CODEWITHSUNDEEP
node.jstypescriptsqlitees6-promise
user10471818
user10471818

Reputation:

Promise returns undefined and data after

For some reason I am getting undefined before the actual data using the following code

async findOne(query: string, parameters: string): Promise<T> {
    const stmt: sqlite3.Statement = await this.db.prepare(query)
    const info: T = stmt.get(parameters)
    this.db.close()

    return info
}

const user = await respository.findOne('SELECT * FROM users WHERE id = ?', targetUser.id)
console.log(user)

The console log outputs undefined and a object after that, what is the reason for this?

Upvotes: 1

Views: 94

Answers (1)

MrfksIV
MrfksIV

Reputation: 930

Probably you will also need await here:

const info: T = await stmt.get(parameters);

From the documentation here it seems that .get is a classic callback function, so you will probably need to wrap it inside a Promise before using it with await.

Probably the same is true about this.db.prepare(query)? Checkout util.promisify from the standard node library if you don't want to do the promise wrapping yourself.

Also, you can't call an async function in open code. Try this:

(async () => {
   const user = await respository.findOne('SELECT * FROM users WHERE id = ?', targetUser.id)
})();

Hope this helps!

Upvotes: 1

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