如何在Firestore中查询集合并将文档聚合为"每天"、"每周"

Question

我的目标是将文档聚合为per day、per week。

存储在Firestore中的文档模板。

document = {
iat: new Date() // Wed Aug 26 2020 HH:MM:SS GMT+... (... Time),
bill: PropTypes.number,
}

预期输出为

data = {
labels: [
08/26/2020,
08/27/2020,
...
],
datasets: [
...
data: [
bill1 + bill2,
bill3 + bill4 + bill5,
bill6,
bill7 + bill8
],
],
}

我尝试过的。输出按文档进行。

firebase
.firestore()
.collection("tickets")
.orderBy("exp")
.get()
.then((snapshot) => {
if (!snapshot.empty) {
setData({
labels: snapshot.docs.map((doc) => {
const data = doc.data();
const exp = data.exp ? new Date(data.exp.seconds * 1000 + data.exp.milliseconds).toString().split(" ").slice(1, 5).join(" ") : null;
return exp;
}),
datasets: [
{
data: snapshot.docs.map((doc) => {
const data = doc.data();
const bill = data.bill ? data.bill : null;
return bill;
}),
},
],
});

tl：dr

我看到的问题是，将iat密钥合并为每天或每小时更容易。而基于CCD_ 5密钥的合并来合并CCD_ 4密钥是困难的。

我现在能想到的是用嵌套逻辑来解决它，我想这会很神秘，如果你有更简单的解决方案，请注意。

我会在找到解决方案后一小时内回来。

谢谢，非常感谢。

Answer 1

这是我的解决方案，一个神秘的解决方案。

// explaining how dataReduced works.
// acc / accumulator intially does not hold value.
// Therefore, on the first iteration acc[key] = acc[key] returns undefined so we fill it with a value { bill: 0, ...cur }.
// accumulator value is remembered across iteration.
// For comparison, in for loop statement, accumulator is similar to `let i = 0; for (i = 0; condition, execution);`
console.log(
dataDateEqualized.reduce((acc, { bill, ...cur }) => {
console.log("acc ", acc, " bill ", bill, " cur ", cur);
const key = Object.entries(cur).join();
console.log("acc ", acc, " key ", key, " before ", acc[key]);
acc[key] = acc[key] || { bill: 0, ...cur };
console.log("acc ", acc, " after ", acc[key], " bill ", bill);
return (acc[key].bill += bill); // this is intentional
}, {})
);

firebase
.firestore()
.collection("tickets")
.orderBy("exp")
.get()
.then((snapshot) => {
if (!snapshot.empty) {
const data = snapshot.docs.map((doc) => {
return doc.data();
});
// console.log(data);
const dataDateEqualized = data.map((data) => {
const date = new Date(
new Date(data.exp.seconds * 1000).setHours(0, 0, 0, 0)
);
const bill = data.bill;
return { "exp": date, bill };
});
// console.log(dataDateEqualized);
const dataReduced = Object.values(
dataDateEqualized.reduce((acc, { bill, ...r }) => {
const key = Object.entries(r).join("-");
acc[key] = acc[key] || { ...r, bill: 0 };
return (acc[key].bill += bill, acc);
}, {})
);
// console.log(dataReduced);
// console.log(dataReduced.map(data => data.exp.toString().split(" ").slice(1, 4).join(" ")))
setData({
labels: dataReduced.map(data => data.exp.toString().split(" ").slice(1, 4).join(" ")),
datasets: [
{
label: "Revenue Report",
fill: false,
lineTension: 0.1,
backgroundColor: "rgba(75,192,192,0.4)",
borderColor: "rgba(75,192,192,1)",
borderCapStyle: "butt",
borderDash: [],
borderDashOffset: 0.0,
borderJoinStyle: "miter",
pointBorderColor: "rgba(75,192,192,1)",
pointBackgroundColor: "#fff",
pointBorderWidth: 1,
pointHoverRadius: 5,
pointHoverBackgroundColor: "rgba(75,192,192,1)",
pointHoverBorderColor: "rgba(220,220,220,1)",
pointHoverBorderWidth: 2,
pointRadius: 1,
pointHitRadius: 10,
data: dataReduced.map(data => data.bill),
}
]
})
} else if (snapshot.empty) setData();
})
.catch((error) => setError(error.message));