> ## Documentation Index
> Fetch the complete documentation index at: https://docs.revoengine.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Database API

> Query and mutate RevoEngine databases safely from low-code.

Use the structured query API for most reads and writes. It provides explicit fields, filters, grouping, sorting, pagination, and JSON-path behavior without assembling SQL strings.

## Read rows

```js theme={null}
const response = await api.getDatabaseData('orders', {
  fields: ['orderId', 'customerId', 'amount', 'createdAt'],
  filter: {
    and: [
      { field: 'status', op: 'eq', value: 'CONFIRMED' },
      { field: 'amount', op: 'gte', value: 100, filterType: 'number' },
    ],
  },
  sort: { createdAt: 'DESC' },
  take: 100,
});

return { rows: response.data, next: response.next };
```

Prefer a narrow field projection and bounded `take`. Follow the returned cursor or next-page contract instead of loading an unbounded table.

## Mutate rows

Use the dedicated insert, upsert, update, and delete methods. Bulk update and delete accept the canonical structured filter tree.

```js theme={null}
await api.updateDatabaseDataRequest(
  'orders',
  { filter: { field: 'status', op: 'eq', value: 'NEW' }, take: 1000 },
  { status: 'QUEUED' },
);
```

## Transactions

Use `api.transactionDatabase()` for check-then-write workflows that must commit together.

```js theme={null}
const created = await api.transactionDatabase(async (tx) => {
  const customerId = api.input('customerId');
  const existing = await tx.getDatabaseData(
    'customers',
    { filter: { field: 'customerId', op: 'eq', value: customerId }, take: 1 },
    { lock: 'update' },
  );

  if (existing.results === 0) {
    await tx.insertDatabaseData('customers', [{ customerId, status: 'ACTIVE' }]);
  }
  return existing.results === 0;
});
```

Await transaction calls sequentially. Keep sleeps and remote HTTP/SFTP side effects outside the callback because a transaction reserves a connection and may hold row locks.

## Raw SQL

`api.queryDatabase()` is for parameterized `SELECT` or `WITH` reads when the structured builder cannot express the query. Use the mutation helpers for writes.