[英]Firestore query documents startsWith a string
是否可以查詢 firestore 集合以獲取以特定字符串開頭的所有文檔?
我已經閱讀了文檔,但沒有找到任何合適的查詢。
與吉爾吉爾伯特的回答相同。 只是一個增強和一些示例代碼。 使用String.fromCharCode和String.charCodeAt
var strSearch = "start with text here";
var strlength = strSearch.length;
var strFrontCode = strSearch.slice(0, strlength-1);
var strEndCode = strSearch.slice(strlength-1, strSearch.length);
var startcode = strSearch;
var endcode= strFrontCode + String.fromCharCode(strEndCode.charCodeAt(0) + 1);
然后過濾代碼如下。
db.collection(c)
.where('foo', '>=', startcode)
.where('foo', '<', endcode);
適用於任何語言和任何 Unicode。
警告:firestore 中的所有搜索條件都區分大小寫。
const text = 'start with text here';
const end = text.replace(/.$/, c => String.fromCharCode(c.charCodeAt(0) + 1));
query
.where('stringField', '>=', text)
.where('stringField', '<', end);
async function search(startsWith = '') {
let query = firestore.collection(COLLECTION.CLIENTS);
if (startsWith) {
const end = startsWith.replace(
/.$/, c => String.fromCharCode(c.charCodeAt(0) + 1),
);
query = query
.where('firstName', '>=', startsWith)
.where('firstName', '<', end);
}
const result = await query
.orderBy('firstName')
.get();
return result;
}
final strFrontCode = term.substring(0, term.length - 1);
final strEndCode = term.characters.last;
final limit =
strFrontCode + String.fromCharCode(strEndCode.codeUnitAt(0) + 1);
final snap = await FirebaseFirestore.instance
.collection('someCollection')
.where('someField', isGreaterThanOrEqualTo: term)
.where('someField', isLessThan: limit)
.get();
我找到了這個,它非常適合startsWith
const q = query(
collection(firebaseApp.db, 'capturedPhotos'),
where('name', '>=', name),
where('name', '<=', name + '\uf8ff')
)
以上都是正確的! 只是想給出一個更新的答案!
var end = s[s.length-1]
val newEnding = ++end
var newString = s
newString.dropLast(1)
newString += newEnding
query
.whereGreaterThanOrEqualTo(key, s)
.whereLessThan(key, newString)
.get()
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