feat: fallback to ctid for editing tables without primary key

When a table has no PRIMARY KEY, use PostgreSQL's ctid (physical row ID)
to identify rows for UPDATE/DELETE operations instead of blocking edits.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/table-viewer/TableDataView.tsx

@@ -94,30 +94,46 @@ export function TableDataView({ connectionId, schema, table }: Props) {
     [pendingChanges, isReadOnly]
   );
 
+  const usesCtid = pkColumns.length === 0;
+
   const handleCommit = async () => {
-    if (!data || pkColumns.length === 0) {
-      toast.error("Cannot save: no primary key detected");
+    if (!data) return;
+    if (pkColumns.length === 0 && (!data.ctids || data.ctids.length === 0)) {
+      toast.error("Cannot save: no primary key and no ctid available");
       return;
     }
     setIsSaving(true);
     try {
       for (const [_key, change] of pendingChanges) {
         const row = data.rows[change.rowIndex];
-        const pkValues = pkColumns.map((pkCol) => {
-          const idx = data.columns.indexOf(pkCol);
-          return row[idx];
-        });
         const colName = data.columns[change.colIndex];
 
-        await updateRowApi({
-          connectionId,
-          schema,
-          table,
-          pkColumns,
-          pkValues: pkValues as unknown[],
-          column: colName,
-          value: change.value,
-        });
+        if (usesCtid) {
+          await updateRowApi({
+            connectionId,
+            schema,
+            table,
+            pkColumns: [],
+            pkValues: [],
+            column: colName,
+            value: change.value,
+            ctid: data.ctids[change.rowIndex],
+          });
+        } else {
+          const pkValues = pkColumns.map((pkCol) => {
+            const idx = data.columns.indexOf(pkCol);
+            return row[idx];
+          });
+          await updateRowApi({
+            connectionId,
+            schema,
+            table,
+            pkColumns,
+            pkValues: pkValues as unknown[],
+            column: colName,
+            value: change.value,
+          });
+        }
       }
       setPendingChanges(new Map());
       queryClient.invalidateQueries({
@@ -182,6 +198,14 @@ export function TableDataView({ connectionId, schema, table }: Props) {
             Read-Only
           </span>
         )}
+        {!isReadOnly && usesCtid && (
+          <span
+            className="rounded bg-orange-500/10 px-1.5 py-0.5 text-[10px] font-medium text-orange-600 dark:text-orange-400"
+            title="This table has no primary key. Edits use physical row ID (ctid), which may change after VACUUM or concurrent writes."
+          >
+            No PK — using ctid
+          </span>
+        )}
         <Filter className="h-3.5 w-3.5 text-muted-foreground" />
         <Input
           placeholder="WHERE clause (e.g. id > 10)"