javascript - 使用 Modular SDK v9 的 Firestore 条件 where 子句

Question

where()如何使用 Firebase Modular SDK (v9)执行带有条件子句的查询？

名称空间版本 (v8) 中的示例查询：

const status = "live"
const publishedAfter = 1630607348811

let q = firebase.firestore().collection("articles")

// filters selected by users
if (status) q = q.where("status", "==", "live")
if (publishedAfter) q = q.where("publishedAt", ">", publishedAfter)

const qSnapshot = await q.get()

标签： javascriptfirebasegoogle-cloud-firestore

Answer 1

QueryConstraint选项 1：使用以前的作为基础有条件地添加

let q = query(collection(firestore, "articles"))

// filters selected by users
if (status) q = query(q, where("status", "==", "live"))
if (publishedAfter) q = query(q, where("publishedAt", ">", publishedAfter))

const qSnapshot = await getDocs(q);

选项 2：有条件地添加QueryConstraints到数组

const constraints = []

// filters selected by users
if (status) constraints.push(where("status", "==", "live"))
if (publishedAfter) constraints.push(where("publishedAt", ">", publishedAfter))

const q = query(collection(firestore, "articles"), ...constraints)

const qSnapshot = await getDocs(q);