TParam¶

Parameter description class.

Declaration¶

Source position: db.pas line 1389

type

  TParam = class(TCollectionItem)
  public
    constructor Create(ACollection: TCollection); overload;
    constructor Create(AParams: TParams; AParamType: TParamType); overload;
    procedure Assign;
    procedure AssignField;
    procedure AssignToField;
    procedure AssignFieldValue;
    procedure AssignFromField;
    procedure Clear;
    procedure GetData;
    function GetDataSize : Integer;
    procedure LoadFromFile;
    procedure LoadFromStream;
    procedure SetBlobData;
    procedure SetData;
    property AsBCD: Currency; {rw}
    property AsBlob: TBlobData; {rw}
    property AsBoolean: Boolean; {rw}
    property AsByte: LongInt; {rw}
    property AsBytes: TBytes; {rw}
    property AsCurrency: Currency; {rw}
    property AsDate: TDateTime; {rw}
    property AsDateTime: TDateTime; {rw}
    property AsFloat: Double; {rw}
    property AsInteger: LongInt; {rw}
    property AsLargeInt: LargeInt; {rw}
    property AsLongWord: LongWord; {rw}
    property AsMemo: string; {rw}
    property AsShortInt: LongInt; {rw}
    property AsSingle: Single; {rw}
    property AsSmallInt: LongInt; {rw}
    property AsString: string; {rw}
    property AsAnsiString: AnsiString; {rw}
    property AsUTF8String: UTF8String; {rw}
    property AsUnicodeString: UnicodeString; {rw}
    property AsTime: TDateTime; {rw}
    property AsWord: LongInt; {rw}
    property AsFMTBCD: TBCD; {rw}
    property Bound: Boolean; {rw}
    property Dataset: TDataSet; {r}
    property IsNull: Boolean; {r}
    property NativeStr: string; {rw}
    property Text: string; {rw}
    property AsWideString: WideString; {rw}
  published
    property DataType: TFieldType; {rw}
    property Name: string; {rw}
    property NumericScale: Integer; {rwd}
    property ParamType: TParamType; {rw}
    property Precision: Integer; {rwd}
    property Size: Integer; {rwd}
    property Value: Variant; {rws}
  end;

Inheritance¶

Description¶

TParam is one item in a TParams collection. It describes the name (TParam.Name), type (ParamType) and value (TParam.Value) of a parameter in a parameterized query or stored procedure. Under normal circumstances, it should never be necessary to create a TParam instance manually; the TDataset descendent that owns the parameters should have created all necessary TParam instances.

Properties¶

Member	Visibility	Description
AsAnsiString	public	Parameter contents as an ANSI string.
AsBCD	public	Get or set parameter value as BCD value.
AsBlob	public	Return parameter value as a blob.
AsBoolean	public	Get/Set parameter value as a boolean value.
AsByte	public	Get/Set parameter value as a 8-bit unsigned integer value.
AsBytes	public	Get or set parameter value as TBytes.
AsCurrency	public	Get/Set parameter value as a currency value.
AsDate	public	Get/Set parameter value as a date (TDateTime) value.
AsDateTime	public	Get/Set parameter value as a date/time (TDateTime) value.
AsFloat	public	Get/Set parameter value as a floating-point value.
AsFMTBCD	public	Parameter value as a BCD value.
AsInteger	public	Get/Set parameter value as an integer (32-bit) value.
AsLargeInt	public	Get/Set parameter value as a 64-bit integer value.
AsLongWord	public	Get/Set parameter value as a 32-bit unsigned integer value.
AsMemo	public	Get/Set parameter value as a memo (string) value.
AsShortInt	public
AsSingle	public
AsSmallInt	public	Get/Set parameter value as a smallint value.
AsString	public	Get/Set parameter value as a string value.
AsTime	public	Get/Set parameter value as a time (TDateTime) value.
AsUnicodeString	public	Parameter contents as a Unicode string.
AsUTF8String	public	Parameter contents as an UTF8 string.
AsWideString	public	Get/Set the value as a widestring.
AsWord	public	Get/Set parameter value as a word value.
Bound	public	Is the parameter value bound (set to fixed value).
Dataset read only	public	Dataset to which this parameter belongs.
DataType	published	Data type of the parameter.
IsNull read only	public	Is the parameter empty.
Name	published	Name of the parameter.
NativeStr	public	No description available.
NumericScale	published	Numeric scale.
ParamType	published	Type of parameter.
Precision	published	Precision of the BCD value.
Size	published	Size of the parameter.
Text	public	Read or write the value of the parameter as a string.
Value	published	Value as a variant.

See all Properties

Methods¶

Member	Visibility	Description
Assign	public	Assign one parameter instance to another.
AssignField	public	Copy value from field instance.
AssignFieldValue	public	Assign field value to the parameter.
AssignFromField	public	Copy field type and value.
AssignToField	public	Assign parameter value to field.
Clear	public	Clear the parameter value.
Create	public	Create a new parameter value.
GetData	public	Get the parameter value from a memory buffer.
GetDataSize	public	Return the size of the data.
LoadFromFile	public	Load a parameter value from file.
LoadFromStream	public	Load a parameter value from stream.
SetBlobData	public	Set BLOB data.
SetData	public	Set the parameter value from a buffer.

See all Methods