The parameter name '' has already been declared. Parameter names must be unique - node.js

Question

I have here an API created in NodeJS. When I run the API, it works on the first time, but if run it again its give me an error The parameter name Username has already been declared. Parameter names must be unique at Request.input. I checked other threads on how to fix this thing. Some answers that it needs to be cleared, but I think there is no function in NodeJS mssql library that clears parameter.(correct me if I'm wrong)
My code:
const res = require("express/lib/response")
const {sql,request} = require("../config/connection")
module.exports = {
checkExist: (data,callBack) => {
if(data.key == process.env.KEY) {
var username = data.username
var firstname = data.firstname
var middlename = data.middlename
var lastname = data.lastname
if(username == "" || firstname == "" || middlename == "" || lastname == "") {
return callBack("Invalid Input")
}
else {
request.input('Username', sql.VarChar(50), username);
request.input('FirstName', sql.VarChar(50), firstname);
request.input('MiddleName', sql.VarChar(50), middlename);
request.input('LastName', sql.VarChar(50), lastname);
request.output('Result', sql.Int);
request.execute('sp_INS_User').then(function(recordsets, returnValue, affected) {
if(recordsets.output.Result == -100) {
return callBack("Player Exist with different Username")
}
else if(recordsets.output.Result == -4) {
return callBack("Something went wrong while processing your request, please try again later.")
}
else {
if(recordsets.output.Result == 1000) {
return callBack(null,recordsets)
}
}
// console.dir(err);
}).catch(function(err) {
//return callBack(err)
return callBack("Something went wrong while processing your request, please try again later.")
});
}
}
else {
return callBack("Invalid Access")
}
}
}
My code in : ../config/connection/
const sql = require("mssql")
require("dotenv").config()
const sqlConfig = {
user: process.env.USER,
password: process.env.PASS,
database: process.env.DB_MAIN,
server: process.env.HOST,
pool: {
max: 10,
min: 0,
idleTimeoutMillis: 30000
},
options: {
encrypt:false,
trustServerCertificate: true
}
}
const con = sql.connect(sqlConfig).then(function() {
console.log(`Database connection successful!`);
}).catch(function(err) {
console.log(`Database connection ${err}!`);
});
const request = new sql.Request();
module.exports = {
sql,request
}

Answer 1

This looks like an issue of reusing the request object so the second time this function gets called, you're using the same request object that was previously used the first time this function was called. As such, you're registering duplicate names with request.input().
Apparently, you will need a new copy of const request = new sql.Request(); each time you want to use it because the error message is telling you that you can't repeat statements like request.input('Username',...) over and over on the same request object. So, export a function to get a new request object rather than exporting just one pre-made object.
You can do that like this:
../config/connection/
const sql = require("mssql")
require("dotenv").config()
const sqlConfig = {
user: process.env.USER,
password: process.env.PASS,
database: process.env.DB_MAIN,
server: process.env.HOST,
pool: {
max: 10,
min: 0,
idleTimeoutMillis: 30000
},
options: {
encrypt:false,
trustServerCertificate: true
}
}
const con = sql.connect(sqlConfig).then(function() {
console.log(`Database connection successful!`);
}).catch(function(err) {
console.log(`Database connection ${err}!`);
});
const getRequest = function() { return new sql.Request(); };
module.exports = {
sql, getRequest
};
And, your other code:
const res = require("express/lib/response")
const { sql, getRequest } = require("../config/connection")
module.exports = {
checkExist: (data, callBack) => {
const request = getRequest();
if (data.key == process.env.CAMS_INPLAY_KEY) {
var username = data.username
var firstname = data.firstname
var middlename = data.middlename
var lastname = data.lastname
if (username == "" || firstname == "" || middlename == "" || lastname == "") {
return callBack("Invalid Input")
} else {
request.input('Username', sql.VarChar(50), username);
request.input('FirstName', sql.VarChar(50), firstname);
request.input('MiddleName', sql.VarChar(50), middlename);
request.input('LastName', sql.VarChar(50), lastname);
request.output('Result', sql.Int);
request.execute('sp_INS_User').then(function(recordsets, returnValue, affected) {
if (recordsets.output.Result == -100) {
return callBack("Player Exist with different Username")
} else if (recordsets.output.Result == -4) {
return callBack(
"Something went wrong while processing your request, please try again later."
)
} else {
if (recordsets.output.Result == 1000) {
return callBack(null, recordsets)
}
}
// console.dir(err);
}).catch(function(err) {
//return callBack(err)
return callBack(
"Something went wrong while processing your request, please try again later."
)
});
}
} else {
return callBack("Invalid Access")
}
}
}