fix #1415: UNION not returning correct result (#1629)

AlaSQL · Feb 8, 2023 · 4287740 · 4287740
1 parent 09c53a4
commit 4287740
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Showing 2 changed files with 37 additions and 3 deletions.
diff --git a/src/38query.js b/src/38query.js
@@ -242,9 +242,16 @@ function queryfn3(query) {
 			ilen = nd.data.length;
 			for (var i = 0; i < ilen; i++) {
 				r = {};
-				jlen = Math.min(query.columns.length, nd.columns.length);
-				for (var j = 0; j < jlen; j++) {
-					r[query.columns[j].columnid] = nd.data[i][nd.columns[j].columnid];
+				if (query.columns.length) {
+					jlen = Math.min(query.columns.length, nd.columns.length);
+					for (var j = 0; j < jlen; j++) {
+						r[query.columns[j].columnid] = nd.data[i][nd.columns[j].columnid];
+					}
+				} else {
+					jlen = nd.columns.length;
+					for (var j = 0; j < jlen; j++) {
+						r[nd.columns[j].columnid] = nd.data[i][nd.columns[j].columnid];
+					}
 				}
 				ud.push(r);
 			}

diff --git a/test/test1415.js b/test/test1415.js
@@ -0,0 +1,27 @@
+if (typeof exports === 'object') {
+	var assert = require('assert');
+	var alasql = require('..');
+} else {
+	__dirname = '.';
+}
+
+describe('Test 1415 - UNION Expression with empty query columns bug', function () {
+	it('1. should not insert empty objects in results when using UNION Expression', function (done) {
+        var data1 = [
+            {a: 'abc'},
+            {a: 'xyz'}
+        ];
+        var data2 = [
+            {a: '123'},
+            {a: '987'}
+        ];
+
+		var res = alasql("SELECT * FROM :a UNION SELECT * FROM :b", {a: data1, b: data2});
+		assert.deepEqual(res, [{a: '123'}, {a: '987'}, { a: 'abc'}, {a: 'xyz'}]);
+
+        var res = alasql("SELECT * FROM @[{x: true}, {x: 3}] UNION SELECT * FROM @[{x: false}, {x: 9}]");
+		assert.deepEqual(res, [{x: false}, {x: 9}, {x: true}, {x: 3}]);
+
+		done();
+	});
+});