@@ -17,8 +17,6 @@ final class QueryViewModel {
1717 // Build search texts asynchronously
1818 searchTextTask?.cancel()
1919 cachedSearchTexts = []
20− searchTextGeneration &+= 1
21− let generation = searchTextGeneration
2220 // Apply the current filter immediately using the inline fallback path
2321 // (the cache was just invalidated). Calling updateFilteredResults()
2422 // rather than `filteredResults = results` avoids briefly showing
@@ -38,12 +36,6 @@ final class QueryViewModel {
3836 }
3937 }.value
4038 guard let self, !Task.isCancelled else { return }
41− // Reject a stale write: if `results` was reassigned while this task
42− // was awaiting, a newer didSet bumped the generation. Task.isCancelled
43− // alone isn't sufficient because two re-queries producing result sets
44− // of identical count would otherwise let this stale, same-length
45− // cachedSearchTexts slip past updateFilteredResults's count guard.
46− guard generation == self.searchTextGeneration else { return }
4739 self.cachedSearchTexts = texts
4840 if !self.filterText.isEmpty {
4941 self.updateFilteredResults()
@@ -53,35 +45,12 @@ final class QueryViewModel {
5345 }
5446 private var cachedSearchTexts: [String] = []
5547 private var searchTextTask: Task<Void, Never>?
56− /// Bumped on every `results` reassignment so the async search-text builder can
57− /// detect it was superseded and drop a stale write (see results.didSet).
58− private var searchTextGeneration = 0
5948 var columns: [String] = []
6049 var columnOrder: [String] = []
6150 var hiddenColumns: Set<String> = []
62− /// The full persisted set of hidden columns for the current stream, including
63− /// ones absent from the current result. Hiding a column drops it from the
64− /// SELECT list, so it's missing from the very next result and `hiddenColumns`
65− /// (only the columns present) forgets it — the next save would then erase the
66− /// preference. This keeps the intent, mirroring LiveTailViewModel.
67− private(set) var savedHiddenColumns: Set<String> = []
68− /// The persisted column order including columns absent from the current
69− /// result (the order counterpart of `savedHiddenColumns`), so saving doesn't
70− /// drop a hidden column's position and it returns to its place when shown.
71− private var savedColumnOrder: [String] = []
7251 var autoHiddenColumns: Set<String> = []
7352 /// Column config from a saved query, applied on next query execution.
7453 var pendingColumnConfig: ColumnConfiguration?
75−
76− /// The connection and stream the editor text and results belong to. The view
77− /// model outlives QueryView (switching tabs keeps the query), so the view
78− /// compares this on appear to catch a stream/server change made while another
79− /// tab was showing.
80− struct BoundContext: Equatable {
81− let connectionID: UUID?
82− let stream: String
83− }
84− var boundContext: BoundContext?
8554 private var currentStream: String?
8655 var isLoading = false
8756 var errorMessage: String?
@@ -99,23 +68,10 @@ final class QueryViewModel {
9968 var schemaFields: [SchemaField] = []
10069 /// The stream of the most recent `loadSchema` call, used to drop a stale
10170 /// in-flight response when the user rapidly switches streams.
102− private(set) var latestSchemaStream: String?
103− /// The stream of the most recent `executeQuery` call. Defense-in-depth
104− /// alongside `queryGeneration`/task cancellation: drops a stale in-flight
105− /// query response if a newer query for a different stream supersedes it
106− /// without going through the normal cancel path.
107− private var latestQueryStream: String?
71+ private var latestSchemaStream: String?
10872
10973 // Query task for cancellation
11074 private var queryTask: Task<Void, Never>?
111− /// Bumped at the start of every `executeQuery`. The task captures this value
112− /// and only clears `isLoading` on exit if it's still the active query — so a
113− /// superseded query's late cleanup doesn't drop the loading indicator that
114− /// the newer query set. Without this, `isLoading = false` had to live in
115− /// every caller of `cancel()` (cancelQuery, clearResults, superseding
116− /// executeQuery) and a future cancel path that forgot to set it would wedge
117− /// the spinner indefinitely.
118− private var queryGeneration = 0
11975
12076 // Time range
12177 var timeRangeOption: TimeRangeOption = .last1Hour
@@ -212,16 +168,9 @@ final class QueryViewModel {
212168 return columnOrder.filter { !allHidden.contains($0) }
213169 }
214170
215− /// Whether any column is hidden — including saved-hidden columns that aren't
216− /// in the current result, which "Show All" can bring back.
217− var hasHiddenColumns: Bool {
218− !hiddenColumns.isEmpty || !autoHiddenColumns.isEmpty || !savedHiddenColumns.isEmpty
219− }
220−
221171 func toggleColumnVisibility(_ column: String) {
222172 if hiddenColumns.contains(column) {
223173 hiddenColumns.remove(column)
224− savedHiddenColumns.remove(column)
225174 } else if autoHiddenColumns.contains(column) {
226175 autoHiddenColumns.remove(column)
227176 } else {
@@ -230,7 +179,6 @@ final class QueryViewModel {
230179 let visibleCount = columnOrder.count - allHidden.count
231180 if visibleCount > 1 {
232181 hiddenColumns.insert(column)
233− savedHiddenColumns.insert(column)
234182 }
235183 }
236184 saveColumnConfig()
@@ -239,7 +187,6 @@ final class QueryViewModel {
239187
240188 func showAllColumns() {
241189 hiddenColumns.removeAll()
242− savedHiddenColumns.removeAll()
243190 autoHiddenColumns.removeAll()
244191 saveColumnConfig()
245192 updateSQLColumns()
@@ -269,116 +216,32 @@ final class QueryViewModel {
269216
270217 func resetColumnConfig() {
271218 columnOrder = columns
272− savedColumnOrder = []
273219 hiddenColumns.removeAll()
274− savedHiddenColumns.removeAll()
275220 autoHiddenColumns.removeAll()
276221 saveColumnConfig()
277222 updateSQLColumns()
278223 }
279224
280− /// Rewrites the SELECT clause of `sqlQuery` to reflect the user's column
281− /// choices (order and hidden columns; auto-hidden columns stay display-only).
225+ /// Rewrites the SELECT clause of `sqlQuery` to reflect the current `visibleColumns`.
282226 func updateSQLColumns() {
283− guard let range = SQLTokenizer.selectColumnListRange(in: sqlQuery),
284− let currentList = Self.parseColumnList(sqlQuery[range]) else { return }
285−
286− // Project the user's choices only. `autoHiddenColumns` is a display
287− // heuristic for the current rows (the field is empty in all of them);
288− // baking it into the SQL would stop the field from ever being fetched
289− // again, even for a time range where it has values.
290− let visible = columnOrder.filter { !hiddenColumns.contains($0) }
291− guard !visible.isEmpty else { return }
227+ guard let range = SQLTokenizer.selectColumnListRange(in: sqlQuery) else { return }
292228
293− // Columns an explicit list names that aren't in the results: Parseable
294− // omits all-null fields from query JSON, so a sparse listed field can be
295− // missing from `columns`. Keep it (unless the user hid it) rather than
296− // silently dropping it from the SELECT on the next rewrite.
297− var listedButAbsent: [String] = []
298− var excludesHiddenColumn = false
299− if case .identifiers(let names) = currentList {
300− let present = Set(columns)
301− listedButAbsent = names.filter { !present.contains($0) && !savedHiddenColumns.contains($0) }
302− // A column the user hid is absent from these results precisely
303− // because this list was narrowed to exclude it.
304− excludesHiddenColumn = !savedHiddenColumns.isSubset(of: present)
305− }
229+ let visible = visibleColumns
230+ guard !visible.isEmpty else { return }
306231
307232 let newColumnList: String
308233 // Use `*` whenever every column is visible, regardless of display order —
309234 // reordering columns (a set-preserving permutation) must not pin the query
310− // to an explicit snapshot that hides newly-appearing fields on re-query —
311− // unless the list is explicit because it leaves out a hidden column, which
312− // `*` would fetch again.
313− if !excludesHiddenColumn && visible.count == columns.count && Set(visible) == Set(columns) {
235+ // to an explicit snapshot that hides newly-appearing fields on re-query.
236+ if visible.count == columns.count && Set(visible) == Set(columns) {
314237 newColumnList = "*"
315238 } else {
316− newColumnList = (visible + listedButAbsent).map { Self.escapeSQLIdentifier($0) }.joined(separator: ", ")
239+ newColumnList = visible.map { Self.escapeSQLIdentifier($0) }.joined(separator: ", ")
317240 }
318241
319242 sqlQuery.replaceSubrange(range, with: newColumnList)
320243 }
321244
322− enum ColumnListShape: Equatable {
323− case star
324− /// Plain column references, as the column names they resolve to.
325− case identifiers([String])
326− }
327−
328− /// Parses a SELECT list the column manager can regenerate without changing
329− /// what the query computes: `*`, or a comma-separated list of plain column
330− /// references. Anything else — aggregates, expressions, aliases
331− /// (`count(*) AS n`), qualified names — returns nil: rewriting it with `*` or
332− /// bare result keys would break the query, so the column manager then only
333− /// hides/reorders client-side.
334− nonisolated static func parseColumnList(_ list: Substring) -> ColumnListShape? {
335− let tokens = SQLTokenizer.tokenize(String(list)).filter { !$0.kind.isTrivia }
336− if tokens.count == 1, tokens[0].kind == .star { return .star }
337− guard tokens.count % 2 == 1 else { return nil }
338− var names: [String] = []
339− for (index, token) in tokens.enumerated() {
340− if index % 2 == 1 {
341− guard token.kind == .comma else { return nil }
342− continue
343− }
344− switch token.kind {
345− // DataFusion folds unquoted identifiers to lowercase.
346− case .identifier(let name): names.append(name.lowercased())
347− case .quotedIdentifier(let name): names.append(name)
348− default: return nil
349− }
350− }
351− return .identifiers(names)
352− }
353−
354− /// Inserts `newColumns` into `order`, placing each one that appears in
355− /// `reference` (a saved order) right after its nearest saved predecessor
356− /// that's already placed — or first if none is — and appending the rest.
357− /// Used to keep the positions of columns that are absent for a while.
358− nonisolated static func mergedColumnOrder(
359− _ order: [String], inserting newColumns: [String], reference: [String]
360− ) -> [String] {
361− var result = order
362− let referenceIndex = Dictionary(reference.enumerated().map { ($1, $0) }, uniquingKeysWith: { first, _ in first })
363− let pending = newColumns.filter { referenceIndex[$0] == nil }
364− let positioned = newColumns
365− .filter { referenceIndex[$0] != nil }
366− .sorted { referenceIndex[$0]! < referenceIndex[$1]! }
367− for column in positioned where !result.contains(column) {
368− let savedIndex = referenceIndex[column]!
369− let predecessor = reference[..<savedIndex].reversed().first { result.contains($0) }
370− if let predecessor, let position = result.firstIndex(of: predecessor) {
371− result.insert(column, at: position + 1)
372− } else {
373− result.insert(column, at: 0)
374− }
375− }
376− for column in pending where !result.contains(column) {
377− result.append(column)
378− }
379− return result
380− }
381−
382245 // MARK: - Column Configuration Persistence
383246
384247 struct ColumnConfiguration: Codable {
@@ -392,16 +255,7 @@ final class QueryViewModel {
392255
393256 private func saveColumnConfig() {
394257 guard let stream = currentStream else { return }
395− // Persist the full intended hidden set and order, not just the currently
396− // present columns (see `savedHiddenColumns` / `savedColumnOrder`).
397− let present = Set(columnOrder)
398− let order = Self.mergedColumnOrder(
399− columnOrder,
400− inserting: savedColumnOrder.filter { !present.contains($0) },
401− reference: savedColumnOrder
402− )
403− savedColumnOrder = order
404− let config = ColumnConfiguration(order: order, hidden: savedHiddenColumns.union(hiddenColumns))
258+ let config = ColumnConfiguration(order: columnOrder, hidden: hiddenColumns)
405259 if let data = try? JSONEncoder().encode(config) {
406260 UserDefaults.standard.set(data, forKey: Self.columnConfigKey(for: stream))
407261 }
@@ -430,9 +284,7 @@ final class QueryViewModel {
430284
431285 guard let config else {
432286 columnOrder = extractedColumns
433− savedColumnOrder = []
434287 hiddenColumns = []
435− savedHiddenColumns = []
436288 return
437289 }
438290
@@ -445,8 +297,6 @@ final class QueryViewModel {
445297 merged.append(col)
446298 }
447299 columnOrder = merged
448− savedColumnOrder = config.order
449− savedHiddenColumns = config.hidden
450300 hiddenColumns = config.hidden.intersection(extractedSet)
451301
452302 // The `visibleCount > 1` guard in toggleColumnVisibility only covers
@@ -540,13 +390,6 @@ final class QueryViewModel {
540390
541391 // Cancel any in-flight query
542392 queryTask?.cancel()
543− // Bump the generation so the in-flight task's cleanup can detect that
544− // it has been superseded and skip its `isLoading = false` (which would
545− // otherwise race with the `isLoading = true` below and briefly drop
546− // the loading indicator during this query).
547− queryGeneration &+= 1
548− let generation = queryGeneration
549− latestQueryStream = stream
550393
551394 isLoading = true
552395 errorMessage = nil
@@ -555,16 +398,6 @@ final class QueryViewModel {
555398 let startTime = CFAbsoluteTimeGetCurrent()
556399
557400 let task = Task {
558− // Always clear the spinner on exit when this is still the active
559− // query. The defer runs on every path (success, error, and the
560− // cancellation cases that previously returned before reaching the
561− // trailing `isLoading = false`), so the spinner can never wedge
562− // even if a new cancel path is added without resetting it.
563− defer {
564− if generation == queryGeneration {
565− isLoading = false
566− }
567− }
568401 do {
569402 try Task.checkCancellation()
570403 let queryResults = try await client.query(sql: sql, startTime: startDate, endTime: endDate)
@@ -574,9 +407,6 @@ final class QueryViewModel {
574407 // cancellation landing just after the check above would otherwise
575408 // let a stale query clobber the newer one's results/columns.
576409 guard !Task.isCancelled else { return }
577− // Drop the response if a newer query (possibly for a different
578− // stream) has since been launched without cancelling this task.
579− guard latestQueryStream == stream else { return }
580410
581411 results = queryResults
582412 // Drop any prior row selection: the new result set reassigns row
@@ -586,13 +416,9 @@ final class QueryViewModel {
586416 queryDuration = CFAbsoluteTimeGetCurrent() - startTime
587417 resultCount = results.count
588418
589− // Detect if results were likely truncated. We know the cap for
590− // auto-generated queries; for user-entered SQL (which includes the
591− // default query `setDefaultQuery` writes into the editor — the common
592− // stream-selection path), parse a trailing `LIMIT n` so the indicator
593− // still fires when the row count lands exactly on the limit.
594− let effectiveLimit = usedAutoLimit ? limit : Self.trailingLimit(in: sql)
595− resultsTruncated = effectiveLimit.map { results.count == $0 } ?? false
419+ // Detect if results were likely truncated (only meaningful
420+ // for auto-generated queries where we control the LIMIT)
421+ resultsTruncated = usedAutoLimit && results.count == limit
596422
597423 // Extract columns in a single pass, with priority fields first,
598424 // then apply any saved column configuration for this stream
@@ -619,23 +445,12 @@ final class QueryViewModel {
619445 return
620446 } catch {
621447 guard !Task.isCancelled else { return }
622− // Same supersession guard as the success path: a stale failed
623− // query must not clobber a newer query's state.
624− guard latestQueryStream == stream else { return }
625448 errorMessage = ParseableError.userFriendlyMessage(for: error)
626449 if let serverError = error as? ParseableError,
627450 case .serverError(_, let msg) = serverError,
628− let pos = SQLErrorPosition.parse(from: msg),
629− sqlQuery == sql {
630− // The server's line/column is relative to the *submitted* SQL.
631− // Only map it back into the editor when the editor still holds
632− // that same text — if the user edited the query while it was in
633− // flight, the position no longer corresponds to what's displayed
634− // and would underline an unrelated span. (`sqlQuery`'s didSet
635− // already cleared errorRange on that edit, so leaving it nil here
636− // keeps the editor unmarked.)
451+ let pos = SQLErrorPosition.parse(from: msg) {
637452 errorRange = SQLTokenizer.errorHighlightRange(
638− line: pos.line, column: pos.column, in: sql
453+ line: pos.line, column: pos.column, in: sqlQuery
639454 )
640455 }
641456 results = []
@@ -645,10 +460,10 @@ final class QueryViewModel {
645460 // report stale column names after the failure.
646461 columnOrder = []
647462 hiddenColumns = []
648− savedHiddenColumns = []
649− savedColumnOrder = []
650463 autoHiddenColumns = []
651464 }
465+
466+ isLoading = false
652467 }
653468 queryTask = task
654469 await task.value
@@ -813,8 +628,6 @@ final class QueryViewModel {
813628 columns = []
814629 columnOrder = []
815630 hiddenColumns = []
816− savedHiddenColumns = []
817− savedColumnOrder = []
818631 autoHiddenColumns = []
819632 currentStream = nil
820633 resultCount = 0
@@ -824,11 +637,6 @@ final class QueryViewModel {
824637 errorRange = nil
825638 resultsTruncated = false
826639 schemaFields = []
827− // Keep the stream trackers consistent with the cleared schema/results so
828− // a later reload guard never sees a non-nil stream paired with empty data.
829− latestSchemaStream = nil
830− latestQueryStream = nil
831− boundContext = nil
832640 }
833641
834642 /// Modifies `sqlQuery` to add a column-value filter condition.
@@ -838,139 +646,75 @@ final class QueryViewModel {
838646 let condition: String
839647 if let value, value != .null {
840648 let literal = value.sqlLiteral
841− // Exclude with `IS DISTINCT FROM`, not `<>`: under SQL's three-valued
842− // logic `NULL <> 'x'` is NULL, so `<>` also dropped every row where the
843− // column is missing/NULL — common for sparse fields — which "exclude
844− // this value" doesn't ask for (the live-tail exclude keeps them too).
845− condition = exclude
846− ? "\(escapedCol) IS DISTINCT FROM \(literal)"
847− : "\(escapedCol) = \(literal)"
649+ condition = exclude ? "\(escapedCol) <> \(literal)" : "\(escapedCol) = \(literal)"
848650 } else {
849651 condition = exclude ? "\(escapedCol) IS NOT NULL" : "\(escapedCol) IS NULL"
850652 }
851653
852− let sql = sqlQuery.trimmingCharacters(in: .whitespacesAndNewlines)
654+ var sql = sqlQuery.trimmingCharacters(in: .whitespacesAndNewlines)
853655 if sql.isEmpty { return }
854656
855657 // Locate the top-level WHERE and the first trailing clause using the
856658 // tokenizer rather than a raw regex, so keywords inside quoted
857659 // identifiers, string literals, comments, or subqueries are ignored.
858− let tokens = SQLTokenizer.tokenize(sql)
660+ let tailKeywords: Set<String> = ["ORDER", "GROUP", "HAVING", "LIMIT", "OFFSET"]
859661 var depth = 0
860− // WHERE and the trailing clauses only follow the top-level FROM. Keywords
861− // before it belong to the SELECT list — e.g. a field named `offset` or
862− // `limit` (which the tokenizer reports as keywords) — and must not be
863− // mistaken for clause starts.
864− var fromSeen = false
865− var whereIndex: Int?
866− var tailIndex: Int?
662+ var whereEnd: String.Index?
663+ var tailStart: String.Index?
867664 // Track whether the existing WHERE body has a top-level OR — only then does
868665 // AND-ing a new condition need parentheses to preserve precedence.
869666 var bodyHasTopLevelOr = false
870− // The last token that is actual SQL — not whitespace, a comment, or a
871− // statement-terminating `;`. New text is spliced in right after such
872− // tokens (never at the raw end of the string), so a trailing `;` or a
873− // trailing `-- comment` stays at the end instead of swallowing the
874− // appended condition: `... LIMIT 10;` must not become `... LIMIT 10; WHERE`,
875− // and `... -- note` must not become `... -- note WHERE <commented out>`.
876− func isSignificant(_ token: SQLTokenizer.Token) -> Bool {
877− !token.kind.isTrivia && token.kind != .other(";")
878− }
879− func nextSignificantKind(after index: Int) -> SQLTokenizer.TokenKind? {
880− tokens[(index + 1)...].first(where: { isSignificant($0) })?.kind
881− }
882− // Whether the keyword at `index` actually opens a trailing clause. ORDER and
883− // GROUP must be followed by BY (so `WITHIN GROUP (…)` or a column named
884− // `order` doesn't count), and LIMIT/OFFSET by their row count (so a column
885− // named `offset` in `WHERE offset > 5` doesn't cut the WHERE body short).
886− func startsTrailingClause(_ keyword: String, at index: Int) -> Bool {
887− switch keyword {
888− case "ORDER", "GROUP":
889− return nextSignificantKind(after: index) == .keyword("BY")
890− case "LIMIT", "OFFSET":
891− if case .number = nextSignificantKind(after: index) { return true }
892− return false
893− case "HAVING":
894− return true
895− default:
896− return false
897− }
898− }
899− var lastSignificant: Int?
900− for (idx, token) in tokens.enumerated() {
901− if isSignificant(token) { lastSignificant = idx }
667+ for token in SQLTokenizer.tokenize(sql) {
902668 switch token.kind {
903669 case .leftParen:
904670 depth += 1
905671 case .rightParen:
906672 depth = max(0, depth - 1)
907− case .keyword("FROM") where depth == 0:
908− fromSeen = true
909− case .keyword(let kw) where depth == 0 && fromSeen:
910− if kw == "WHERE", whereIndex == nil {
911− whereIndex = idx
912− // A trailing clause seen *before* the WHERE (e.g. the GROUP BY of
913− // the first SELECT in `... GROUP BY a UNION ALL SELECT ... WHERE`)
914− // doesn't end this WHERE's body. Keeping it would make the body
915− // range run backwards (a trapping `Range`), so look for the
916− // body's end afresh after the WHERE.
917− tailIndex = nil
918− } else if tailIndex == nil, startsTrailingClause(kw, at: idx) {
919− tailIndex = idx
920− } else if kw == "OR", whereIndex != nil, tailIndex == nil {
673+ case .keyword(let kw) where depth == 0:
674+ if kw == "WHERE", whereEnd == nil {
675+ whereEnd = token.range.upperBound
676+ } else if tailKeywords.contains(kw), tailStart == nil {
677+ tailStart = token.range.lowerBound
678+ } else if kw == "OR", whereEnd != nil, tailStart == nil {
921679 bodyHasTopLevelOr = true
922680 }
923681 default:
924682 break
925683 }
926684 }
927− // Nothing but comments/semicolons — there's no statement to filter.
928− guard let lastSignificant else { return }
929−
930− // Each branch rebuilds the query from slices of the original text, keeping
931− // the user's line breaks: joining pieces with single spaces would pull the
932− // text after a `-- comment` onto the comment's line and comment it out.
933− // Text spliced directly in front of another token (`(a = 1)ORDER BY`) needs
934− // a space so the two don't fuse (`... IS NULLORDER BY`).
935− func separated(_ rest: Substring) -> String {
936− guard let next = rest.first, !next.isWhitespace, next != ";" else { return String(rest) }
937− return " " + rest
938− }
939− if let whereIndex {
940− // The WHERE body runs up to the first trailing clause, or to the end
941− // of the statement. Only its significant tokens bound the splice, so a
942− // comment between the body and ORDER BY stays after the new condition.
943− let bodyEndIndex = tailIndex ?? (lastSignificant + 1)
944− let bodyIndices = (whereIndex + 1)..<bodyEndIndex
945− if let first = bodyIndices.first(where: { isSignificant(tokens[$0]) }),
946− let last = bodyIndices.last(where: { isSignificant(tokens[$0]) }) {
947− // Parenthesize the existing WHERE body before AND-ing the new
948− // condition only when it has a top-level OR, otherwise the OR
949− // silently changes meaning: `WHERE a = 1 OR b = 2` would become
950− // `WHERE a = 1 OR b = 2 AND c = 3`, which SQL binds as
951− // `a = 1 OR (b = 2 AND c = 3)` rather than the intended
952− // `(a = 1 OR b = 2) AND c = 3`. A body without a top-level OR is
953− // left un-parenthesized so simple filters stay readable.
954− let bodyStart = tokens[first].range.lowerBound
955− let bodyEnd = tokens[last].range.upperBound
956− let body = sql[bodyStart..<bodyEnd]
957− let wrappedBody = bodyHasTopLevelOr ? "(\(body))" : String(body)
958− sqlQuery = "\(sql[..<bodyStart])\(wrappedBody) AND \(condition)\(separated(sql[bodyEnd...]))"
685+
686+ if let whereEnd {
687+ // Parenthesize the existing WHERE body before AND-ing the new
688+ // condition only when it has a top-level OR, otherwise the OR
689+ // silently changes meaning: `WHERE a = 1 OR b = 2` would become
690+ // `WHERE a = 1 OR b = 2 AND c = 3`, which SQL binds as
691+ // `a = 1 OR (b = 2 AND c = 3)` rather than the intended
692+ // `(a = 1 OR b = 2) AND c = 3`. A body without a top-level OR is
693+ // left un-parenthesized so simple filters stay readable.
694+ let bodyEnd = tailStart ?? sql.endIndex
695+ let head = sql[..<whereEnd]
696+ let body = sql[whereEnd..<bodyEnd].trimmingCharacters(in: .whitespacesAndNewlines)
697+ let tail = sql[bodyEnd...].trimmingCharacters(in: .whitespacesAndNewlines)
698+ // An empty WHERE body (e.g. a half-written `... WHERE` with no
699+ // condition yet, or `WHERE` immediately followed by ORDER/GROUP/
700+ // LIMIT) would otherwise produce `WHERE AND <condition>` — a
701+ // dangling AND with no left operand. Drop the AND in that case.
702+ if body.isEmpty {
703+ sql = "\(head) \(condition)"
959704 } else {
960− // An empty WHERE body (e.g. a half-written `... WHERE` with no
961− // condition yet, or `WHERE` immediately followed by ORDER/GROUP/
962− // LIMIT) would otherwise produce `WHERE AND <condition>` — a
963− // dangling AND with no left operand. Drop the AND in that case.
964− let whereEnd = tokens[whereIndex].range.upperBound
965− sqlQuery = "\(sql[..<whereEnd]) \(condition)\(separated(sql[whereEnd...]))"
705+ let wrappedBody = bodyHasTopLevelOr ? "(\(body))" : body
706+ sql = "\(head) \(wrappedBody) AND \(condition)"
707+ }
708+ if !tail.isEmpty {
709+ sql += " \(tail)"
966710 }
967− } else if let tailIndex {
968− let tailStart = tokens[tailIndex].range.lowerBound
969− sqlQuery = "\(sql[..<tailStart])WHERE \(condition) \(sql[tailStart...])"
711+ } else if let tailStart {
712+ sql.insert(contentsOf: "WHERE \(condition) ", at: tailStart)
970713 } else {
971− let statementEnd = tokens[lastSignificant].range.upperBound
972− sqlQuery = "\(sql[..<statementEnd]) WHERE \(condition)\(separated(sql[statementEnd...]))"
714+ sql += " WHERE \(condition)"
973715 }
716+
717+ sqlQuery = sql
974718 }
975719
976720 /// Sets the default query for the given stream, returning `true` if the
@@ -998,26 +742,9 @@ final class QueryViewModel {
998742 "\"\(identifier.replacingOccurrences(of: "\"", with: "\"\""))\""
999743 }
1000744
1001− /// Extracts the row cap from a trailing `LIMIT n` clause (tolerating a trailing
1002− /// semicolon/whitespace), used to detect when a result set was truncated.
1003− /// Returns nil when there's no recognizable trailing `LIMIT` — e.g. when the
1004− /// query uses `LIMIT n OFFSET m` — so we never report a false truncation.
1005− nonisolated static func trailingLimit(in sql: String) -> Int? {
1006− let pattern = #"(?i)\bLIMIT\s+(\d+)\s*;?\s*$"#
1007− guard let regex = try? NSRegularExpression(pattern: pattern) else { return nil }
1008− let range = NSRange(sql.startIndex..<sql.endIndex, in: sql)
1009− guard let match = regex.firstMatch(in: sql, range: range),
1010− let numberRange = Range(match.range(at: 1), in: sql) else { return nil }
1011− return Int(sql[numberRange])
1012− }
1013−
1014745 // MARK: - Query History
1015746
1016747 private func addToHistory(_ entry: QueryHistoryEntry) {
1017− // Start from what's persisted, not this instance's copy: a model created
1018− // earlier (e.g. one whose query finished after a reconnect replaced it)
1019− // would otherwise overwrite newer entries saved by the current one.
1020− queryHistory = Self.loadHistory()
1021748 // Deduplicate consecutive identical queries
1022749 if queryHistory.first?.sql == entry.sql { return }
1023750 queryHistory.insert(entry, at: 0)