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Fetch Data

Initialize the SDK​

import cloudbase from "@cloudbase/js-sdk";

const app = cloudbase.init({
  env: env: "your-env-id", // Replace with your environment id
});

const db = app.rdb();

// or specify the instance and database
// const db = app.rdb({
//   instance: "<instance>",
//   database: "<database>"
// });

Basic Queries​

Query table data through the select() method, supporting features such as conditional filtering and join queries.

db.from(tableName).select(columns, options);
  • tableName: table name
  • columns: columns to search, separated by commas
  • options: query options configuration

Parameter Description​

ParameterTypeRequiredDescription
columnsstringNoColumns to search, separated by commas. You can rename columns in the output using customName:aliasName
optionsobjectNoQuery options configuration

options Parameter Description​

ParameterTypeRequiredDescription
countstringNoCounting algorithm, optional values: "exact" - underlying execution of COUNT(*)
headbooleanNoWhen set to true, no data is returned. This is only useful for counting

Code Example​

Querying All Data​

// Query all data from the articles table
const { data, error } = await db.from("articles").select();

console.log("Query result:", data);

Querying Specified Columns​

// Query only the title and creation time of the articles
const { data, error } = await db.from("articles").select("title, created_at");

console.log("Query result:", data);

Response​

{
    data: [
        {
            id: 1,
            title: title: "Article Title",
            created_at: "2023-01-01T00:00:00Z"
        },
        // ... other records
    ],
    error: null
}

Join Table Query​

Join queries enable simultaneous data retrieval from multiple tables, supporting one-to-one, one-to-many, and other relationship types.

Basic Join Query​

// Query article data and retrieve associated category information
const { data, error } = await db.from("articles").select(`
    title,
    categories (
      name
    )
  `);

console.log("Query result:", data);

Multiple Join Query​

// Query articles and obtain creator and modifier information
const { data, error } = await db.from("articles").select(`
    title,
    created_by:users!articles_created_by_fkey(name),
    updated_by:users!articles_updated_by_fkey(name)
  `);

console.log("Query result:", data);

💡 Note: When the same table is associated multiple times through different foreign keys, use the foreign key constraint names to distinguish between the different associations.

Nested Join Query​

// Query categories and all articles under them, along with the author information of the articles.
const { data, error } = await db.from("categories").select(`
    name,
    articles (
      title,
      users (
        name
      )
    )
  `);

console.log("Query result:", data);

Advanced Query​

Conditional Filtering Query​

// Query all articles under a specific category
const { data, error } = await db
  .from("articles")
  .select("title, categories(*)")
  .eq("categories.name", "Technical Articles");

console.log("Query result:", data);

Count Query​

// Obtain each category and its article count
const { data, error } = await db
  .from("categories")
  .select(`*, articles(count)`);

console.log("Query result:", data);

Obtain Only the Total Count​

// Obtain only the total article count without returning specific data
const { count, error } = await db
  .from("articles")
  .select("*", { count: "exact", head: true });

console.log("Total:", count);

Inner Join Query​

// Obtain only articles with categories, using inner join to ensure categories exist
const { data, error } = await db
  .from("articles")
  .select("title, categories!inner(name)")
  .eq("categories.name", "Tutorial")
  .limit(10);

console.log("Query result:", data);

💡 Note: !inner represents an inner join, returning only data with matching records in the associated table.

  • Filter - Learn how to use filter conditions
  • Modifier - Learn how to use query modifiers