Fix SELECT for columns from JOINed inline data to close #1985 (#2339)

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

Author: Copilot

src/424select.js

@@ -244,15 +244,33 @@ yy.Select.prototype.compileSelect1 = function (query, params) {
 								"']).length;i++)" +
 								' for(var k=0;k<cols.length;k++){if (!r.hasOwnProperty(i)) r[i]={}; r[i][colas[k]]=w[i][cols[k]];}';
 						} else {
-							ss.push(
-								"'" +
-									escapeq(col.as || col.columnid) +
-									"':p['" +
-									tbid +
-									"']['" +
-									col.columnid +
-									"']"
-							);
+							// For JOINs with inline data where column table is unknown, search all tables
+							var needsRuntimeResolution =
+								!col.tableid &&
+								query.sources.length > 1 &&
+								(!query.defcols[col.columnid] || query.defcols[col.columnid] === '-');
+
+							if (needsRuntimeResolution) {
+								// Try each table until column is found
+								var aliases = Object.keys(query.aliases);
+								var searchExpr = aliases
+									.map(function (alias) {
+										return "p['" + alias + "']['" + col.columnid + "']";
+									})
+									.join(' ?? ');
+
+								ss.push("'" + escapeq(col.as || col.columnid) + "':(" + searchExpr + ')');
+							} else {
+								ss.push(
+									"'" +
+										escapeq(col.as || col.columnid) +
+										"':p['" +
+										tbid +
+										"']['" +
+										col.columnid +
+										"']"
+								);
+							}
 						}
 					}
 				} else {

test/test1985.js

@@ -0,0 +1,96 @@
+if (typeof exports === 'object') {
+	var assert = require('assert');
+	var alasql = require('..');
+}
+
+describe('Test 1985 - SELECT field on joined tables gives unexpected undefined', function () {
+	const test = '1985';
+
+	it('A) SELECT * works correctly', function () {
+		const users = [{UserId: '1', UserName: 'User'}];
+		const orders = [{UserId: '1', Text: 'Order text'}];
+
+		const expected = alasql(
+			`
+  SELECT *
+  FROM ? u 
+  JOIN ? o 
+  ON u.UserId = o.UserId`,
+			[users, orders]
+		);
+
+		// Should have all fields
+		assert.deepEqual(expected, [
+			{
+				UserId: '1',
+				UserName: 'User',
+				Text: 'Order text',
+			},
+		]);
+	});
+
+	it('B) SELECT specific fields should not return undefined', function () {
+		const users = [{UserId: '1', UserName: 'User'}];
+		const orders = [{UserId: '1', Text: 'Order text'}];
+
+		const result = alasql(
+			`
+  SELECT UserName, Text 
+  FROM ? u 
+  JOIN ? o 
+  ON u.UserId = o.UserId`,
+			[users, orders]
+		);
+
+		// Both fields should be defined
+		assert.deepEqual(result, [
+			{
+				UserName: 'User',
+				Text: 'Order text',
+			},
+		]);
+	});
+
+	it('C) SELECT single field from second table', function () {
+		const users = [{UserId: '1', UserName: 'User'}];
+		const orders = [{UserId: '1', Text: 'Order text'}];
+
+		const result = alasql(
+			`
+  SELECT Text 
+  FROM ? u 
+  JOIN ? o 
+  ON u.UserId = o.UserId`,
+			[users, orders]
+		);
+
+		// Text field should be defined
+		assert.deepEqual(result, [
+			{
+				Text: 'Order text',
+			},
+		]);
+	});
+
+	it('D) SELECT with table aliases', function () {
+		const users = [{UserId: '1', UserName: 'User'}];
+		const orders = [{UserId: '1', Text: 'Order text'}];
+
+		const result = alasql(
+			`
+  SELECT u.UserName, o.Text 
+  FROM ? u 
+  JOIN ? o 
+  ON u.UserId = o.UserId`,
+			[users, orders]
+		);
+
+		// Both fields should be defined
+		assert.deepEqual(result, [
+			{
+				UserName: 'User',
+				Text: 'Order text',
+			},
+		]);
+	});
+});