| name | cloudbase-document-database-web-sdk |
| description | Use CloudBase document database Web SDK to query, create, update, and delete data. Supports complex queries, pagination, aggregation, realtime, and geolocation queries. |
| version | 2.18.0 |
| alwaysApply | false |
Standalone Install Note
If this environment only installed the current skill, start from the CloudBase main entry and use the published cloudbase/references/... paths for sibling skills.
- CloudBase main entry:
https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/SKILL.md - Current skill raw source:
https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/no-sql-web-sdk/SKILL.md
Keep local references/... paths for files that ship with the current skill directory. When this file points to a sibling skill such as auth-tool or web-development, use the standalone fallback URL shown next to that reference.
CloudBase Document Database Web SDK
Activation Contract
Use this first when
- A browser or Web app must read or write CloudBase document database data through
@cloudbase/js-sdk. - The request mentions
app.database(),db.collection(),.where(),.watch(), pagination, aggregation, or geolocation queries in a Web frontend.
Read before writing code if
- The task is clearly browser-side, but you still need to decide between Web SDK, Mini Program SDK, or backend access.
- The request touches login state, collection permissions, or realtime updates.
Then also read
- Web login and caller identity ->
../auth-web/SKILL.md(standalone fallback:https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/auth-web/SKILL.md) - General Web app structure ->
../web-development/SKILL.md(standalone fallback:https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/web-development/SKILL.md) - Mini Program database code ->
../no-sql-wx-mp-sdk/SKILL.md(standalone fallback:https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/no-sql-wx-mp-sdk/SKILL.md)
Do NOT use for
- Mini Program code using
wx.cloud.database(). - Server-side or cloud-function database access.
- SQL / MySQL database operations.
- Pure resource-permission administration with no browser SDK code.
SDK Code vs MCP Tools
When to write SDK code (use this skill):
- The task explicitly asks to "modify code" or "use SDK"
- The task asks to implement app/frontend logic
- The task mentions specific SDK methods like
db.collection().add(),.get(),.update() - The context shows an existing Web project with SDK initialization (e.g.,
index.jsalready hascloudbase.init())
When to use MCP tools instead:
- The task asks to manage CloudBase resources (create collection, set permissions, etc.)
- The task involves admin/management operations without writing app code
- The task mentions tools like
writeNoSqlDatabaseContent,managePermissions, etc.
Key distinction: If the user says "使用 JS SDK 执行 XX 操作" (use JS SDK to perform XX operation) or "修改代码" (modify code), write SDK code in the project files. Do not use MCP database write tools for app-level data operations.
Common mistakes / gotchas
- Querying before the user is signed in when the collection rules require identity.
- Using
wx.cloud.database()or Node SDK patterns in browser code. - Initializing CloudBase lazily with dynamic imports instead of a shared synchronous app instance.
- Treating security rules as result filters rather than request validators.
- Expecting a
CUSTOMsecurity rule to take effect immediately after you callmanagePermissions(updateResourcePermission). The backend caches rule evaluators for 2–5 minutes; first writes after a rule change may silently fail or be rejected withDATABASE_PERMISSION_DENIEDeven when the expression is correct. Either (a) wait a few minutes and retry the same write before assuming the rule is wrong, or (b) verify the rule is live by readingresult.code/result.messageon every write and by doing aget()round-trip on the just-written_id; do not treat a resolved promise as success. Seesecurity-rules.md→ "Propagation And Verification" for the full pattern. - Misreading the return shape of
db.collection(...).add(...). In the CloudBase Web SDK, the created document ID is exposed at top-levelresult._id, notresult.id,result.data.id, orresult.insertedId. - For CMS-style collections that need app-level admin users to edit/delete all records while editors can only edit/delete their own records, do not oversimplify the rule to
READONLY. A validated pattern is aCUSTOMrule that reads role fromuser_rolesbyauth.uidand combines it withdoc.authorId == auth.uid, while frontend writes can stay on.doc(id).update()/.doc(id).remove(). - Forgetting pagination or indexes for larger collections.
Minimal checklist
- Confirm this is browser-side document database work.
- Initialize CloudBase once and reuse the same
app/dbinstance. - Verify auth expectations before CRUD.
- Read the right companion reference file for the specific operation.
Overview
This skill covers browser-side document database usage via @cloudbase/js-sdk.
Use it for:
- CRUD in a Web app
- complex queries and pagination
- aggregation
- realtime listeners with
watch() - geolocation queries
Canonical initialization
import cloudbase from "@cloudbase/js-sdk";
const app = cloudbase.init({
env: "your-env-id"
});
const db = app.database();
const _ = db.command;
Important rules:
- Sign in before querying if the collection rules require identity.
- Keep a single shared app/database instance.
- Do not hide initialization inside ad-hoc async loaders unless the framework truly requires it.
Quick routing
- CRUD ->
./crud-operations.md - Complex queries ->
./complex-queries.md - Pagination ->
./pagination.md - Aggregation ->
./aggregation.md - Realtime listeners ->
./realtime.md - Geolocation ->
./geolocation.md - Security rules ->
./security-rules.md
Working rules for a coding agent
Start from the auth model
- If the page relies on logged-in user identity, read the Web auth skill before writing database code.
Keep browser code browser-native
- Use
app.database()and collection references. - Do not mix in MCP management flows or SQL mental models.
- Use
Respect security rules
- Collection rules can reject requests before data is read.
- If the requirement is simple owner-only write access,
READONLYcan be enough. - If the requirement is “app-level admin can edit/delete all, editor only own”, use a
CUSTOMrule. A validated CMS pattern isget('database.user_roles.' + auth.uid).role == 'admin' || doc.authorId == auth.uid. - For that CMS pattern, frontend writes can stay on
.doc(id).update()/.doc(id).remove(). - Reuse whichever role collection already exists and can be addressed by
_id == auth.uid. In this CMS pattern,user_roleskeyed by uid is acceptable. - If the task fails with permission issues, inspect the rule model rather than assuming the query syntax is wrong.
Return user-friendly errors
- Database errors must become readable UI or application errors, not silent failures.
- For writes, do not treat a resolved promise as success by default. Check write result fields such as
updated/deletedor surfacedcode/message.
Persist IDs from create operations correctly
- For Web SDK
.add(...), the newly created document ID isresult._id. - Do not look for the ID under
result.id,result.data, or other driver-specific fields.
- For Web SDK
Quick examples
Simple query
const result = await db.collection("todos")
.where({ completed: false })
.get();
Create and capture document ID
const result = await db.collection("posts").add({
title: "New article",
content: "...",
createdAt: new Date()
});
const articleId = result._id;
Ordered pagination
const result = await db.collection("posts")
.orderBy("createdAt", "desc")
.skip(20)
.limit(10)
.get();
Field selection
const result = await db.collection("users")
.field({ name: true, email: true, _id: false })
.get();
Best practices
- Define collection-level types or model wrappers in the app code.
- Use meaningful collection naming conventions.
- Select only required fields.
- Add indexes for frequent filters or sort keys.
- Pair frontend CRUD with explicit permission design.
- Use pagination instead of unbounded reads.
Error handling
try {
const result = await db.collection("todos").get();
console.log(result.data);
} catch (error) {
console.error("Database error:", error);
}
When the SDK returns an operation result, check error indicators and translate them into readable application behavior.