I am attempting to insert data into an MS SQL server when a JSON Data API POST request is made.
var express = require('express');
var app = express();
var sql = require('mssql');
// Connection string parameters.
var sqlConfig = {
user: 'sa',
password: 'Forward@123',
server: '115.187.45.88',
database: 'Example',
requestTimeout: 1000,
options: {
"encrypt": false,
"enableArithAbort": true
}
}
// Initialize server and listen on http://localhost:8080/
var server = app.listen(8080, function () {
var host = server.address().address
var port = server.address().port
console.log("app listening at http://%s:%s/SendData", host, port)
});
app.use(
express.urlencoded({
extended: true
})
)
app.use(express.json())
app.post('/SendData', function (req, res) {
let data = '';
req.on('data', chunk => {
data += chunk;
})
req.on('end', () => {
var obj=JSON.parse(data);
for(var i=0;i<obj.length;i++){
console.log(obj[i]);
//write in db
var sqlString="INSERT INTO [dbo].[EmpTable] ([id],[fname],[lname]) VALUES ("+obj[i].id+",'"+obj[i].fname+"','"+obj[i].lname+"')";
console.log("sqlString ----- "+sqlString);
executeQuery(res, sqlString);
}
})
res.setHeader('Access-Control-Allow-Origin', '*');
return res.status(200).json({"Message":"Success!!!"});
});
var executeQuery = function(res,query){
sql.connect(sqlConfig,function(err){
if(err){
console.log("there is a database connection error -> "+err);
res.send(err);
}
else{
// create request object
var request = new sql.Request();
// query to the database
request.query(query,function(err,result){
if(err){
console.log("error while querying database -> "+err);
res.send(err);
}
else{
res.send(result);
sql.close();
}
});
}
});
}
The following error message is being displayed:
_http_outgoing.js:491 throw new Error('Can't set headers after they are sent.');
Error: Can't set headers after they are sent. at validateHeader (_http_outgoing.js:491:11) at ServerResponse.setHeader (_http_outgoing.js:498:3) at ServerResponse.header (E:\Node Workspace\node-post-api\node_modules\express\lib\response.js:771:10) at ServerResponse.send (E:\Node Workspace\node-post-api\node_modules\express\lib\response.js:170:12) at ServerResponse.json (E:\Node Workspace\node-post-api\node_modules\express\lib\response.js:267:15) at ServerResponse.send (E:\Node Workspace\node-post-api\node_modules\express\lib\response.js:158:21) at E:\Node Workspace\node-post-api\post-api-db-write.js:80:25 at _query (E:\Node Workspace\node-post-api\node_modules\mssql\lib\base\request.js:420:9) at Request.tds.Request.err [as userCallback] (E:\Node Workspace\node-post-api\node_modules\mssql\lib\tedious\request.js:479:15) at Request.callback (E:\Node Workspace\node-post-api\node_modules\tedious\lib\request.js:56:14)