Wt  4.9.1
Public Types | Static Public Member Functions | List of all members
Wt::Dbo::dbo_default_traits Class Reference

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

Inheritance diagram for Wt::Dbo::dbo_default_traits:
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Public Types

typedef long long IdType
 Type of the primary key. More...
 

Static Public Member Functions

static IdType invalidId ()
 Returns the sentinel value for a null id. More...
 
static const char * surrogateIdField ()
 Returns the database field name for the surrogate primary key. More...
 
static const char * versionField ()
 Configures the optimistic concurrency version field. More...
 

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

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.