如何创建一个在Node.js和mysql中未使用的随机数

Question

I try to create a random number with following code

let randomnumber = (Math.random().toString().slice(-8))

And I will check if the mysql table has this random number, if doesn't, this number will be inserted into the table, if do, run the above code again, and check again. like this

await mysqlModel.checkNumberExit([randomnumber])
.then(async(results) => {
 if (results.length === 0) {
    //doesn't exist, do something
 } else {
   //exist, repeat until the random number doesn't exist
 }

Here is my question, how can I do this function efficiently, this way I am using is very low efficiency, any ideas?

Answer 1

You can use a function to generate and check:

function getRandomNumber() {
   let randomnumber = Math.floor(Math.random(1000,9999)*100000000);

    mysqlModel.find({"fieldName":randomnumber})
    .then(res => {
        if(!res) {
            //doesn't exist, do something
        }else{
            getRandomNumber();
        }
    }).catch(err => {
        //err
    });
}

call the function using:

getRandomNumber()