Graphql Mysql - Get rows from a table in JSON Format - node.js

Question

I'm working on Backend with TypeGraphQL and NodePostGres.
User will pass database id and table name. I need to send data in JSON Format.
I have tried below code but it doesn't return anything nor does it throw any error.
Service:
import { Service } from 'typedi'
import { Client } from 'pg'
import { databases } from './db'
import { Payload } from './models'
#Service()
export class PayloadService {
fetchPayload(id: number, tableName: string): Payload {
const databaseCredentials = databases.find((d) => d.id && +d.id === id)
if (!databaseCredentials) throw new Error('Invalid ID!')
const client = new Client({
host: databaseCredentials.host,
port: +(databaseCredentials.port || 5432),
user: databaseCredentials.username,
password: databaseCredentials.password,
database: databaseCredentials.database,
ssl: {
rejectUnauthorized: false,
},
})
console.log('before client')
client.query("select * from pg_tables where schemaname='public'", (err, res) => {
if (err) {
console.log(err.stack)
} else {
console.log(res.rows[0])
}
console.log(`callback`)
})
console.log('after client')
return {
id,
data: [],
}
}
}
Resolver:
import { Arg, Query, Resolver } from 'type-graphql'
import { Inject } from 'typedi'
import { Payload } from './models'
import { PayloadService } from './services'
#Resolver(Payload)
export class PayloadResolver {
#Inject()
private PayloadService: PayloadService
#Query((returns) => Payload)
payload(#Arg('databaseId') databaseId: number, #Arg('tableName') tableName: string) {
return this.PayloadService.fetchPayload(databaseId, tableName)
}
}