bkend-data

name	bkend-data
classification	C
description	bkend.ai database expert skill. Covers table creation, CRUD operations, 7 column types, constraints, filtering (AND/OR, 10 operators), sorting, pagination, relations, joins, indexing, and schema management via MCP and REST API. Triggers: table, column, CRUD, schema, index, filter, query, data model, 테이블, 컬럼, 스키마, 인덱스, 필터, 쿼리, 데이터 모델, テーブル, カラム, スキーマ, インデックス, フィルター, 数据表, 列, 模式, 索引, 过滤, 查询, tabla, columna, esquema, indice, filtro, consulta, tableau, colonne, schema, index, filtre, requete, Tabelle, Spalte, Schema, Index, Filter, Abfrage, tabella, colonna, schema, indice, filtro, query Do NOT use for: authentication (use bkend-auth), file storage (use bkend-storage), MCP setup (use bkend-mcp), security policies (use bkend-security)
user-invocable	true
argument-hint
allowed-tools	["read_file","write_file","replace","glob","grep_search","run_shell_command","web_fetch"]
imports	[]
agents	{"backend":"bkend-expert"}
context	session
memory	project
pdca-phase	all

bkend-data: Database Expert Skill

Complete database management for bkend.ai projects using MongoDB Atlas

1. Overview

bkend.ai provides a fully managed database layer built on MongoDB Atlas. Each project operates in complete data isolation, with built-in schema validation and Row-Level Security (RLS) policies.

Key characteristics:

• MongoDB Atlas backend with project-level isolation
• Schema validation enforced at the database level
• Row-Level Security (RLS) for fine-grained access control
• Automatic system fields on every record
• REST API and MCP tools for full database management

2. Data Model

2.1 Column Types (7 Types)

bkend.ai supports exactly 7 column types. There is no generic "number" type.

Type	Description	Example
string	Text data, UTF-8 encoded	"Hello World"
int	Integer numbers (no decimals)	42
double	Floating-point numbers	3.14
bool	Boolean true/false	true
date	ISO 8601 date-time string	"2025-01-15T09:30:00Z"
object	Nested JSON object	{ "city": "Seoul", "zip": "06000" }
array	Array of values	["tag1", "tag2", "tag3"]

IMPORTANT: Do NOT use "number" as a column type. Use int for integers or double for decimals.

2.2 System Fields (Auto-Generated)

Every record automatically includes these system fields. Do NOT define them manually.

Field	Type	Description
id	string	Unique record identifier (auto-generated)
createdBy	string	User ID of the creator (auto-set)
createdAt	date	Creation timestamp (auto-set)
updatedAt	date	Last update timestamp (auto-set)

2.3 Constraints

Apply constraints to columns for data integrity:

Constraint	Description	Example
required	Field must have a value	required: true
unique	Value must be unique across all records	unique: true
default	Default value when not provided	default: "active"
min	Minimum value (int/double) or length (string)	min: 0
max	Maximum value (int/double) or length (string)	max: 100
enum	Restrict to a set of allowed values	enum: ["active", "inactive", "pending"]

2.4 Default Indexes

Every table is created with these indexes by default:

Index Name	Fields	Purpose
_id_	id	Primary key lookup
idx_createdAt_desc	createdAt descending	Sort by creation date
idx_updatedAt_desc	updatedAt descending	Sort by update date
idx_createdBy	createdBy	Filter by owner

3. CRUD REST API

All data endpoints require authentication via the Authorization: Bearer <token> header and the x-project-id header.

3.1 Create Record

Single record:

POST /v1/data/:tableName
Content-Type: application/json

{
  "name": "John Doe",
  "email": "[e-mail]",
  "age": 30,
  "role": "user"
}

Batch create (multiple records):

POST /v1/data/:tableName
Content-Type: application/json

{
  "records": [
    { "name": "Alice", "email": "[e-mail]", "age": 25 },
    { "name": "Bob", "email": "[e-mail]", "age": 28 }
  ]
}

Response:

{
  "success": true,
  "data": {
    "id": "rec_abc123",
    "name": "John Doe",
    "email": "[e-mail]",
    "age": 30,
    "role": "user",
    "createdBy": "usr_xyz",
    "createdAt": "2025-01-15T09:30:00Z",
    "updatedAt": "2025-01-15T09:30:00Z"
  }
}

3.2 Read One Record

GET /v1/data/:tableName/:id

Response:

{
  "success": true,
  "data": {
    "id": "rec_abc123",
    "name": "John Doe",
    "email": "[e-mail]",
    "age": 30,
    "role": "user",
    "createdBy": "usr_xyz",
    "createdAt": "2025-01-15T09:30:00Z",
    "updatedAt": "2025-01-15T09:30:00Z"
  }
}

3.3 List Records

GET /v1/data/:tableName?filter={...}&sort={...}&limit=20&cursor=last_id&search=keyword&searchType=partial

Query Parameters:

Parameter	Type	Description
filter	JSON	Filter conditions (see Section 4)
sort	JSON	Sort order (see Section 5)
limit	int	Number of records to return (max 100, default 20)
cursor	string	Cursor for pagination (last record ID)
search	string	Full-text or partial search keyword
searchType	string	Search mode: "exact" or "partial"

Response:

{
  "success": true,
  "data": [
    { "id": "rec_abc123", "name": "John Doe", "age": 30 },
    { "id": "rec_def456", "name": "Jane Smith", "age": 25 }
  ],
  "meta": {
    "total": 150,
    "limit": 20,
    "nextCursor": "rec_def456"
  }
}

3.4 Update Record

PUT /v1/data/:tableName/:id
Content-Type: application/json

{
  "name": "John Updated",
  "age": 31
}

Response:

{
  "success": true,
  "data": {
    "id": "rec_abc123",
    "name": "John Updated",
    "age": 31,
    "updatedAt": "2025-01-16T10:00:00Z"
  }
}

3.5 Delete Record

DELETE /v1/data/:tableName/:id

Response:

{
  "success": true,
  "data": {
    "id": "rec_abc123",
    "deleted": true
  }
}

3.6 Table Specification

Retrieve the full schema definition for a table:

GET /v1/data/:tableName/spec

Response:

{
  "success": true,
  "data": {
    "tableName": "users",
    "fields": [
      { "name": "name", "type": "string", "required": true },
      { "name": "email", "type": "string", "required": true, "unique": true },
      { "name": "age", "type": "int", "min": 0, "max": 150 },
      { "name": "role", "type": "string", "enum": ["user", "admin"], "default": "user" }
    ],
    "indexes": [
      { "name": "_id_", "fields": ["id"] },
      { "name": "idx_createdAt_desc", "fields": [{ "createdAt": -1 }] }
    ]
  }
}

4. Filtering

4.1 AND Filtering (Default)

Multiple conditions in the same filter object are combined with AND logic:

{
  "filter": {
    "status": { "$eq": "active" },
    "age": { "$gte": 18 }
  }
}

This returns records where status equals "active" AND age is greater than or equal to 18.

4.2 OR Filtering

Use the $or operator to combine conditions with OR logic:

{
  "filter": {
    "$or": [
      { "status": "active" },
      { "role": "admin" }
    ]
  }
}

This returns records where status equals "active" OR role equals "admin".

4.3 Filter Operators (10 Operators)

Operator	Description	Example
$eq	Equal to	{ "status": { "$eq": "active" } }
$ne	Not equal to	{ "status": { "$ne": "deleted" } }
$gt	Greater than	{ "age": { "$gt": 18 } }
$gte	Greater than or equal	{ "age": { "$gte": 18 } }
$lt	Less than	{ "price": { "$lt": 100 } }
$lte	Less than or equal	{ "price": { "$lte": 99.99 } }
$in	In array of values	{ "role": { "$in": ["admin", "editor"] } }
$nin	Not in array	{ "status": { "$nin": ["deleted", "banned"] } }
$regex	Regular expression match	{ "name": { "$regex": "^John" } }
$exists	Field exists or not	{ "profileImage": { "$exists": true } }

4.4 Search

Use query parameters for text search: