Currently, I am utilizing the NodeJS postgresql client to retrieve data, iterate through it and provide an output. To accomplish this, I have integrated ExpressJS with the postgresql client.
This is a snippet of my code
var main_data = an array containing data
var user_info = {}
for (var key in result.rows) {
var user = main_data[key].user
client.query('SELECT name,age,address FROM users WHERE user_id = $1 LIMIT 1;' , [user], function(queryErr, result){
var return_data = result.rows[0]
user_info.name = return_data.name
user_info.gender = return_data.gender
user_info.address = return_data.address
main_data[key].user_info = user_info
})
}
done()
res.json(main_data)
return
Unfortunately, upon running the code, the desired output is not obtained. The userinfo does not get added to the main_data as intended but simply displays the main_data variable from the beginning of the code.
This issue cannot be solved by following the recommended duplicate Given that the function lies within a for loop, I cannot execute the response call once the function completes. It is necessary to wait until the entire loop finishes, which could involve over 1000 iterations before making the response call.
Can anyone advise on how to achieve this? What mistakes am I making and how can they be rectified? Thank you in advance