# Poco

# namespace ActiveRecord

## Overview

Classes: ActiveRecord, ActiveRecordBase, Context, DefaultStatementPlaceholderProvider, IDTraits, KeylessActiveRecord, PostgresStatementPlaceholderProvider, Query, StatementPlaceholderProvider

## Classes

### class ActiveRecord

The base class for all database objects that implement the ActiveRecord pattern, with a single key column.

### class ActiveRecordBase

The base class for the ActiveRecord class template.

### class Context

Context information for ActiveRecord objects.

### class DefaultStatementPlaceholderProvider

### class IDTraits

Traits for ID/index types.

### class KeylessActiveRecord

The base class for all database objects that implement the ActiveRecord pattern, without a key column.

### class PostgresStatementPlaceholderProvider

### class Query

A Query is used to retrieve ActiveRecord objects from a table.

### class StatementPlaceholderProvider

## Variables

### >::INVALID_ID

template < typename IDType > const IDType ActiveRecord < IDType >::INVALID_ID = IDTraits < IDType >::INVALID_ID;