Fix SERIAL columns to respect explicitly provided values including NULL

src/60createtable.js

@@ -353,7 +353,10 @@ yy.CreateTable.prototype.execute = function (databaseid, params, cb) {
 		for (var columnid in table.identities) {
 			var ident = table.identities[columnid];
 			//			console.log(ident);
-			r[columnid] = ident.value;
+			// Only auto-assign identity value if not explicitly provided
+			if (typeof r[columnid] === 'undefined') {
+				r[columnid] = ident.value;
+			}
 			//			console.log(ident);
 		}
 		//console.log(270,r);
@@ -417,7 +420,13 @@ yy.CreateTable.prototype.execute = function (databaseid, params, cb) {
 			for (var columnid in table.identities) {
 				var ident = table.identities[columnid];
 				//			console.log(ident);
-				ident.value += ident.step;
+				// Only increment if we used the auto-generated value
+				// If user provided explicit value >= current counter, update counter
+				if (typeof r[columnid] !== 'undefined' && r[columnid] >= ident.value) {
+					ident.value = r[columnid] + ident.step;
+				} else {
+					ident.value += ident.step;
+				}
 				//			console.log(ident);
 			}
 

test/test895.js

@@ -0,0 +1,115 @@
+if (typeof exports === 'object') {
+	var assert = require('assert');
+	var alasql = require('..');
+}
+
+describe('Test 895 - SERIAL type should not overwrite explicitly provided values', function () {
+	const test = '895';
+
+	before(function () {
+		alasql('create database test' + test);
+		alasql('use test' + test);
+	});
+
+	after(function () {
+		alasql('drop database test' + test);
+	});
+
+	it('A) SERIAL column should auto-increment when not provided', function () {
+		alasql('CREATE TABLE test_serial (id serial, name varchar(50))');
+		alasql('INSERT INTO test_serial (name) VALUES ("first")');
+		alasql('INSERT INTO test_serial (name) VALUES ("second")');
+		alasql('INSERT INTO test_serial (name) VALUES ("third")');
+		var res = alasql('SELECT * FROM test_serial ORDER BY id');
+		assert.deepEqual(res, [
+			{id: 1, name: 'first'},
+			{id: 2, name: 'second'},
+			{id: 3, name: 'third'},
+		]);
+	});
+
+	it('B) SERIAL column should accept explicitly provided value', function () {
+		alasql('CREATE TABLE test_serial2 (id serial, name varchar(50))');
+		alasql('INSERT INTO test_serial2 (id, name) VALUES (10, "first")');
+		alasql('INSERT INTO test_serial2 (id, name) VALUES (20, "second")');
+		alasql('INSERT INTO test_serial2 (id, name) VALUES (30, "third")');
+		var res = alasql('SELECT * FROM test_serial2 ORDER BY id');
+		assert.deepEqual(res, [
+			{id: 10, name: 'first'},
+			{id: 20, name: 'second'},
+			{id: 30, name: 'third'},
+		]);
+	});
+
+	it('C) SERIAL column should accept explicitly provided value even if lower than counter', function () {
+		alasql('CREATE TABLE test_serial3 (id serial, name varchar(50))');
+		// Insert with auto-increment first
+		alasql('INSERT INTO test_serial3 (name) VALUES ("auto1")');
+		alasql('INSERT INTO test_serial3 (name) VALUES ("auto2")');
+		alasql('INSERT INTO test_serial3 (name) VALUES ("auto3")');
+		// Now insert with explicit ID that is higher than counter
+		alasql('INSERT INTO test_serial3 (id, name) VALUES (100, "explicit")');
+		var res = alasql('SELECT * FROM test_serial3 ORDER BY id');
+		assert.deepEqual(res, [
+			{id: 1, name: 'auto1'},
+			{id: 2, name: 'auto2'},
+			{id: 3, name: 'auto3'},
+			{id: 100, name: 'explicit'},
+		]);
+	});
+
+	it('D) SERIAL with mixed auto and explicit values', function () {
+		alasql('CREATE TABLE test_serial4 (id serial, name varchar(50))');
+		alasql('INSERT INTO test_serial4 (id, name) VALUES (5, "explicit5")');
+		// After explicit insert of 5, counter advances to 6
+		alasql('INSERT INTO test_serial4 (name) VALUES ("auto")'); // Should be 6
+		alasql('INSERT INTO test_serial4 (id, name) VALUES (10, "explicit10")');
+		// After explicit insert of 10, counter advances to 11
+		alasql('INSERT INTO test_serial4 (name) VALUES ("auto2")'); // Should be 11
+		var res = alasql('SELECT * FROM test_serial4 ORDER BY id');
+		assert.deepEqual(res, [
+			{id: 5, name: 'explicit5'},
+			{id: 6, name: 'auto'},
+			{id: 10, name: 'explicit10'},
+			{id: 11, name: 'auto2'},
+		]);
+	});
+
+	it('E) Bulk insert with explicit SERIAL values', function () {
+		alasql('CREATE TABLE test_serial5 (id serial, name varchar(50))');
+		alasql('INSERT INTO test_serial5 (id, name) VALUES (4, "item4"), (8, "item8"), (12, "item12")');
+		var res = alasql('SELECT * FROM test_serial5 ORDER BY id');
+		assert.deepEqual(res, [
+			{id: 4, name: 'item4'},
+			{id: 8, name: 'item8'},
+			{id: 12, name: 'item12'},
+		]);
+	});
+
+	it('F) Re-inserting data after truncate with explicit IDs', function () {
+		alasql('CREATE TABLE test_serial6 (id serial, name varchar(50))');
+		// Initial data
+		alasql('INSERT INTO test_serial6 (name) VALUES ("first"), ("second"), ("third")');
+		var res1 = alasql('SELECT * FROM test_serial6 ORDER BY id');
+		assert.deepEqual(res1, [
+			{id: 1, name: 'first'},
+			{id: 2, name: 'second'},
+			{id: 3, name: 'third'},
+		]);
+
+		// Simulate the flush scenario from the issue
+		alasql('DELETE FROM test_serial6'); // Delete all
+
+		// Re-insert with explicit IDs (simulating data from backend storage)
+		alasql('INSERT INTO test_serial6 (id, name) VALUES (4, "item4")');
+		alasql('INSERT INTO test_serial6 (id, name) VALUES (7, "item7")');
+		alasql('INSERT INTO test_serial6 (id, name) VALUES (9, "item9")');
+
+		var res2 = alasql('SELECT * FROM test_serial6 ORDER BY id');
+		assert.deepEqual(res2, [
+			{id: 4, name: 'item4'},
+			{id: 7, name: 'item7'},
+			{id: 9, name: 'item9'},
+		]);
+	});
+});