Allow nested subqueries for IN clause to fix #847 (#2187)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: mathiasrw <[email protected]>
Co-authored-by: Mathias Wulff <[email protected]>

Author: Copilot

src/40select.js

@@ -390,6 +390,15 @@ yy.Select = class Select {
 		query.queriesfn = this.queries.map(function (q) {
 			var nq = q.compile(query.database.databaseid);
 			nq.query.modifier = 'RECORDSET';
+			// If the nested query has its own queries, ensure they're compiled too
+			// This handles nested subqueries properly
+			if (q.queries && q.queries.length > 0) {
+				nq.query.queriesfn = q.queries.map(function (qq) {
+					var nnq = qq.compile(query.database.databaseid);
+					nnq.query.modifier = 'RECORDSET';
+					return nnq;
+				});
+			}
 			return nq;
 		});
 	}

src/alasqlparser.jison

@@ -1582,8 +1582,16 @@ Op
 	| Expression CondOp AllSome LPAR Select RPAR
 		{
 			if(!yy.queries) yy.queries = [];
-			$$ = new yy.Op({left:$1, op:$2 , allsome:$3, right:$5, queriesidx: yy.queries.length});
+			// Collect any nested queries that belong to this SELECT
+			var nestedQueries = yy.queries.slice();
+			yy.queries = [];
+			// Assign nested queries to the SELECT
+			if(nestedQueries.length > 0) {
+				$5.queries = nestedQueries;
+			}
+			// Now add this SELECT to parent queries
 			yy.queries.push($5);
+			$$ = new yy.Op({left:$1, op:$2 , allsome:$3, right:$5, queriesidx: yy.queries.length - 1});
 		}
 
 	| Expression CondOp AllSome LPAR ExprList RPAR
@@ -1639,15 +1647,31 @@ Op
 	| Expression IN LPAR Select RPAR
 		{
 			if(!yy.queries) yy.queries = [];
-			$$ = new yy.Op({left: $1, op:'IN', right:$4, queriesidx: yy.queries.length});
+			// Collect any nested queries that belong to this SELECT
+			var nestedQueries = yy.queries.slice();
+			yy.queries = [];
+			// Assign nested queries to the SELECT
+			if(nestedQueries.length > 0) {
+				$4.queries = nestedQueries;
+			}
+			// Now add this SELECT to parent queries
 			yy.queries.push($4);
+			$$ = new yy.Op({left: $1, op:'IN', right:$4, queriesidx: yy.queries.length - 1});
 		}
 
 	| Expression NOT IN LPAR Select RPAR
 		{
 			if(!yy.queries) yy.queries = [];
-			$$ = new yy.Op({left: $1, op:'NOT IN', right:$5, queriesidx: yy.queries.length});
+			// Collect any nested queries that belong to this SELECT
+			var nestedQueries = yy.queries.slice();
+			yy.queries = [];
+			// Assign nested queries to the SELECT
+			if(nestedQueries.length > 0) {
+				$5.queries = nestedQueries;
+			}
+			// Now add this SELECT to parent queries
 			yy.queries.push($5);
+			$$ = new yy.Op({left: $1, op:'NOT IN', right:$5, queriesidx: yy.queries.length - 1});
 		}
 
 	| Expression IN LPAR ExprList RPAR

src/alasqlparser.js

@@ -0,0 +1,73 @@
+// Test for nested subqueries - Issue: Nested SubQueries do not work as expected
+if (typeof exports === 'object') {
+	var assert = require('assert');
+	var alasql = require('..');
+}
+
+describe('Test 847 - Nested Subqueries', function () {
+	before(function () {
+		alasql(`
+			DROP TABLE IF EXISTS cities;
+			DROP TABLE IF EXISTS countries;
+			DROP TABLE IF EXISTS population;
+
+			CREATE TABLE cities (city string, population number);
+			INSERT INTO cities VALUES ('Rome',2863223), ('Paris',2249975), ('Berlin',3517424), ('Madrid',3041579),('Easingwold',4627);
+
+			CREATE TABLE countries (name string, population number, city string);
+			INSERT INTO countries VALUES ('Italy', 89764679009, 'Rome'), ('France', 165247191, 'Paris'), ('Germany', 346186257, 'Berlin');
+
+			CREATE TABLE population (number int);
+			INSERT INTO population VALUES (89764679009), (165247191);
+		`);
+	});
+
+	after(function () {
+		alasql(`
+			DROP TABLE IF EXISTS cities;
+			DROP TABLE IF EXISTS countries;
+			DROP TABLE IF EXISTS population;
+		`);
+	});
+
+	it('1. Nested subqueries in IN clause should work', function () {
+		var result = alasql(
+			'SELECT * FROM cities WHERE city IN (SELECT DISTINCT city FROM countries WHERE population IN (SELECT DISTINCT number from population))'
+		);
+
+		assert.equal(result.length, 2, 'Should return 2 cities');
+		assert.equal(result[0].city, 'Rome', 'First city should be Rome');
+		assert.equal(result[1].city, 'Paris', 'Second city should be Paris');
+	});
+
+	it('2. Single level subquery should still work', function () {
+		var result = alasql('SELECT * FROM cities WHERE city IN (SELECT city FROM countries)');
+
+		assert.equal(result.length, 3, 'Should return 3 cities');
+	});
+
+	it('3. Triple nested subqueries should work', function () {
+		alasql(`
+			CREATE TABLE level3 (val int);
+			INSERT INTO level3 VALUES (89764679009);
+		`);
+
+		var result = alasql(
+			'SELECT * FROM cities WHERE city IN (SELECT DISTINCT city FROM countries WHERE population IN (SELECT DISTINCT number from population WHERE number IN (SELECT val FROM level3)))'
+		);
+
+		assert.equal(result.length, 1, 'Should return 1 city');
+		assert.equal(result[0].city, 'Rome', 'City should be Rome');
+
+		alasql('DROP TABLE IF EXISTS level3');
+	});
+
+	it('4. Nested subqueries with NOT IN should work', function () {
+		var result = alasql(
+			'SELECT * FROM cities WHERE city NOT IN (SELECT DISTINCT city FROM countries WHERE population NOT IN (SELECT DISTINCT number from population))'
+		);
+
+		// Should return cities that are either not in countries, or in countries with population in the population table
+		assert(result.length > 0, 'Should return some results');
+	});
+});