Mixing
Firebase Realtime Database and HTTP requests: complex queries over multiple axes
1
I have the following code to retrieve data with timestamps within the given dates and hour ranges:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
return snapshot.ref.orderByKey().startAt(`${hourFrom}`).endAt(`${hourTo}`).once('value').then( (s) => {
console.log(s.val());
return res.status(200).send(s.val());
});
})
});
The database in question looks like follows:
That is, for easy retrieval, I first bucket the items by date, then within the date -- by hour. So, 12 in the above image is 12:00PM.
Now, Firebase does not allow chaining two orderByKey()s, that is why I am trying to query first by date, and then, given a snapshot, trying to iterate over the children using snapshot.forEach(child), like so:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
acc= ;
snapshot.forEach( (day) => {
day.forEach((hour) => {
console.log("This: " + hour.key);
if (hourFrom <= hour.key && hour.key <= hourTo)
hour.forEach((meal) => {
acc.push(meal.val());
});
});
});
return res.status(200).send(acc);
})
});
My question is, it is still possible to somehow chain the queries along the two axes, or an approach similar to the second code snippet is the only way to go?
javascript
firebase firebase-realtime-database asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
add a comment |
1
I have the following code to retrieve data with timestamps within the given dates and hour ranges:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
return snapshot.ref.orderByKey().startAt(`${hourFrom}`).endAt(`${hourTo}`).once('value').then( (s) => {
console.log(s.val());
return res.status(200).send(s.val());
});
})
});
The database in question looks like follows:
That is, for easy retrieval, I first bucket the items by date, then within the date -- by hour. So, 12 in the above image is 12:00PM.
Now, Firebase does not allow chaining two orderByKey()s, that is why I am trying to query first by date, and then, given a snapshot, trying to iterate over the children using snapshot.forEach(child), like so:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
acc= ;
snapshot.forEach( (day) => {
day.forEach((hour) => {
console.log("This: " + hour.key);
if (hourFrom <= hour.key && hour.key <= hourTo)
hour.forEach((meal) => {
acc.push(meal.val());
});
});
});
return res.status(200).send(acc);
})
});
My question is, it is still possible to somehow chain the queries along the two axes, or an approach similar to the second code snippet is the only way to go?
javascript
firebase firebase-realtime-database asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
There are two possible meanings here. Do you want meals fromdayFromathourFromuntildayToathourTo? Or do you want meals on for each day fromdayFromuntildayTo, betweenhourFromandhourTo?
– Frank van Puffelen
Nov 19 '18 at 17:56
@FrankvanPuffelen: The second code snippet gets the job done, and indeed it is the second meaning -- the so-called "orthogonal range reporting", in CS parlance.
– Ilonpilaaja
Nov 19 '18 at 18:01
1
That looks like it's the second option from my first comment. There is no way to query two properties in a single query, and from a quick scan it seems like you also can't combine these with a single synthetic property. It looks like you'll need a query for each day at least, unless there are limits that you didn't share (e.g. the time ranges are a fixed, limited number). Also see stackoverflow.com/questions/26700924/…
– Frank van Puffelen
Nov 19 '18 at 18:04
Now I see I indeed used the approach "filter first at server, and the rest at client" approach in my Android code, first binding to a query and additionally filtering inonChildAddedmethod. As for this question, I am using the second snippet, then.
– Ilonpilaaja
Nov 19 '18 at 18:08
add a comment |
1
1
1
I have the following code to retrieve data with timestamps within the given dates and hour ranges:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
return snapshot.ref.orderByKey().startAt(`${hourFrom}`).endAt(`${hourTo}`).once('value').then( (s) => {
console.log(s.val());
return res.status(200).send(s.val());
});
})
});
The database in question looks like follows:
That is, for easy retrieval, I first bucket the items by date, then within the date -- by hour. So, 12 in the above image is 12:00PM.
Now, Firebase does not allow chaining two orderByKey()s, that is why I am trying to query first by date, and then, given a snapshot, trying to iterate over the children using snapshot.forEach(child), like so:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
acc= ;
snapshot.forEach( (day) => {
day.forEach((hour) => {
console.log("This: " + hour.key);
if (hourFrom <= hour.key && hour.key <= hourTo)
hour.forEach((meal) => {
acc.push(meal.val());
});
});
});
return res.status(200).send(acc);
})
});
My question is, it is still possible to somehow chain the queries along the two axes, or an approach similar to the second code snippet is the only way to go?
javascript
firebase firebase-realtime-database asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
I have the following code to retrieve data with timestamps within the given dates and hour ranges:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
return snapshot.ref.orderByKey().startAt(`${hourFrom}`).endAt(`${hourTo}`).once('value').then( (s) => {
console.log(s.val());
return res.status(200).send(s.val());
});
})
});
The database in question looks like follows:
That is, for easy retrieval, I first bucket the items by date, then within the date -- by hour. So, 12 in the above image is 12:00PM.
Now, Firebase does not allow chaining two orderByKey()s, that is why I am trying to query first by date, and then, given a snapshot, trying to iterate over the children using snapshot.forEach(child), like so:
app.get('/mymeals/filtered', async(req,res) => {
let dayFrom= req.query.dayFrom;
let dayTo= req.query.dayTo;
let hourFrom= req.query.hourFrom;
let hourTo= req.query.hourTo;
console.log(`${dayFrom}-${dayTo} ${hourFrom} ${hourTo}`);
let userId= req.user.uid;
return await dbroot.ref(`duplicates/${userId}`)
.orderByKey().startAt(`${dayFrom}`).endAt(`${dayTo}`).once('value').then( (snapshot) => {
console.log(snapshot.val());
acc= ;
snapshot.forEach( (day) => {
day.forEach((hour) => {
console.log("This: " + hour.key);
if (hourFrom <= hour.key && hour.key <= hourTo)
hour.forEach((meal) => {
acc.push(meal.val());
});
});
});
return res.status(200).send(acc);
})
});
My question is, it is still possible to somehow chain the queries along the two axes, or an approach similar to the second code snippet is the only way to go?
javascript
firebase firebase-realtime-database javascript
firebase firebase-realtime-database asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
edited Nov 19 '18 at 18:04
asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
asked Nov 19 '18 at 17:21
Ilonpilaaja
317214
317214
There are two possible meanings here. Do you want meals fromdayFromathourFromuntildayToathourTo? Or do you want meals on for each day fromdayFromuntildayTo, betweenhourFromandhourTo?
– Frank van Puffelen
Nov 19 '18 at 17:56
@FrankvanPuffelen: The second code snippet gets the job done, and indeed it is the second meaning -- the so-called "orthogonal range reporting", in CS parlance.
– Ilonpilaaja
Nov 19 '18 at 18:01
1
That looks like it's the second option from my first comment. There is no way to query two properties in a single query, and from a quick scan it seems like you also can't combine these with a single synthetic property. It looks like you'll need a query for each day at least, unless there are limits that you didn't share (e.g. the time ranges are a fixed, limited number). Also see stackoverflow.com/questions/26700924/…
– Frank van Puffelen
Nov 19 '18 at 18:04
Now I see I indeed used the approach "filter first at server, and the rest at client" approach in my Android code, first binding to a query and additionally filtering inonChildAddedmethod. As for this question, I am using the second snippet, then.
– Ilonpilaaja
Nov 19 '18 at 18:08
add a comment |
There are two possible meanings here. Do you want meals fromdayFromathourFromuntildayToathourTo? Or do you want meals on for each day fromdayFromuntildayTo, betweenhourFromandhourTo?
– Frank van Puffelen
Nov 19 '18 at 17:56
@FrankvanPuffelen: The second code snippet gets the job done, and indeed it is the second meaning -- the so-called "orthogonal range reporting", in CS parlance.
– Ilonpilaaja
Nov 19 '18 at 18:01
1
That looks like it's the second option from my first comment. There is no way to query two properties in a single query, and from a quick scan it seems like you also can't combine these with a single synthetic property. It looks like you'll need a query for each day at least, unless there are limits that you didn't share (e.g. the time ranges are a fixed, limited number). Also see stackoverflow.com/questions/26700924/…
– Frank van Puffelen
Nov 19 '18 at 18:04
Now I see I indeed used the approach "filter first at server, and the rest at client" approach in my Android code, first binding to a query and additionally filtering inonChildAddedmethod. As for this question, I am using the second snippet, then.
– Ilonpilaaja
Nov 19 '18 at 18:08
There are two possible meanings here. Do you want meals from
dayFrom at hourFrom until dayTo at hourTo? Or do you want meals on for each day from dayFrom until dayTo, between hourFrom and hourTo?– Frank van Puffelen
Nov 19 '18 at 17:56
There are two possible meanings here. Do you want meals from
dayFrom at hourFrom until dayTo at hourTo? Or do you want meals on for each day from dayFrom until dayTo, between hourFrom and hourTo?– Frank van Puffelen
Nov 19 '18 at 17:56
@FrankvanPuffelen: The second code snippet gets the job done, and indeed it is the second meaning -- the so-called "orthogonal range reporting", in CS parlance.
– Ilonpilaaja
Nov 19 '18 at 18:01
@FrankvanPuffelen: The second code snippet gets the job done, and indeed it is the second meaning -- the so-called "orthogonal range reporting", in CS parlance.
– Ilonpilaaja
Nov 19 '18 at 18:01
1
1
That looks like it's the second option from my first comment. There is no way to query two properties in a single query, and from a quick scan it seems like you also can't combine these with a single synthetic property. It looks like you'll need a query for each day at least, unless there are limits that you didn't share (e.g. the time ranges are a fixed, limited number). Also see stackoverflow.com/questions/26700924/…
– Frank van Puffelen
Nov 19 '18 at 18:04
That looks like it's the second option from my first comment. There is no way to query two properties in a single query, and from a quick scan it seems like you also can't combine these with a single synthetic property. It looks like you'll need a query for each day at least, unless there are limits that you didn't share (e.g. the time ranges are a fixed, limited number). Also see stackoverflow.com/questions/26700924/…
– Frank van Puffelen
Nov 19 '18 at 18:04
Now I see I indeed used the approach "filter first at server, and the rest at client" approach in my Android code, first binding to a query and additionally filtering in
onChildAdded method. As for this question, I am using the second snippet, then.– Ilonpilaaja
Nov 19 '18 at 18:08
Now I see I indeed used the approach "filter first at server, and the rest at client" approach in my Android code, first binding to a query and additionally filtering in
onChildAdded method. As for this question, I am using the second snippet, then.– Ilonpilaaja
Nov 19 '18 at 18:08
add a comment |
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There are two possible meanings here. Do you want meals from
dayFromathourFromuntildayToathourTo? Or do you want meals on for each day fromdayFromuntildayTo, betweenhourFromandhourTo?– Frank van Puffelen
Nov 19 '18 at 17:56
@FrankvanPuffelen: The second code snippet gets the job done, and indeed it is the second meaning -- the so-called "orthogonal range reporting", in CS parlance.
– Ilonpilaaja
Nov 19 '18 at 18:01
1
That looks like it's the second option from my first comment. There is no way to query two properties in a single query, and from a quick scan it seems like you also can't combine these with a single synthetic property. It looks like you'll need a query for each day at least, unless there are limits that you didn't share (e.g. the time ranges are a fixed, limited number). Also see stackoverflow.com/questions/26700924/…
– Frank van Puffelen
Nov 19 '18 at 18:04
Now I see I indeed used the approach "filter first at server, and the rest at client" approach in my Android code, first binding to a query and additionally filtering in
onChildAddedmethod. As for this question, I am using the second snippet, then.– Ilonpilaaja
Nov 19 '18 at 18:08