fix: v0.4.2 - remove ReadOnly flag from NOLOCK transaction (go-mssqldb unsupported)

Author: y11t0

CHANGELOG.md

@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.4.2] - 2026-02-18
+
+### Fixed
+- **NOLOCK transaction error on `go-mssqldb`:** `executeQueryReadUncommitted` was opening the
+  transaction with `sql.TxOptions{Isolation: sql.LevelReadUncommitted, ReadOnly: true}`. The
+  `go-mssqldb` driver does not support the `ReadOnly` transaction flag and returned:
+  `"read-only transactions are not supported"`. Removed `ReadOnly: true` — `READ UNCOMMITTED`
+  isolation alone is sufficient: it prevents shared lock acquisition and the transaction is always
+  rolled back via `defer tx.Rollback()` so no data is ever modified.
+
 ## [0.4.1] - 2026-02-18
 
 ### Fixed

pkg/adapter/mssql/mssql.go

@@ -639,7 +639,7 @@ func (m *MSSQLAdapter) ExecuteProcedure(ctx context.Context, name string, params
 // executeQueryReadUncommitted runs the query inside a READ UNCOMMITTED transaction.// This is equivalent to appending WITH (NOLOCK) to every table reference.
 // The transaction is always rolled back afterwards since we only perform reads.
 func (m *MSSQLAdapter) executeQueryReadUncommitted(ctx context.Context, query string, args ...any) (*core.QueryResult, error) {
-	tx, err := m.db.BeginTx(ctx, &sql.TxOptions{Isolation: sql.LevelReadUncommitted, ReadOnly: true})
+	tx, err := m.db.BeginTx(ctx, &sql.TxOptions{Isolation: sql.LevelReadUncommitted})
 	if err != nil {
 		return nil, fmt.Errorf("failed to begin READ UNCOMMITTED transaction: %w", err)
 	}