select

The select builder is used to retrieve data from your DynamoDB tables. It intelligently chooses between GetItem, Query, and Scan based on the filters provided in your where clause.

Usage

import { db } from "./db";
import { users } from "./schema";
import { eq } from "@aurios/mizzle";

const result = await db.select().from(users).where(eq(users.id, "123")).execute();

Methods

select(fields?)

Initializes the select builder. You can optionally pass an object to specify which fields should be returned (Projections).

• Arguments:
  • fields (optional): An object mapping field names to column definitions.
• Returns: SelectBuilder

from(entity)

Specifies the entity you want to select from.

• Arguments:
  • entity: A Mizzle entity definition.
• Returns: SelectBase

where(expression)

Adds a filter to the query. Mizzle will analyze this expression to determine if it can use an index or a direct key lookup.

• Arguments:
  • expression: A Mizzle expression (e.g., eq(), and(), beginsWith()).
• Returns: this

execute()

Executes the query against DynamoDB and returns a promise that resolves to an array of items.

• Returns: Promise<T[]>

Intelligent Routing

Mizzle’s select is powerful because it abstracts DynamoDB’s different read operations:

1. GetItem: Triggered when the where clause provides both the Partition Key and Sort Key for the main table.
2. Query: Triggered when only the Partition Key is provided, or when keys matching a Global Secondary Index (GSI) are provided.
3. Scan: Triggered when no keys can be resolved from the where clause. Note: Scans are expensive and should be used with caution.