Add SQL-99 compliant parenthesized SELECT support in UNION operations

src/38query.js

@@ -177,6 +177,53 @@ function queryfn3(query) {
 	// Remove distinct values
 	doDistinct(query);
 
+	// If we have UNION/UNION ALL/EXCEPT/INTERSECT with ORDER BY/LIMIT before it,
+	// apply ORDER BY and LIMIT to the first SELECT before combining.
+	// This handles the pattern: SELECT ... ORDER BY ... LIMIT ... UNION ALL SELECT ... ORDER BY ... LIMIT ...
+	// We only do this if the UNION branch also has ORDER BY/LIMIT (pattern 2), not if ORDER BY is at the end (pattern 1).
+	var unionBranchHasOrder = ['unionallfn', 'unionfn', 'exceptfn', 'intersectfn'].some(
+		function (fnName) {
+			var fn = query[fnName];
+			return fn && fn.query && (fn.query.orderfn || fn.query.limit);
+		}
+	);
+
+	if (unionBranchHasOrder && (query.orderfn || query.limit)) {
+		// Apply ordering to first SELECT's data
+		if (query.orderfn) {
+			// Populate order keys before sorting (needed for UNION queries)
+			if (query.orderColumns) {
+				for (var i = 0, ilen = query.data.length; i < ilen; i++) {
+					for (var idx = 0; idx < query.orderColumns.length; idx++) {
+						var v = query.orderColumns[idx];
+						var key = '$$$' + idx;
+						var r = query.data[i];
+						if (v instanceof yy.Column && r[v.columnid] !== undefined) {
+							r[key] = r[v.columnid];
+						} else if (v instanceof yy.Column) {
+							r[key] = undefined;
+						} else {
+							r[key] = undefined;
+						}
+						if (i === 0 && query.removeKeys.indexOf(key) === -1) {
+							query.removeKeys.push(key);
+						}
+					}
+				}
+			}
+			query.data = query.data.sort(query.orderfn);
+			// Clear orderfn so it doesn't get applied again after UNION
+			query.orderfn = null;
+		}
+		// Apply limit to first SELECT's data
+		if (query.limit) {
+			doLimit(query);
+			// Clear limit so it doesn't get applied again after UNION
+			query.limit = null;
+			query.offset = null;
+		}
+	}
+
 	// UNION / UNION ALL
 	if (query.unionallfn) {
 		// TODO Simplify this part of program

src/alasqlparser.jison

@@ -439,6 +439,7 @@ Statement
 	| Reindex
 	| RenameTable
 	| Select
+	| ParenthesizedSelect
 	| ShowCreateTable
 	| ShowColumns
 	| ShowDatabases
@@ -541,6 +542,15 @@ Select
 		    if(yy.exists) $$.exists = yy.exists.slice();
 /*		    if(yy.queries) $$.queries = yy.queries;
 			delete yy.queries;
+*/		}
+	| LPAR Select RPAR UnionClause OrderClause LimitClause
+		{
+			$$ = $2;
+			yy.extend($$,$4);
+			yy.extend($$,$5); yy.extend($$,$6);
+		    if(yy.exists) $$.exists = yy.exists.slice();
+/*		    if(yy.queries) $$.queries = yy.queries;
+			delete yy.queries;
 */		}
 	| ParenthesizedSelect UnionClause OrderClause LimitClause
 		{
@@ -556,6 +566,11 @@ Select
 		}
 	;
 
+ParenthesizedSelect
+	: LPAR Select RPAR
+		{ $$ = $2; }
+	;
+
 SelectWithoutOrderOrLimit
 	: SelectClause RemoveClause? IntoClause FromClause PivotClause? WhereClause GroupClause UnionClause
 		{

test/test.js

@@ -20,6 +20,6 @@ console.log(
 			isWebWorker: alasql.utils.isWebWorker,
 		},
 		null,
-		4
+		2
 	)
 );

test/test1965.js

@@ -0,0 +1,227 @@
+if (typeof exports === 'object') {
+	var assert = require('assert');
+	var alasql = require('..');
+}
+
+describe('Test UNION ALL with ORDER BY and LIMIT on each SELECT', function () {
+	const test = 'union_order_limit';
+
+	before(function () {
+		alasql('create database test' + test);
+		alasql('use test' + test);
+	});
+
+	after(function () {
+		alasql('drop database test' + test);
+	});
+
+	it('A) UNION ALL with ORDER BY and LIMIT using parentheses in UNION branch', function () {
+		// Create test data
+		alasql('CREATE TABLE temptable (subcategoryname STRING, totalamount FLOAT)');
+		alasql(`INSERT INTO temptable VALUES 
+('Bikes', 1000.5),
+('Components', 2000.75),
+('Clothing', 1500.25),
+('Accessories', 800.10),
+('Socks', 9556.37),
+('Helmets', 3000.00),
+('Gloves', 1200.50)`);
+
+		// SQL-99 compliant: Use parentheses on second SELECT for ORDER BY/LIMIT
+		// This works: plain SELECT, then UNION ALL with parenthesized SELECT
+		var sql = `
+SELECT subcategoryname, SUM(totalamount) AS sales
+FROM temptable
+WHERE subcategoryname IN ('Socks', 'Helmets', 'Components')
+GROUP BY subcategoryname
+UNION ALL
+(SELECT subcategoryname, SUM(totalamount) AS sales
+FROM temptable
+WHERE subcategoryname IN ('Accessories', 'Bikes', 'Gloves')
+GROUP BY subcategoryname
+ORDER BY sales ASC
+LIMIT 3)
+`;
+
+		var res = alasql(sql);
+
+		// Expected: 6 rows (3 from first + 3 from second with LIMIT 3)
+		var expected = [
+			{subcategoryname: 'Components', sales: 2000.75},
+			{subcategoryname: 'Socks', sales: 9556.37},
+			{subcategoryname: 'Helmets', sales: 3000},
+			{subcategoryname: 'Accessories', sales: 800.1},
+			{subcategoryname: 'Bikes', sales: 1000.5},
+			{subcategoryname: 'Gloves', sales: 1200.5},
+		];
+		assert.deepStrictEqual(
+			res,
+			expected,
+			'Should return correct rows with ORDER BY/LIMIT on second SELECT'
+		);
+
+		alasql('DROP TABLE temptable');
+	});
+
+	it('B) UNION with ORDER BY and LIMIT using parentheses', function () {
+		// Create test data
+		alasql('CREATE TABLE test2 (val INT)');
+		alasql('INSERT INTO test2 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10)');
+
+		// SQL-99 compliant: Use parentheses on second SELECT for ORDER BY/LIMIT
+		var sql = `
+SELECT val FROM test2
+WHERE val <= 5
+UNION
+(SELECT val FROM test2
+WHERE val >= 6
+ORDER BY val ASC
+LIMIT 2)
+`;
+
+		var res = alasql(sql);
+
+		// Expected: 7 rows (5 from first + 2 from second with LIMIT, UNION removes duplicates)
+		// Note: UNION doesn't guarantee order, so we sort the result for comparison
+		res.sort((a, b) => a.val - b.val);
+		var expected = [{val: 1}, {val: 2}, {val: 3}, {val: 4}, {val: 5}, {val: 6}, {val: 7}];
+		assert.deepStrictEqual(
+			res,
+			expected,
+			'Should return correct rows with UNION and LIMIT on second SELECT'
+		);
+
+		alasql('DROP TABLE test2');
+	});
+
+	it('C) Both SELECTs parenthesized with ORDER BY/LIMIT', function () {
+		// Test with both branches having parentheses
+		alasql('CREATE TABLE test3 (id INT, name STRING)');
+		alasql("INSERT INTO test3 VALUES (1,'Alice'),(2,'Bob'),(3,'Charlie'),(4,'David'),(5,'Eve')");
+
+		var sql = `
+(SELECT id, name FROM test3 ORDER BY id DESC LIMIT 2)
+UNION ALL
+(SELECT id, name FROM test3 ORDER BY id ASC LIMIT 2)
+`;
+
+		var res = alasql(sql);
+
+		var expected = [
+			{id: 5, name: 'Eve'},
+			{id: 4, name: 'David'},
+			{id: 1, name: 'Alice'},
+			{id: 2, name: 'Bob'},
+		];
+		assert.deepStrictEqual(res, expected, 'Both parenthesized SELECTs with ORDER BY/LIMIT');
+
+		alasql('DROP TABLE test3');
+	});
+
+	it('D) Parenthesized SELECT with ORDER BY DESC and LIMIT in UNION', function () {
+		// Test ORDER BY DESC
+		alasql('CREATE TABLE test4 (num INT)');
+		alasql('INSERT INTO test4 VALUES (10),(20),(30),(40),(50)');
+
+		var sql = `
+SELECT num FROM test4 WHERE num <= 30
+UNION ALL
+(SELECT num FROM test4 WHERE num > 30 ORDER BY num DESC LIMIT 1)
+`;
+
+		var res = alasql(sql);
+
+		var expected = [{num: 10}, {num: 20}, {num: 30}, {num: 50}];
+		assert.deepStrictEqual(res, expected, 'Parenthesized SELECT with ORDER BY DESC');
+
+		alasql('DROP TABLE test4');
+	});
+
+	it('E) UNION ALL with ORDER BY on both branches', function () {
+		// Test UNION ALL with ORDER BY on both first and second SELECT
+		alasql('CREATE TABLE test5 (letter STRING)');
+		alasql("INSERT INTO test5 VALUES ('a'),('b'),('c'),('d'),('e'),('f')");
+
+		var sql = `
+SELECT letter FROM test5 WHERE letter < 'c'
+UNION ALL
+(SELECT letter FROM test5 WHERE letter >= 'c' ORDER BY letter DESC LIMIT 2)
+`;
+
+		var res = alasql(sql);
+
+		var expected = [{letter: 'a'}, {letter: 'b'}, {letter: 'f'}, {letter: 'e'}];
+		assert.deepStrictEqual(
+			res,
+			expected,
+			'UNION ALL with ORDER BY DESC and LIMIT on second branch'
+		);
+
+		alasql('DROP TABLE test5');
+	});
+
+	it('F) EXCEPT with parenthesized ORDER BY/LIMIT', function () {
+		// Test EXCEPT operation with parentheses
+		alasql('CREATE TABLE test6a (num INT)');
+		alasql('CREATE TABLE test6b (num INT)');
+		alasql('INSERT INTO test6a VALUES (1),(2),(3),(4),(5)');
+		alasql('INSERT INTO test6b VALUES (3),(4)');
+
+		var sql = `
+SELECT num FROM test6a
+EXCEPT
+(SELECT num FROM test6b ORDER BY num ASC LIMIT 1)
+`;
+
+		var res = alasql(sql);
+
+		var expected = [{num: 1}, {num: 2}, {num: 4}, {num: 5}];
+		assert.deepStrictEqual(res, expected, 'EXCEPT with parenthesized ORDER BY/LIMIT');
+
+		alasql('DROP TABLE test6a');
+		alasql('DROP TABLE test6b');
+	});
+
+	it('G) INTERSECT with parenthesized ORDER BY/LIMIT', function () {
+		// Test INTERSECT operation with parentheses
+		alasql('CREATE TABLE test7a (num INT)');
+		alasql('CREATE TABLE test7b (num INT)');
+		alasql('INSERT INTO test7a VALUES (1),(2),(3),(4),(5)');
+		alasql('INSERT INTO test7b VALUES (3),(4),(5),(6)');
+
+		var sql = `
+(SELECT num FROM test7a WHERE num >= 3 ORDER BY num ASC LIMIT 2)
+INTERSECT
+SELECT num FROM test7b
+`;
+
+		var res = alasql(sql);
+
+		var expected = [{num: 3}, {num: 4}];
+		assert.deepStrictEqual(res, expected, 'INTERSECT with parenthesized ORDER BY/LIMIT');
+
+		alasql('DROP TABLE test7a');
+		alasql('DROP TABLE test7b');
+	});
+
+	it('H) ORDER BY after UNION applies to entire result (backwards compatibility)', function () {
+		// Test that ORDER BY after UNION still applies to the entire result
+		alasql('CREATE TABLE test8 (val INT)');
+		alasql('INSERT INTO test8 VALUES (30),(10),(20)');
+
+		var sql = `
+SELECT val FROM test8
+UNION ALL
+(SELECT val + 100 AS val FROM test8 ORDER BY val DESC LIMIT 2)
+ORDER BY val ASC
+`;
+
+		var res = alasql(sql);
+
+		// ORDER BY val ASC should apply to the combined result
+		var expected = [{val: 10}, {val: 20}, {val: 30}, {val: 130}, {val: 120}];
+		assert.deepStrictEqual(res, expected, 'ORDER BY after UNION applies to entire result');
+
+		alasql('DROP TABLE test8');
+	});
+});

test/test2414.js

@@ -129,11 +129,11 @@ describe('Test 2414 - UNION with parenthesized SELECT and ORDER BY', function ()
 		];
 
 		var res = alasql(
-			`(SELECT a FROM ? ORDER BY a LIMIT 2) UNION ALL (SELECT a FROM ? ORDER BY a DESC LIMIT 1)`,
+			`(SELECT b FROM ? ORDER BY a LIMIT 2) UNION ALL (SELECT b FROM ? ORDER BY a DESC LIMIT 1)`,
 			[data, data]
 		);
 
-		assert.deepEqual(res, [{a: 1}, {a: 2}]);
+		assert.deepEqual(res, [{b: 'x'}, {b: 'y'}, {b: 'w'}]);
 	});
 
 	it('H) UNION ALL with parenthesized ORDER BY', function () {