Understanding Reads

Why eeCLOUD Does Not Provide a Traditional ReadById

In many systems, ReadById is the primary access pattern. eeCLOUD focuses on a different model: time-ordered data and memory snapshots.

For most real-world use cases (sessions, device state, configurations, user timeline, latest event), the question is not "give me record X" but rather "give me the most relevant record now".

Single-Record Reads and the Order Parameter

Several read methods are logically single-record reads. When multiple matches exist, the Order parameter decides which record is returned.

Order	Single-record result
DESC (default)	Most recent record (last inserted)
ASC	Oldest record (first inserted)

// Latest record
await app.ReadData("myApp", "sessions");

// First record
await app.ReadData("myApp", "sessions", Order.ASC);

The Deterministic Handle: Address

The most deterministic way to read a specific record is using its address (MemoryArea.address). The address is the stable handle used by update and delete operations.

var single = await app.ReadData("myApp", "users", address);

Read Patterns

1) Read latest (or first) record from a Memory

// Latest (default)
await app.ReadData("myApp", "config");

// First
await app.ReadData("myApp", "config", Order.ASC);

2) Read by id

eeCLOUD supports id-based reads, but they are still order-aware when multiple matches exist.

await app.ReadData("myApp", "users", id);
await app.ReadData("myApp", "users", id, Order.DESC, deleted: false);

3) Read by index

await app.ReadIndexData("myApp", "users", index);

4) Read by field and value

await app.ReadData("myApp", "users", "email", "[email protected]");

5) Read by reference

Reference-based reads are the fastest way to retrieve user/tenant/device owned data.

// Latest record for a given reference
await app.ReadRefData("myApp", "orders", userId);

// Read by reference + index
await app.ReadRefData("myApp", "orders", userId, index);

6) Read by combinations

// index + id
await app.ReadData("myApp", "orders", index, id);

// reference + id
await app.ReadRefData("myApp", "orders", userId, id);

// reference + index + id
await app.ReadRefData("myApp", "orders", userId, index, id);

// reference + field/value
await app.ReadData("myApp", "orders", userId, "status", "paid");

Deleted Records

Many reads accept a deleted parameter. When false (default), soft-deleted records are excluded. When true, soft-deleted records are included.

// Include soft-deleted data
await app.ReadData("myApp", "users", id, Order.DESC, deleted: true);

From Reads to Stable Updates

A common pattern is:

// 1) Read latest
var mem = await app.ReadRefData("myApp", "sessions", userId);

// 2) Take the address
var addr = mem.area[0].address;

// 3) Update deterministically
await app.UpdateValue("myApp", "sessions", addr, "active", false);