How to send query parameter values through script in postman for GET API request

Question

I want to execute a Get request with different parameter values

eg:-

localhost:8080//employee/employee-details?sort_by={{sort_by}}&sort_order=ASC

in place of "{{sort_by}}" i want to execute with different values as employee_id, employee_name, department, salary ..etc.,

Answer 1

You can pass the parameter by collection variable(type is array)

Collection Variables

sortKeys : ["employee_id", "employee_name", "department", "salary"]
sortKey  : employee_id

URL

GET http://localhost:8080/employee/employee-details?sort_by={{sortKey}}

Pre-script

let sortKeys = JSON.parse(pm.collectionVariables.get("sortKeys"));
pm.collectionVariables.set("sortKey", sortKeys.shift())
pm.collectionVariables.set("sortKeys", JSON.stringify(sortKeys));
if (sortKeys.length > 0){
    postman.setNextRequest("Get Employee"); // <- GET Request Name
}

Post-response :(in old version test script)

// Expected values for the first employee ID based on the sort key
const expectedFirstIds = {
    employee_id: 1,
    employee_name: 4,
    department: 3,
    salary: 5
};

// Get the current sort key from the collection variable
const sortKey = pm.collectionVariables.get("sortKey");

const responseJson = pm.response.json();
// Check if the first employee ID matches the expected value
pm.test(`The first employee ID for sort key ${sortKey} is correct`, function () {
    pm.expect(responseJson[0].employee_id).to.eql(expectedFirstIds[sortKey]);
});

Demo

mock-server Save as mock-server.js

const express = require('express');
const app = express();
const port = 8080;

const employees = [
  { employee_id: 1, employee_name: 'David', department: 'HR', salary: 120000 },
  { employee_id: 2, employee_name: 'Eve', department: 'IT', salary: 60000 },
  { employee_id: 3, employee_name: 'Charlie', department: 'Finance', salary: 55000 },
  { employee_id: 4, employee_name: 'Alice', department: 'IT', salary: 70000 },
  { employee_id: 5, employee_name: 'Bob', department: 'HR', salary: 52000 }
];

app.get('/employee/employee-details', (req, res) => {
  const sortBy = req.query.sort_by;
  const validSortFields = ['employee_id', 'employee_name', 'department', 'salary'];

  if (!validSortFields.includes(sortBy)) {
    return res.status(400).send({ error: `Invalid sort_by field. Valid fields are: ${validSortFields.join(', ')}` });
  }

  const sortedEmployees = [...employees].sort((a, b) => {
    if (a[sortBy] < b[sortBy]) return -1;
    if (a[sortBy] > b[sortBy]) return 1;
    return 0;
  });

  res.json(sortedEmployees);
});

app.listen(port, () => {
  console.log(`Server running at http://localhost:${port}/`);
});

Install dependency and run it

npm install express
node mock-server.js

Verify API

http://localhost:8080/employee/employee-details?sort_by=employee_id

http://localhost:8080/employee/employee-details?sort_by=employee_name

http://localhost:8080/employee/employee-details?sort_by=department

http://localhost:8080/employee/employee-details?sort_by=salary

Single Request

Import this collection

{
    "info": {
        "_postman_id": "ef4bd661-b94e-4099-b512-a2268c5d5fc5",
        "name": "1-demo",
        "schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json",
        "_exporter_id": "1826150"
    },
    "item": [
        {
            "name": "Get Employee",
            "event": [
                {
                    "listen": "test",
                    "script": {
                        "exec": [
                            "// Expected values for the first employee ID based on the sort key\r",
                            "const expectedFirstIds = {\r",
                            "    employee_id: 1,\r",
                            "    employee_name: 4,\r",
                            "    department: 3,\r",
                            "    salary: 5\r",
                            "};\r",
                            "\r",
                            "// Get the current sort key from the collection variable\r",
                            "const sortKey = pm.collectionVariables.get(\"sortKey\");\r",
                            "\r",
                            "const responseJson = pm.response.json();\r",
                            "// Check if the first employee ID matches the expected value\r",
                            "pm.test(`The first employee ID for sort key ${sortKey} is correct`, function () {\r",
                            "    pm.expect(responseJson[0].employee_id).to.eql(expectedFirstIds[sortKey]);\r",
                            "});"
                        ],
                        "type": "text/javascript",
                        "packages": {}
                    }
                },
                {
                    "listen": "prerequest",
                    "script": {
                        "exec": [
                            "let sortKeys = JSON.parse(pm.collectionVariables.get(\"sortKeys\"));\r",
                            "pm.collectionVariables.set(\"sortKey\", sortKeys.shift())\r",
                            "pm.collectionVariables.set(\"sortKeys\", JSON.stringify(sortKeys));\r",
                            "if (sortKeys.length > 0){\r",
                            "    postman.setNextRequest(\"Get Employee\"); // <- GET Request Name\r",
                            "}"
                        ],
                        "type": "text/javascript",
                        "packages": {}
                    }
                }
            ],
            "request": {
                "method": "GET",
                "header": [],
                "url": {
                    "raw": "http://localhost:8080/employee/employee-details?sort_by={{sortKey}}",
                    "protocol": "http",
                    "host": [
                        "localhost"
                    ],
                    "port": "8080",
                    "path": [
                        "employee",
                        "employee-details"
                    ],
                    "query": [
                        {
                            "key": "sort_by",
                            "value": "{{sortKey}}"
                        }
                    ]
                }
            },
            "response": []
        }
    ],
    "event": [
        {
            "listen": "prerequest",
            "script": {
                "type": "text/javascript",
                "exec": [
                    ""
                ]
            }
        },
        {
            "listen": "test",
            "script": {
                "type": "text/javascript",
                "exec": [
                    ""
                ]
            }
        }
    ],
    "variable": [
        {
            "key": "sortKeys",
            "value": "[\"employee_id\", \"employee_name\", \"department\", \"salary\"]",
            "type": "string"
        },
        {
            "key": "sortKey",
            "value": "employee_id",
            "type": "string"
        }
    ]
}

After Import

Run Collection

Result

Looping call "Get Employee" request by sortKeys from "employee_id" -> "employee_name" ->"department" to "salary"