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VisualizaçõesMissing updated record when using map function
This is my code for update many records with mongodb.
const nfts = await waxModel.find();
console.log(nfts.length) // -> 121
// Option 1: using map()
nfts.map(async nft => {
nft.trait_attribute = null;
await nft.save();
});
// Option 2: using loop
for (let i = 0; i < nfts.length; i++) {
nfts[i].trait_attribute = null;
await nfts[i].save();
}
- This is my DB, no recored have trait_attribute: null:
- This is the first result when I use map(), only have 2 records:
- And this is the second result when I use for loop:
I don't know that is the problem. In my previous question: I know map methods don't handle the asynchronous function but it's still have full records not missing many updated records as now. Thank for your attention.
·
Juan Pablo Isaza
1 Respostas
Responde à pergunta0
It looks like your code doesn't handle race conditions well.
The first option saves every nft simultaneously whilst the second one saves them one at a time. A more readable way to do that would be using a for-of loop:
for (const nft of nfts) {
nft.trait_attribute = null;
await nft.save();
}
·
Juan Pablo Isaza
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