TDANullExpression
Overview
The TDANullExpression class is a descendant of the TDAWhereExpression class representing a NULL value.
Location
- Unit: uDAWhere.pas
- Ancestry: TDAWhereExpression | TDANullExpression
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
GetWhereKind protected override
function GetWhereKind: TDAWhereKind
Kind (declared in TDAWhereExpression)
property Kind: TDAWhereKind read
ParseException protected (declared in TDAWhereExpression)
Raises EDAWhereParseXmlException.
procedure ParseException(aName: string)
Parameters:
- aName: property name.
ParseExpression (IXmlNode, string): TDAWhereExpression protected overload (declared in TDAWhereExpression)
Calls ParseException if xr is nil, otherwise calls overload ParseException.
function ParseExpression(xr: IXmlNode; aName: string): TDAWhereExpression
Parameters:
- xr: source node.
- aName: Name of property
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.
ReadFromXml override
Reads where expression from the XML.
procedure ReadFromXml(xr: IXmlNode)
Parameters:
- xr: source node
RemoveEmptyNodes (declared in TDAWhereExpression)
class procedure RemoveEmptyNodes(aNode: IXMLNode)
Parameters:
- aNode:
Validate virtual (declared in TDAWhereExpression)
Validates properties of expression.
procedure Validate
WriteToXml override
Writes where expression to the XML.
procedure WriteToXml(sw: IXmlNode)
Parameters:
- sw: destination node
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)
class procedure RemoveEmptyNodes(aNode: IXMLNode)
Parameters:
- aNode:
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
GetWhereKind protected override
function GetWhereKind: TDAWhereKind
ParseException protected (declared in TDAWhereExpression)
Raises EDAWhereParseXmlException.
procedure ParseException(aName: string)
Parameters:
- aName: property name.
ParseExpression (IXmlNode, string): TDAWhereExpression protected overload (declared in TDAWhereExpression)
Calls ParseException if xr is nil, otherwise calls overload ParseException.
function ParseExpression(xr: IXmlNode; aName: string): TDAWhereExpression
Parameters:
- xr: source node.
- aName: Name of property
ReadFromXml override
Reads where expression from the XML.
procedure ReadFromXml(xr: IXmlNode)
Parameters:
- xr: source node
Validate virtual (declared in TDAWhereExpression)
Validates properties of expression.
procedure Validate
WriteToXml override
Writes where expression to the XML.
procedure WriteToXml(sw: IXmlNode)
Parameters:
- sw: destination node