Try this one…
import wixUsers from 'wix-users';
import wixData from 'wix-data';
$w.onReady(function () {
let user = wixUsers.currentUser;
let userId = user.id; console.log(userId);
wixData.query("Members/PrivateMembersData")
.eq("_id", wixUsers.currentUser.id)
.find()
.then((results) => {console.log(results.items[0])
$w('#input7').value = results.items[0].loginEmail;
$w('#input5').value = results.items[0].firstName;
$w('#input6').value = results.items[0].lastName;
});
$w('#button1').onClick(()=>{
$w('#dataset1').setFieldValue('firstName', $w('#input5').value);
$w('#dataset1').setFieldValue('lastName', $w('#input6').value);
$w('#dataset1').setFieldValue('eMail', $w('#input7').value);
});
$w('#dataset1').onReady(()=>{
$w('#dataset1').save()
.then((item)=>{let fieldValue = item.fieldName; console.log(fieldValue);})
.catch((err)=>{console.log(err);});
});
});
EDIT: You perhaps also should consider to use → setFieldValues instead, which gives you the ability to set multiple values and save them at once…
$w("#myDataset").setFieldValues({
'firstName', $w('#input5').value,
'lastName', $w('#input6').value,
'eMail', $w('#input7').value
});