and 2025 on Windows; TDS 8.0 strict on Windows SQL Server 2022 and 2025; Azure SQL Edge; Dart 3.4.0, stable and beta. Not yet verified: Azure SQL Database, Azure AD logins, and strict mode against Azure SQL.

0.1.1

• Remove hardcoded credentials from example and benchmark tool — all connection details now read from environment variables.
• Wrap connection and pool usage in try/finally to guarantee close() on error.

0.1.0

• Initial release.
• Pure-Dart TDS 7.4 driver — no native extensions, no FFI.
• MssqlConnection with SQL Server and Azure AD authentication (bearer token, ROPC, client credentials).
• MssqlPool with configurable min/max, idle reaping, and acquire timeouts.
• Full read support for all common SQL Server types including sql_variant.
• Named-parameter queries using sp_executesql (@name syntax).
• Streaming large result sets with queryStream.
• Multiple result sets via queryMultiple.
• Transaction support — callback form (auto commit/rollback) and manual begin/commit/rollback.
• TLS encryption with optional self-signed certificate trust.
• MssqlException with errorCode, severity, and precedingErrors for multi-error batches.