fix(datagrid): declare write intent when opening a transaction

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Saving on a MySQL or MariaDB server that starts sessions read-only no longer fails with "Cannot execute statement in a READ ONLY transaction". TablePro marks a transaction read-write before it writes instead of inheriting the server default. Same for PostgreSQL, CockroachDB, and Redshift. (#2009)
+- Changing Safe Mode in the connection form now applies to an open connection instead of waiting for a reconnect. (#2009)
+- A read-only error now says whether the database server or Safe Mode refused the write. (#2009)
+
 ## [0.62.0] - 2026-08-02
 
 ### Added

Plugins/MySQLDriverPlugin/MySQLPluginDriver.swift

@@ -95,7 +95,11 @@ final class MySQLPluginDriver: PluginDatabaseDriver, @unchecked Sendable {
     // MARK: - Transaction Management
 
     func beginTransaction() async throws {
-        _ = try await execute(query: "START TRANSACTION")
+        try await beginTransaction(mode: .serverDefault)
+    }
+
+    func beginTransaction(mode: PluginTransactionAccessMode) async throws {
+        _ = try await execute(query: mysqlBeginTransactionStatement(mode: mode))
     }
 
     // MARK: - Query Execution

Plugins/MySQLDriverPlugin/MySQLTransactionStatement.swift

@@ -0,0 +1,6 @@
+import Foundation
+import TableProPluginKit
+
+internal func mysqlBeginTransactionStatement(mode: PluginTransactionAccessMode) -> String {
+    mode == .readWrite ? "START TRANSACTION READ WRITE" : "START TRANSACTION"
+}

Plugins/PostgreSQLDriverPlugin/LibPQDriverCore.swift

@@ -228,6 +228,15 @@ extension LibPQBackedDriver {
     var currentSchema: String? { core.currentSchema }
     var supportsSchemas: Bool { true }
     var supportsTransactions: Bool { true }
+
+    func beginTransaction() async throws {
+        try await beginTransaction(mode: .serverDefault)
+    }
+
+    func beginTransaction(mode: PluginTransactionAccessMode) async throws {
+        _ = try await execute(query: postgresBeginTransactionStatement(mode: mode))
+    }
+
     var serverVersion: String? { core.serverVersion }
     var parameterStyle: ParameterStyle { .dollar }
 

Plugins/PostgreSQLDriverPlugin/PostgreSQLTransactionStatement.swift

@@ -0,0 +1,6 @@
+import Foundation
+import TableProPluginKit
+
+internal func postgresBeginTransactionStatement(mode: PluginTransactionAccessMode) -> String {
+    mode == .readWrite ? "BEGIN READ WRITE" : "BEGIN"
+}

Plugins/TableProPluginKit/PluginDatabaseDriver.swift

@@ -100,6 +100,7 @@ public protocol PluginDatabaseDriver: AnyObject, Sendable {
 
     var supportsTransactions: Bool { get }
     func beginTransaction() async throws
+    func beginTransaction(mode: PluginTransactionAccessMode) async throws
     func commitTransaction() async throws
     func rollbackTransaction() async throws
 
@@ -228,6 +229,10 @@ public extension PluginDatabaseDriver {
         _ = try await execute(query: "BEGIN")
     }
 
+    func beginTransaction(mode: PluginTransactionAccessMode) async throws {
+        try await beginTransaction()
+    }
+
     func commitTransaction() async throws {
         _ = try await execute(query: "COMMIT")
     }

Plugins/TableProPluginKit/PluginTransactionAccessMode.swift

@@ -0,0 +1,6 @@
+import Foundation
+
+public enum PluginTransactionAccessMode: Sendable, Equatable {
+    case serverDefault
+    case readWrite
+}

TablePro.xcodeproj/project.pbxproj

@@ -541,6 +541,7 @@
 				MySQLQueryTimeoutStatement.swift,
 				MySQLSocketTimeout.swift,
 				MySQLStatementClassification.swift,
+				MySQLTransactionStatement.swift,
 			);
 			target = 5ABCC5A62F43856700EAF3FC /* TableProTests */;
 		};

TablePro/Core/Coordinators/QueryExecutionCoordinator+Helpers.swift

@@ -499,7 +499,7 @@ extension QueryExecutionCoordinator {
     ) {
         parent.currentQueryTask = nil
         parent.tabManager.mutate(tabId: tabId) { tab in
-            tab.execution.errorMessage = error.localizedDescription
+            tab.execution.errorMessage = DatabaseWriteRejectionDiagnosis.formatted(error)
             tab.execution.errorQuery = sql
             tab.execution.isExecuting = false
             tab.execution.lastExecutedAt = Date()

TablePro/Core/Coordinators/QueryExecutionCoordinator+Parameters.swift

@@ -242,9 +242,12 @@ extension QueryExecutionCoordinator {
                 }
 
                 let useTransaction = driver.supportsTransactions
+                let transactionKind = OperationKind.worst(of: statements, databaseType: conn.type)
 
                 if useTransaction {
-                    try await driver.beginTransaction()
+                    try await driver.beginTransaction(
+                        mode: transactionKind.declaresWrite ? .readWrite : .serverDefault
+                    )
                 }
 
                 @MainActor func rollbackAndResetState() async {

TablePro/Core/Coordinators/RowEditingCoordinator+Discard.swift

@@ -6,6 +6,7 @@
 import AppKit
 import Foundation
 import os
+import TableProPluginKit
 
 private let discardLogger = Logger(subsystem: "com.TablePro", category: "RowEditingCoordinator+Discard")
 
@@ -14,12 +15,13 @@ extension RowEditingCoordinator {
 
     func executeSidebarChanges(statements: [ParameterizedStatement]) async throws {
         let sqlPreview = statements.map(\.sql).joined(separator: "\n")
+        let kind = OperationKind.from(QueryClassifier.classifyTier(sqlPreview, databaseType: parent.connection.type))
         let decision = await ExecutionGateProvider.shared.authorize(
             OperationRequest(
                 connectionId: parent.connectionId,
                 databaseType: parent.connection.type,
                 sql: sqlPreview,
-                kind: OperationKind.from(QueryClassifier.classifyTier(sqlPreview, databaseType: parent.connection.type)),
+                kind: kind,
                 caller: .userInterface,
                 capabilities: .interactiveUser,
                 operationDescription: String(localized: "Save Sidebar Changes")
@@ -36,7 +38,7 @@ extension RowEditingCoordinator {
         let useTransaction = driver.supportsTransactions
 
         if useTransaction {
-            try await driver.beginTransaction()
+            try await driver.beginTransaction(mode: kind.declaresWrite ? .readWrite : .serverDefault)
         }
 
         do {

TablePro/Core/Coordinators/RowEditingCoordinator+SaveChanges.swift

@@ -6,6 +6,7 @@
 import Foundation
 import os
 import SwiftUI
+import TableProPluginKit
 
 private let saveChangesLogger = Logger(subsystem: "com.TablePro", category: "RowEditingCoordinator")
 
@@ -187,7 +188,7 @@ extension RowEditingCoordinator {
                 let useTransaction = driver.supportsTransactions
 
                 if useTransaction {
-                    try await driver.beginTransaction()
+                    try await driver.beginTransaction(mode: .readWrite)
                 }
 
                 do {
@@ -292,15 +293,21 @@ extension RowEditingCoordinator {
                     errorMessage: error.localizedDescription
                 )
 
+                let diagnosis = DatabaseWriteRejectionDiagnosis.classify(error)
+
                 if let index = parent.tabManager.selectedTabIndex {
                     parent.tabManager.mutate(at: index) {
-                        $0.execution.errorMessage = String(format: String(localized: "Save failed: %@"), error.localizedDescription)
+                        $0.execution.errorMessage = String(
+                            format: String(localized: "Save failed: %@"),
+                            DatabaseWriteRejectionDiagnosis.formatted(error)
+                        )
                     }
                 }
 
                 AlertHelper.showErrorSheet(
                     title: String(localized: "Save Failed"),
-                    message: error.localizedDescription,
+                    message: diagnosis?.errorDescription ?? error.localizedDescription,
+                    recoverySuggestion: diagnosis?.recoverySuggestion,
                     window: parent.contentWindow
                 )
 

TablePro/Core/Database/DatabaseDriver.swift

@@ -190,6 +190,8 @@ protocol DatabaseDriver: AnyObject, Sendable {
     /// Begin a transaction
     func beginTransaction() async throws
 
+    func beginTransaction(mode: PluginTransactionAccessMode) async throws
+
     /// Commit the current transaction
     func commitTransaction() async throws
 
@@ -236,6 +238,10 @@ extension DatabaseDriver {
 
     var queryBuildingPluginDriver: (any PluginDatabaseDriver)? { nil }
 
+    func beginTransaction(mode: PluginTransactionAccessMode) async throws {
+        try await beginTransaction()
+    }
+
     func quoteIdentifier(_ name: String) -> String {
         SQLEscaping.quoteIdentifier(name)
     }

TablePro/Core/Database/DatabaseManager+Principals.swift

@@ -68,7 +68,7 @@ extension DatabaseManager {
     ) async throws {
         let useTransaction = driver.supportsTransactions && rollsBack
         if useTransaction {
-            try await driver.beginTransaction()
+            try await driver.beginTransaction(mode: .readWrite)
         }
 
         var appliedCount = 0

TablePro/Core/Database/DatabaseManager+Schema.swift

@@ -85,7 +85,7 @@ extension DatabaseManager {
             let useTransaction = driver.supportsTransactions
 
             if useTransaction {
-                try await driver.beginTransaction()
+                try await driver.beginTransaction(mode: schemaKind.declaresWrite ? .readWrite : .serverDefault)
             }
 
             do {

TablePro/Core/Database/DatabaseManager+Sessions.swift

@@ -417,6 +417,23 @@ extension DatabaseManager {
         setSession(session, for: sessionId)
     }
 
+    func observeConnectionUpdates() {
+        connectionUpdatedCancellable = AppEvents.shared.connectionUpdated
+            .receive(on: RunLoop.main)
+            .sink { [weak self] connectionId in
+                self?.reconcileSafeModeLevel(for: connectionId)
+            }
+    }
+
+    func reconcileSafeModeLevel(for connectionId: UUID?) {
+        let targetIds = connectionId.map { [$0] } ?? Array(activeSessions.keys)
+        for id in targetIds {
+            guard activeSessions[id] != nil,
+                  let stored = connectionStorage.loadConnection(id: id) else { continue }
+            setSafeModeLevel(stored.safeModeLevel, for: id)
+        }
+    }
+
     func setSafeModeLevel(_ level: SafeModeLevel, for connectionId: UUID) {
         guard var session = activeSessions[connectionId] else { return }
         guard session.safeModeLevel != level || session.connection.safeModeLevel != level else { return }

TablePro/Core/Database/DatabaseManager.swift

@@ -5,6 +5,7 @@
 //  Created by Ngo Quoc Dat on 16/12/25.
 //
 
+import Combine
 import Foundation
 import Observation
 import os
@@ -58,6 +59,8 @@ final class DatabaseManager {
     /// and the wake-from-sleep handler fire for the same connection.
     @ObservationIgnored internal var recoveringConnectionIds = Set<UUID>()
 
+    @ObservationIgnored internal var connectionUpdatedCancellable: AnyCancellable?
+
     @ObservationIgnored internal let ensureConnectedDedup = OnceTask<UUID, Void>()
 
     /// Generation token per connection. A cancelled or superseded attempt keeps running
@@ -119,5 +122,6 @@ final class DatabaseManager {
         self.connectionStorage = connectionStorage
         self.appSettingsStorage = appSettingsStorage
         self.pluginManager = pluginManager
+        observeConnectionUpdates()
     }
 }

TablePro/Core/Database/DatabaseWriteRejectionDiagnosis.swift

@@ -0,0 +1,60 @@
+//
+//  DatabaseWriteRejectionDiagnosis.swift
+//  TablePro
+//
+
+import Foundation
+import TableProPluginKit
+
+internal enum DatabaseWriteRejectionDiagnosis: LocalizedError, Equatable {
+    case serverEnforcedReadOnly(serverMessage: String)
+
+    private static let readOnlyTransactionSqlState = "25006"
+    private static let mysqlReadOnlyServerCodes: Set<Int> = [1_290, 1_836, 1_874]
+
+    static func classify(_ error: Error) -> DatabaseWriteRejectionDiagnosis? {
+        guard let driverError = error as? any PluginDriverError else { return nil }
+
+        if driverError.pluginSqlState == readOnlyTransactionSqlState {
+            return .serverEnforcedReadOnly(serverMessage: driverError.pluginErrorMessage)
+        }
+
+        if let code = driverError.pluginErrorCode, mysqlReadOnlyServerCodes.contains(code) {
+            return .serverEnforcedReadOnly(serverMessage: driverError.pluginErrorMessage)
+        }
+
+        return nil
+    }
+
+    static func formatted(_ error: Error) -> String {
+        guard let diagnosis = classify(error) else { return error.localizedDescription }
+        return [diagnosis.errorDescription, diagnosis.recoverySuggestion]
+            .compactMap { $0 }
+            .joined(separator: "\n\n")
+    }
+
+    var serverMessage: String {
+        switch self {
+        case .serverEnforcedReadOnly(let message): return message
+        }
+    }
+
+    var errorDescription: String? {
+        String(localized: "The database server rejected this write because the connection is read-only.")
+    }
+
+    var recoverySuggestion: String? {
+        String(
+            format: String(
+                localized: """
+                    The database server enforced this, not TablePro's Safe Mode. \
+                    You are most likely connected to a read replica, or the server sets new transactions to read-only. \
+                    Connect to the primary server to write.
+
+                    Server response: %@
+                    """
+            ),
+            serverMessage
+        )
+    }
+}

TablePro/Core/Database/TriggerEditing.swift

@@ -9,6 +9,7 @@
 import Combine
 import Foundation
 import os
+import TableProPluginKit
 
 enum TriggerEditingError: LocalizedError {
     case notConnected
@@ -121,7 +122,7 @@ enum TriggerEditing {
     }
 
     static func runInTransaction(driver: DatabaseDriver, dropSQL: String?, sql: String) async throws {
-        try await driver.beginTransaction()
+        try await driver.beginTransaction(mode: .readWrite)
         do {
             if let dropSQL { _ = try await driver.execute(query: dropSQL) }
             _ = try await driver.execute(query: sql)

TablePro/Core/Plugins/ImportDataSinkAdapter.swift

@@ -129,7 +129,7 @@ final class ImportDataSinkAdapter: PluginImportDataSink, @unchecked Sendable {
     }
 
     func beginTransaction() async throws {
-        try await driver.beginTransaction()
+        try await driver.beginTransaction(mode: .readWrite)
     }
 
     func commitTransaction() async throws {

TablePro/Core/Plugins/PluginDriverAdapter.swift

@@ -516,6 +516,10 @@ final class PluginDriverAdapter: DatabaseDriver, SchemaSwitchable {
         try await pluginDriver.beginTransaction()
     }
 
+    func beginTransaction(mode: PluginTransactionAccessMode) async throws {
+        try await pluginDriver.beginTransaction(mode: mode)
+    }
+
     func commitTransaction() async throws {
         try await pluginDriver.commitTransaction()
     }

TablePro/Core/Services/Execution/DefaultExecutionGate.swift

@@ -45,7 +45,9 @@ internal actor DefaultExecutionGate: ExecutionGate {
         }
 
         if level.blocksAllWrites, effectiveWrite {
-            return .denied(reason: String(localized: "Cannot execute write queries: connection is read-only"))
+            return .denied(reason: String(
+                localized: "Cannot execute write queries: TablePro's Safe Mode is set to read-only for this connection"
+            ))
         }
 
         let isMetadataRead = request.kind == .metadataRead

TablePro/Core/Services/Execution/OperationKind.swift

@@ -4,6 +4,7 @@
 //
 
 import Foundation
+import TableProPluginKit
 
 internal enum OperationKind: Sendable, Equatable {
     case readQuery
@@ -29,6 +30,10 @@ internal extension OperationKind {
         self == .destructiveQuery
     }
 
+    var transactionAccessMode: PluginTransactionAccessMode {
+        declaresWrite ? .readWrite : .serverDefault
+    }
+
     static func from(_ tier: QueryTier) -> OperationKind {
         switch tier {
         case .safe: return .readQuery