Prepared statements with Node-MSSQL - node.js

Question

I want to store API data in a SQL Server database with Node.js. It works already with a normal INSERT query as you see in the first code below.
server.route({
method: 'POST',
path: '/',
handler: async(request, h) => {
try {
await pool.query("INSERT INTO mytable(device,data,stationId,rssi,unix_timestamp) VALUES('"+request.payload.device+"','"+request.payload.data+"','"+request.payload.station+"',
'"+request.payload.rssi+"','"+request.payload.time+"')");
return h.response('Callback received').code(200);
}
catch (err) {
console.log("SQL Err", err.stack);
return 'Error';
}
}
});
Now my I want to improve the code a little bit to avoid SQL injection and to have a better overview.
Therefore I want to use prepared statements like described in this documentation: https://www.npmjs.com/package/mssql#prepared-statement
So far I've managed to do this here:
server.route({
method: 'POST',
path: '/',
handler: async(request, h) => {
const ps = new sql.PreparedStatement(pool)
try {
ps.input('device', sql.VarChar(10))
ps.input('data', sql.VarChar(24))
ps.input('station', sql.NChar(10))
ps.input('rssi', sql.Float)
ps.input('time', sql.Int)
await ps.prepare('INSERT INTO mytable(device,data,stationId,rssi,unix_timestamp) VALUES(#device,#data,#station,#rssi,#time)');
try {
await ps.execute(
{ device: request.payload.device },
{ data: request.payload.data },
{ station: request.payload.station },
{ rssi: request.payload.rssi },
{ time: request.payload.time }
)
} finally {
await ps.unprepare();
}
return h.response('Callback received').code(200);
}
catch (err) {
console.log("SQL Err", err.stack);
return 'Error';
}
}
});
And the following error occurs:
at Parser.emit (events.js:223:5)
at Parser.<anonymous> (C:\Users\AW\sqltest\node_modules\tedious\lib\token\token-stream-parser.js:37:14)
at Parser.emit (events.js:223:5)
at addChunk (C:\Users\AW\sqltest\node_modules\readable-stream\lib\_stream_readable.js:297:12)
at readableAddChunk (C:\Users\AW\sqltest\node_modules\readable-stream\lib\_stream_readable.js:279:11)
at Parser.Readable.push (C:\Users\AW\sqltest\node_modules\readable-stream\lib\_stream_readable.js:240:10)
at Parser.Transform.push (C:\Users\AW\sqltest\node_modules\readable-stream\lib\_stream_transform.js:139:32)
This is an example of the JSON data I get from the API:
{
"device":"887B53",
"data":"4660000000000062b4a8",
"station":"1B2C"
"rssi":"-123",
"time":"1585258718"
}
I hope someone can help me with that.

Answer 1

It appears that the error is occurring at the following line:
ps.input('station', sql.NChar(10))
I would debug the value that is being assigned here and see if it fits the schema, or if it's undefined.
Additionally on a side note if you are worried about readability and SQL injections, consider using an ORM such as Sequelize.