foreach语句中的Firestore复合查询 [英] Firestore Compound Queries inside foreach statement

问题描述

如果可能的话，我想要一些帮助，我想在2个foreach语句中进行Firestore复合查询，因为我需要获取与循环数组中的内容相匹配的所有相关数据。

I would like some help if possible, I want to do a Firestore compound query inside 2 foreach statements as I need to get all relevant data back that matches the contents in the arrays being looped through.

arenas.forEach((arenasElement: any) => {
    sports.forEach((sportsElement: any) => {
        firebaseAdmin.firestore().collection('leagues')
            .where('arenaUid', '==', arenasElement)
            .where('sportUid', '==', sportsElement)
            .get()
            .then((querySnapshot: any) => {
                querySnapshot.docs.map((element: any) => {
                    leaguesArray.push(element.data())
                })
            })
            .catch((error) => {
                console.log(error)
                res.send(error)
            })
    })
})

I需要所有相关结果存储在数组中，因为它们都是对象&当所有查询都完成执行时，我想返回该数组，因为我需要所有数据。

I need all the relevant results to be stored in the array as all of them are objects & I want to return that array when all of the queries are finished executing as I need all the data.

我已经尝试过查看promises&包装它，但我在这件事上没有成功。

I've tried looking at promises & wrapping it but I had no success in the matter.

任何帮助都将很乐意赞赏！

Any help would be gladly appreciated!

编辑：以上回答如下，但我正在努力解决另一个问题

The above got answered with below but I am struggling with another function I have

export const getSports = firebaseFunctions.https.onRequest((req: any, res: any) => {
cors(req, res, () => {
    let sportsUidArray: any = []
    let sportsArray: any = []
    let arenas: any = []
    let promises: any = []

    arenas = req.body.arenas

    arenas.forEach((arenasElement: any) => {
        promises.push(
            firebaseAdmin.firestore()
                .collection('leagues')
                .where('arenaUid', '==', arenasElement)
                .orderBy('title')
                .get()
        )
    })

    Promise.all(
        promises
    ).then((querySnapshots: any) => {
        querySnapshots.forEach((snapshotElement: any) => {
            snapshotElement.docs.map((element: any) => {
                sportsUidArray.push(element.data().sportUid)
            })
        })

        sportsUidArray = Array.from(new Set(sportsUidArray))

        promises = []

        sportsUidArray.forEach((sportIdElement: any) => {
            promises.push(
                firebaseAdmin.firestore()
                    .collection('sports')
                    .doc(sportIdElement)
                    .get()
            )
        })

        Promise.all(
            promises
        ).then((querySnapshots2: any) => {
            querySnapshots2.forEach((snapshotElement: any) => {
                /* Issue with line below */
                snapshotElement.docs.map((sportsElement: any) => {
                    sportsArray.push({ id: sportsElement.id, data: sportsElement.data() })
                })
            })

            res.send(sportsArray)
        }).catch((err: any) => {
            res.send(err)
            console.error(err)
        })
    }).catch((err: any) => {
        res.send(err)
        console.error(err)
    })
})

}）

我从Firebase收到错误：

Error I'm receiving from Firebase:

TypeError: Cannot read property 'map' of undefined

推荐答案

这应该可以解决问题：

var promises = [];
arenas.forEach((arenasElement: any) => {
    sports.forEach((sportsElement: any) => {
        promises.push(firebaseAdmin.firestore().collection('leagues')
            .where('arenaUid', '==', arenasElement)
            .where('sportUid', '==', sportsElement)
            .get());
    })
})
Promise.all(promises).then((snapshots: any) => {
    var leaguesArray = [];
    snapshots.forEach((querySnapshot: any) => {
        querySnapshot.docs.map((element: any) => {
            leaguesArray.push(element.data())
        })
    })
    res.send(JSON.stringify(leaguesArray));
})
.catch((error) => {
    console.log(error)
    res.send(error)
})

你会请注意我的更改非常小：

You'll note that my changes are pretty small:

1. 使用加载数据的代码创建一个promises数组。


2. 输入你的代码 t hen（）到一个然后（）在所有数据加载后触发（使用 Promise.all（））。

1. Create an array of promises with the code that load the data.
2. Put the code of you then() into a single then() that fires after all data has loaded (with Promise.all()).

这篇关于foreach语句中的Firestore复合查询的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！