node js and postgresql returning undefined-CodePudding

I am trying to select data from my database table and then print it in the console. whenever I try the console returns undefined.

const sql = await pool.query("SELECT * FROM users");
    for(rows in sql){
        console.log(rows.username)
    }

CodePudding user response：

Hey please know that query returns an array, so do this instead

const sql = await pool.query("SELECT * FROM users");
if(!sql.length) console.log("no data")
else{ for(let rows of sql){
        console.log(rows.username)
    }
}

CodePudding user response：

To get an array out of pool.query, you need to do the following:

const result = await pool.query("SELECT * FROM users");

const users = result.rows // get an array of users

If you want to get all the username from the users table, you can do:

const usernames = users.map((user) => user.username); // get an array of usernames