TDABaseField

From RemObjects Software

This is a Data Abstract Architecture entry
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Overview

TDABaseField is the abstract base class for field and parameter definitions in Data Abstract.

It provides the common elements of the following classes:

• TDAField used for field definitions in data tables, both in the schema and data dictionaries as well as in live TDADataTables.
• TDAParam used for parameter definitions in commands and data tables.

File

uDAInterfaces

Declaration

TDABaseField = class(TInterfacedCollectionItem);

Hierarchy

• TInterfacedCollectionItem
  • TDABaseField

Properties

Property	Type	Description
AsBoolean	Boolean	Gets or sets the value of the field as Boolean value.
AsCurrency	Currency	Gets or sets the value of the field as 64-bit fixed point Currency value.
AsDateTime	TDateTime	Gets or sets the value of the field as TDateTime value.
AsFloat	Double	Gets or sets the value of the field as Float/Double value.
AsInteger	Integer	Gets or sets the value of the field as 32-bit integer value.
AsLargeInt	Int64	Gets or sets the value of the field as 64-bit integer value.
AsString	String	Gets or sets the value of the field as 8-bit ANSI string value.
AsVariant	Variant	Gets or sets the value of the field as variant.
AsWideString	WideString	Gets or sets the value of the field as 16-bit Unicode WideString value.
BlobType	TDABlobType	Manages additional Blob options, if the DataType of the field is set to datBlob.
DataType	TDADataType	Specifies the type of data contained within the field, from a collection of supported TDADataTypes. Depending on the data type, the Size and BlobType properties are also used to further define the data type in more detail. For datString and datWideString, Size will define the maximum length of string permitted for the field; for blobs and memos, BlobType provides special options.
Description	String	Provides a human-readable description of the field. This property will not be used by the Data Abstract library, but can be filled with description text for documentation purposes when defining the field or parameter in Schema Modeler.
DictionaryEntry	String	Specifies the data dictionary entry to use for this field. If assigned (and a TDADataDictionary is assigned to the schema), specific properties of the field will automatically be filled from the data dictionary, rather then being stored with the field itself. This allows to easily share field attributes across an entire application, by defining common field settings in the data dictionary and linking all relevant fields to that dictionary entry. The following field properties are affected by this. If you are using Schema Modeler to edit your field definition, you will notice that these fields automatically gray out as you assign the DictionaryEntry: Alignment BlobType BusinessClassID DataType DefaultValue DisplayFormat DisplayLabel DisplayWidth EditFormat EditMask GeneratorName ReadOnly RegExpression Required Size Visible
GeneratorName	String	For fields of type datAutoInc, this property specifies the name of the generator in the back-end database that will be used to generate new primary key values. This applies only to database types that do not natively support AutoInc fields (such as Oracle or Interbase). Please refer to the AutoIncs and Generators help topic for more details.
IsNull	Boolean	Returns whether the field currently contains a value (false) or is Null (true).
Name	String	Defines the name of the field or parameter. This name usually matches the name of the underlying field in the physical database, or it's mapped to a different field using the data tables column mapping.
Size	Integer	Sets the maximum length of string permitted for the field, DataType is set to datString or datWideString.
Value	Variant	Gets or sets the value of the field as variant.

Methods

Method	Description
Clear	Clears the value of the field by setting it to Null.

See Also

• TDAField
• TDAParam
• Lists
  • Class List (Data Abstract for Delphi)
  • Interface List (Data Abstract for Delphi)
  • Enum List (Data Abstract for Delphi)
  • Data Types (Data Abstract)
  • File Types (Data Abstract)

Product: RemObjects Data Abstract
Current version: Data Abstract 'Vinci' (5.0)

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