[Overview][Constants][Types][Classes][Procedures and functions][Index] Reference for unit 'db' (#fcl)

TBCDField

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

Field class for Binary Coded Decimal (BCD) values

Declaration

Source position: db.pas line 757

type TBCDField = class(TNumericField)

  class procedure CheckTypeSize(); override;

protected

  function GetAsCurrency; override;

  function GetAsFloat; override;

  function GetAsLongint; override;

  function GetAsString; override;

  function GetValue();

  function GetAsVariant; override;

  function GetDataSize; override;

  function GetDefaultWidth; override;

  procedure GetText(); override;

  procedure SetAsFloat(); override;

  procedure SetAsLongint(); override;

  procedure SetAsString(); override;

  procedure SetAsCurrency(); override;

  procedure SetVarValue(); override;

public

  constructor Create(); override;

  

Create a new instance of a TBCDField class.

  function CheckRange();

  

Check whether a values falls within the allowed range

  property Value: Currency; [rw]

  

Value of the field contents as a Currency type

published

  property Precision: LongInt; [rw]

  

Precision of the BCD field

  property Currency: Boolean; [rw]

  

Does the field represent a currency amount

  property MaxValue: Currency; [rw]

  

Maximum value for the field

  property MinValue: Currency; [rw]

  

Minimum value for the field

  property Size;

  

Number of decimals after the decimal separator

end;

Inheritance

TBCDField

  

Field class for Binary Coded Decimal (BCD) values

|

TNumericField

  

Base class for all numerical data field classe

|

TField

  

Provide access to the contents of a single field in a record

|

TComponent,IUnknown,IInterfaceComponentReference

|

TPersistent

|

TObject

Description

TBCDField is the class used when a dataset must manage data of Binary Coded Decimal type. (TField.DataType equals ftBCD). It initializes some of the properties of the TField class, and overrides some of its methods to be able to work with BCD fields.

TBCDField assumes that the field's contents can be stored in a currency type, i.e. the maximum number of decimals after the decimal separator that can be stored in a TBCDField is 4. Fields that need to store a larger amount of decimals should be represented by a TFMTBCDField instance.

It should never be necessary to create an instance of TBCDField manually, a field of this class will be instantiated automatically for each BCD field when a dataset is opened.

See also

TDataset

  

Base class for records-based data-access

TField

  

Provide access to the contents of a single field in a record

TFMTBCDField

The latest version of this document can be found at lazarus-ccr.sourceforge.net.