Wt: Wt::Dbo::dbo_default_traits Class Reference

Wt 4.10.4

Loading...
Searching...
No Matches
Public Types | Static Public Member Functions | List of all members
Wt::Dbo::dbo_default_traits Class Reference
Database Objects (Wt::Dbo)

Default traits for a class mapped with Wt::Dbo. More...

Inheritance diagram for Wt::Dbo::dbo_default_traits:
[legend]

## Public Types
typedef long long | IdType
| Type of the primary key.

## Static Public Member Functions
static IdType | invalidId ()
| Returns the sentinel value for a `null` id.
static const char * | surrogateIdField ()
| Returns the database field name for the surrogate primary key.
static const char * | versionField ()
| Configures the optimistic concurrency version field.

## Detailed Description

Default traits for a class mapped with Wt::Dbo.

This class provides the default traits. It is convenient (and future proof) to inherit these default traits when customizing the traits for one particular class.

## Member Typedef Documentation

## ◆ IdType

long long Wt::Dbo::dbo_default_traits::IdType

Type of the primary key.

The default corresponds to a surrogate key, which is `long long`.

## Member Function Documentation

## ◆ invalidId()

static IdType Wt::Dbo::dbo_default_traits::invalidId | ( |  | ) |
| static

Returns the sentinel value for a `null` id.

The default implementation returns -1.

## ◆ surrogateIdField()

static const char * Wt::Dbo::dbo_default_traits::surrogateIdField | ( |  | ) |
| static

Returns the database field name for the surrogate primary key.

The default surrogate id database field name is `"id"`.

## ◆ versionField()

static const char * Wt::Dbo::dbo_default_traits::versionField | ( |  | ) |
| static

Configures the optimistic concurrency version field.

By default, optimistic concurrency locking is enabled using a `"version"` field.