JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/xlsx/0.8.0/xlsx.full.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/alasql@0.4/dist/alasql.js"></script>
<xmp id="output"></xmp>

JavaScript

print('I would expect to get [] but I get [ {"a": 1} ]:')

alasql('CREATE TABLE R (a number)');
alasql('CREATE TABLE S (b number)');
alasql.tables.R.data = [ {a: 1}, {a: null} ];
alasql.tables.S.data = [ {b: null} ];
var res = alasql('select a from R where a not in (select b from S)');
// expected: res = []
// alasql:   res = [ {"a": 1} ]

print(res)
	






function print(x){
    document.getElementById('output').textContent += JSON.stringify(x,  null, '\t')+"\n";
}
print('AlaSQL v'+alasql.version)