how to create callback functions properly in this case.
how to wait until query executing the result. This is the code snippet:
app.post('/validate', urlencodedParser, function (req, res) {
var data = [
{username:req.body.user, password:req.body.pwd}
];
var disp = function (data,res, callback) {
return callback(data,res);
}
console.log(disp(data,res, LoginCheck));
});
var LoginCheck = function (data,res) {
var dbresult = [];
var client = new pg.Client(conString);
client.connect();
var query = client.query("SELECT * FROM employee_details");
query.on("row", function (row, result) {
result.addRow(row);
});
query.on("end", function (result) {
dbresult=result.rows;
console.log(dbresult);
return dbresult;
});
}
You need only one callback function
app.post('/validate', urlencodedParser, function (req, res) {
var data = [
{username:req.body.user, password:req.body.pwd}
];
/* var disp = function (data,res, callback) {
return callback(data,res,callback2);
}
console.log(disp(data,res, LoginCheck));
*/
LoginCheck(data,res, function(result){
if(result){
//do whatever you want
console.log(result)
}
})
});
var LoginCheck = function (data,res,callback2) {
var dbresult = [];
var client = new pg.Client(conString);
client.connect();
var query = client.query("SELECT * FROM employee_details");
query.on("row", function (row, result) {
result.addRow(row);
});
query.on("end", function (result) {
dbresult=result.rows;
console.log(dbresult);
return callback2(dbresult);
});
}