TDAFieldExpression

Overview

The TDAFieldExpression class is a descendant of the TDAWhereExpression and introduces the part of the expression containing the field name and possibly the table name.

Location

 

constructor Create (string, string)  overload

Creates a new expression.

constructor Create(const aTableName: string; const aFieldName: string)

Parameters:

  • aTableName: Name of the table.
  • aFieldName: Name of the database field.

AsJson    (declared in TDAWhereExpression)

Returns where expression in Json format

function AsJson: UnicodeString

AsXML    (declared in TDAWhereExpression)

Returns where expression in XML format

function AsXML: UnicodeString

Clone  override

function Clone: TDAWhereExpression

DoValidate  protected    (declared in TDAWhereExpression)

Raised exception if aRaiseException is set

procedure DoValidate(aRaiseException: Boolean; aName: string)

Parameters:

  • aRaiseException: specifies should the exception be raised or not.
  • aName: Name of property

FieldName

Name of the database field represented by this instance.

property FieldName: string read write

Kind    (declared in TDAWhereExpression)

Specified kind of TDAWhereExpression

property Kind: TDAWhereKind read

ParseException  protected    (declared in TDAWhereExpression)

Raises EDAWhereParseXmlException.

procedure ParseException(aName: string)

Parameters:

  • aName: property name.

ParseExpression (TROJSONObject, string): TDAWhereExpression  protected overload    (declared in TDAWhereExpression)

Creates new Where expression from Json object.

function ParseExpression(aItem: TROJSONObject; aName: string): TDAWhereExpression

Parameters:

  • aItem: Json object
  • aName: Name of property

ParseExpression (IXmlNode, string): TDAWhereExpression  protected overload    (declared in TDAWhereExpression)

Creates new Where expression from XML node.

function ParseExpression(xr: IXmlNode; aName: string): TDAWhereExpression

Parameters:

  • xr: source node.
  • aName: Name of property

ParseExpression (TROJSONObject): TDAWhereExpression  overload    (declared in TDAWhereExpression)

Creates new Where expression from Json object.

class function ParseExpression(anItem: TROJSONObject): TDAWhereExpression

Parameters:

  • anItem: json object

ParseExpression (IXmlNode): TDAWhereExpression  overload    (declared in TDAWhereExpression)

Creates new Where expression from XML node.

class function ParseExpression(xr: IXmlNode): TDAWhereExpression

Parameters:

  • xr: given XML node.

ReadFromJson  override

Reads where expression from the Json.

procedure ReadFromJson(aItem: TROJSONObject)

Parameters:

  • aItem: Json object

ReadFromXml  override

Reads where expression from the XML.

procedure ReadFromXml(xr: IXmlNode)

Parameters:

  • xr: source node

RemoveEmptyNodes    (declared in TDAWhereExpression)

Removes empty XML nodes from given node

class procedure RemoveEmptyNodes(aNode: IXMLNode)

Parameters:

  • aNode: node

TableName

Name of the table which the field belongs to.

property TableName: string read write

Validate  override

Validates properties of expression.

procedure Validate

WriteToJson  override

Writes where expression to the Json object.

procedure WriteToJson(aItem: TROJSONObject)

Parameters:

  • aItem: destination object

WriteToXml  override

Writes where expression to the XML node.

procedure WriteToXml(sw: IXmlNode)

Parameters:

  • sw: destination node

 

FieldName

Name of the database field represented by this instance.

property FieldName: string read write

Kind    (declared in TDAWhereExpression)

Specified kind of TDAWhereExpression

property Kind: TDAWhereKind read

TableName

Name of the table which the field belongs to.

property TableName: string read write

 

ParseExpression (TROJSONObject): TDAWhereExpression  overload    (declared in TDAWhereExpression)

Creates new Where expression from Json object.

class function ParseExpression(anItem: TROJSONObject): TDAWhereExpression

Parameters:

  • anItem: json object

ParseExpression (IXmlNode): TDAWhereExpression  overload    (declared in TDAWhereExpression)

Creates new Where expression from XML node.

class function ParseExpression(xr: IXmlNode): TDAWhereExpression

Parameters:

  • xr: given XML node.

RemoveEmptyNodes    (declared in TDAWhereExpression)

Removes empty XML nodes from given node

class procedure RemoveEmptyNodes(aNode: IXMLNode)

Parameters:

  • aNode: node

 

constructor Create (string, string)  overload

Creates a new expression.

constructor Create(const aTableName: string; const aFieldName: string)

Parameters:

  • aTableName: Name of the table.
  • aFieldName: Name of the database field.

AsJson    (declared in TDAWhereExpression)

Returns where expression in Json format

function AsJson: UnicodeString

AsXML    (declared in TDAWhereExpression)

Returns where expression in XML format

function AsXML: UnicodeString

Clone  override

function Clone: TDAWhereExpression

DoValidate  protected    (declared in TDAWhereExpression)

Raised exception if aRaiseException is set

procedure DoValidate(aRaiseException: Boolean; aName: string)

Parameters:

  • aRaiseException: specifies should the exception be raised or not.
  • aName: Name of property

ParseException  protected    (declared in TDAWhereExpression)

Raises EDAWhereParseXmlException.

procedure ParseException(aName: string)

Parameters:

  • aName: property name.

ParseExpression (TROJSONObject, string): TDAWhereExpression  protected overload    (declared in TDAWhereExpression)

Creates new Where expression from Json object.

function ParseExpression(aItem: TROJSONObject; aName: string): TDAWhereExpression

Parameters:

  • aItem: Json object
  • aName: Name of property

ParseExpression (IXmlNode, string): TDAWhereExpression  protected overload    (declared in TDAWhereExpression)

Creates new Where expression from XML node.

function ParseExpression(xr: IXmlNode; aName: string): TDAWhereExpression

Parameters:

  • xr: source node.
  • aName: Name of property

ReadFromJson  override

Reads where expression from the Json.

procedure ReadFromJson(aItem: TROJSONObject)

Parameters:

  • aItem: Json object

ReadFromXml  override

Reads where expression from the XML.

procedure ReadFromXml(xr: IXmlNode)

Parameters:

  • xr: source node

Validate  override

Validates properties of expression.

procedure Validate

WriteToJson  override

Writes where expression to the Json object.

procedure WriteToJson(aItem: TROJSONObject)

Parameters:

  • aItem: destination object

WriteToXml  override

Writes where expression to the XML node.

procedure WriteToXml(sw: IXmlNode)

Parameters:

  • sw: destination node