fix(core): order grouped table rows before applying limit

core/src/user-components/tags/table/build-table-sql.ts

@@ -89,6 +89,28 @@ export function buildTableSQLConfig(attrs: TableSQLAttrs): SQLQueryConfig {
 		(c) => c.type === 'measure' && c.processedColumnExpression?.hasAgg && !c.hide
 	);
 
+	// Column-level sorting normally happens after the query so users can re-sort
+	// without another request. A user limit must instead apply to the sorted set;
+	// otherwise the warehouse truncates arbitrary groups and the client only sorts
+	// the surviving rows. Pivoted, comparison, and sparkline render columns still
+	// require client-side sorting because they do not exist in this query.
+	const limitSortColumn =
+		attrs.limit !== undefined && !hasPivots
+			? attrs.unifiedColumns.find(
+					(col) =>
+						col.sort &&
+						col.processedColumnExpression &&
+						col.viz !== 'sparkline' &&
+						col.columnIdForRendering === col.alias &&
+						!col.hide
+				)
+			: undefined;
+	const order =
+		attrs.order ??
+		(limitSortColumn
+			? `${dialect.quoteAlias(limitSortColumn.alias)} ${limitSortColumn.sort}`
+			: undefined);
+
 	const needsSubtotals = Boolean(
 		attrs.subtotals && (hasDimensions || hasPivots) && hasVisibleMeasures && !attrs.limit
 	);
@@ -124,7 +146,7 @@ export function buildTableSQLConfig(attrs: TableSQLAttrs): SQLQueryConfig {
 		date_range: attrs.date_range,
 		having: attrs.having,
 		qualify: attrs.qualify,
-		order: attrs.order,
+		order,
 		limit: attrs.limit,
 		page_size: attrs.page_size,
 		offset: attrs.offset,

core/src/user-components/tags/table/table.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect } from 'vitest';
 import { assertParses, assertRuns, queryClickHouse } from '../../../test-utils/ch-parse';
-import { buildTableSQL, type TableSQLAttrs } from './build-table-sql';
+import { buildTableSQL, buildTableSQLConfig, type TableSQLAttrs } from './build-table-sql';
 import { processColumnExpression } from '../../common/sql-expression-utils';
 import type { UnifiedColumnDefinition } from './unified-column-definition.types';
 import {
@@ -940,6 +940,93 @@ describe('table SQL', () => {
 		expect(new FabricDialect().anyValue('x')).toBe('MAX(x)');
 	});
 
+	it('applies a column sort before limiting grouped rows', () => {
+		const dialect = new ClickHouseDialect();
+		const unifiedColumns = cols(dim('category'), measure('sum(total_sales)'))(dialect);
+		unifiedColumns[1].sort = 'desc';
+
+		const { sql } = buildTableSQL({
+			data: `(
+				SELECT *
+				FROM VALUES(
+					'category String, total_sales UInt32',
+					('small', 1),
+					('largest', 100),
+					('medium', 10)
+				)
+			)`,
+			dataIsSql: true,
+			unifiedColumns,
+			limit: 2,
+			page_size: 10,
+			dialect
+		});
+
+		expect(sql).toMatch(/ORDER BY "sum_total_sales" desc\s+LIMIT 2/);
+		expect(queryClickHouse(sql).trim().split('\n')).toEqual(['largest\t100', 'medium\t10']);
+	});
+
+	it('keeps an explicit table order when a sorted column and limit are both set', () => {
+		const dialect = new ClickHouseDialect();
+		const unifiedColumns = cols(dim('category'), measure('sum(total_sales)'))(dialect);
+		unifiedColumns[1].sort = 'desc';
+
+		const { sql } = buildTableSQL({
+			data: 'demo.daily_orders',
+			unifiedColumns,
+			order: 'category asc',
+			limit: 10,
+			page_size: 10,
+			dialect
+		});
+
+		expect(sql).toMatch(/ORDER BY category asc\s+LIMIT 10/);
+		expect(sql).not.toContain('ORDER BY "sum_total_sales"');
+	});
+
+	it('keeps column sorting client-side when there is no limit', () => {
+		const dialect = new ClickHouseDialect();
+		const unifiedColumns = cols(dim('category'), measure('sum(total_sales)'))(dialect);
+		unifiedColumns[1].sort = 'desc';
+
+		const config = buildTableSQLConfig({
+			data: 'demo.daily_orders',
+			unifiedColumns,
+			dialect
+		});
+
+		expect(config.order).toBeUndefined();
+	});
+
+	it('does not push pivoted, sparkline, or derived column sorts into the source query', () => {
+		const dialect = new ClickHouseDialect();
+		const pivotedColumns = cols(
+			dim('category'),
+			pivot('date', 'year'),
+			measure('sum(total_sales)')
+		)(dialect);
+		pivotedColumns[2].sort = 'desc';
+
+		const sparklineColumns = cols(dim('category'), measure('sum(total_sales)'))(dialect);
+		sparklineColumns[1].sort = 'desc';
+		sparklineColumns[1].viz = 'sparkline';
+
+		const derivedColumns = cols(dim('category'), measure('sum(total_sales)'))(dialect);
+		derivedColumns[1].sort = 'desc';
+		derivedColumns[1].columnIdForRendering = 'sum_total_sales_pct';
+
+		for (const unifiedColumns of [pivotedColumns, sparklineColumns, derivedColumns]) {
+			const config = buildTableSQLConfig({
+				data: 'demo.daily_orders',
+				unifiedColumns,
+				limit: 10,
+				dialect
+			});
+
+			expect(config.order).toBeUndefined();
+		}
+	});
+
 	it('limit disables subtotals even when subtotals=true', () => {
 		const { sql } = buildAllDialects({
 			data: 'demo.daily_orders',