Skip to content

Fix CSV export of missing properties #2934

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
yuexihuanchen wants to merge 2 commits into
base: develop
Choose a base branch
from
Open

Fix CSV export of missing properties #2934

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
576180d
Fix CSV export of missing properties (#369)
yuexihuanchen Oct 30, 2026
18f0d8f
Handle null CSV values as empty fields
yuexihuanchen Nov 1, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions src/830into.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -257,6 +257,10 @@ alasql.into.CSV = function (filename, opts, data, columns, cb) {
columns
.map(function (col) {
var s = d[col.columnid];
// Missing properties and null values both represent empty CSV fields.
if (s == null) {
s = '';
}
// escape the character wherever it appears in the field
if (opt.quote !== '') {
s = (s + '').replace(new RegExp('\\' + opt.quote, 'g'), opt.quote + opt.quote);
Expand Down
27 changes: 27 additions & 0 deletions test/test-csv-missing-properties.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,27 @@
if (typeof exports === 'object') {
var assert = require('assert');
var alasql = require('..');
}

describe('Test 369 - CSV export with missing properties', function () {
it('A) Export missing properties as empty fields', function () {
var data = [
{a: 1, b: 2, c: 3, d: 4},
{a: 5, b: 6},
];
var res = alasql('SELECT * INTO CSV({headers:true, utf8Bom:false}) FROM ?', [data]);
assert.deepStrictEqual(res, '"a";"b";"c";"d"\r\n1;2;3;4\r\n5;6;;\r\n');
});

it('B) Preserve an explicit undefined string', function () {
var data = [{a: 'undefined'}];
var res = alasql('SELECT * INTO CSV({headers:true, utf8Bom:false}) FROM ?', [data]);
assert.deepStrictEqual(res, '"a"\r\n"undefined"\r\n');
});

it('C) Export null as empty but preserve an explicit null string', function () {
var data = [{a: null, b: 'null'}];
var res = alasql('SELECT * INTO CSV({headers:true, utf8Bom:false}) FROM ?', [data]);
assert.deepStrictEqual(res, '"a";"b"\r\n;"null"\r\n');
});
});