IDADataset
Overview
The IDADataset interface is used as source for data retrieval on client-side.
For server-side, see IDAServerDataset.
Location
- Unit: uDAInterfaces.pas
- Ancestry: IDADataset
Active
Specifies whether the dataset is currently active (open) or not. Setting this property to true will automatically open the dataset, while setting it to false will automatically close it.
property Active: Boolean read write
Close safecall
Closes the dataset
procedure Close
ControlsDisabled safecall
Indicates whether data-aware controls update their display to reflect changes to the dataset.
function ControlsDisabled: Boolean
CurrentRecIdValue
Returns identificator of current record.
property CurrentRecIdValue: Integer read write
Dataset
Access to the standard VCL TDataSet
property Dataset: TDataSet read
DisableConstraints safecall
Disables dataset constraints
procedure DisableConstraints
DisableControls safecall
Disables data display in data-aware controls associated with the dataset.
procedure DisableControls
DynamicWhere
Implementation of Dynamic Where.
property DynamicWhere: TDAWhereBuilder read write
EnableConstraints safecall
Enables dataset constraints
procedure EnableConstraints
EnableControls safecall
Enables data display in data-aware controls associated with the dataset.
procedure EnableControls
Eof
Indicates whether reading the dataset has reached the end of the recordset (EOF = End of File). EOF will only turn true if neither an empty dataset was opened or Next was called while the cursor was already on the last record (it will not turn to true when reaching the last record).
property Eof: Boolean read
FieldByName safecall
Finds a field based on its name. If the specified field does not exist, FieldByName raises an exception.
function FieldByName(const aName: string): TDAField
Parameters:
- aName: name of the searched field
FieldCount
Indicates the number of fields contained in the dataset.
property FieldCount: Integer read
Fields
Provides access to all the fields contained in the dataset.
property Fields: TDAFieldCollection read
FieldValues
Provides convenient access to all the fields values of the current record without having to go though the Fields collection property.
property FieldValues[Index: Integer]: Variant read
FindField safecall
Returns an item with the specified name.
function FindField(const aName: string): TDAField
Parameters:
- aName: name of the searched field
IsEmpty
Indicates whether the dataset contains no records.
property IsEmpty: Boolean read
Locate safecall
Locates and activates a record by key values.
function Locate(const KeyFields: string; const KeyValues: Variant; Options: TLocateOptions): Boolean
Parameters:
- KeyFields: The semicolon-separated list of fields.
- KeyValues: Values specified by the Variant or Variant array.
- Options: Indicates whether the search is case insensitive and whether partial matches are supported.
LogicalName
Defines the name of the data table.
property LogicalName: string read write
Lookup safecall
Retrieves the field values from the record that matches the specified search values.
function Lookup(const KeyFields: string; const KeyValues: Variant; const ResultFields: string): Variant
Parameters:
- KeyFields: the semicolon-separated list of fields
- KeyValues: Values specified by the Variant or Variant array.
- ResultFields: The semicolon-separated list of result fields.
Name
Returns a human-readable name for the command. For commands obtained through a TDASchema component, this will be the name that the command (or data table) was defined under in Schema Modeler. When obtaining a command from an IDAConnection, the name can be specified in the call to NewCommand or NewDataset.
property Name: string read
Names
Returns data table's field name specified by Index
property Names[Index: Integer]: string read
Next safecall
Advances the cursor to the next available record in the dataset. If the current record is the last record available, calling Next will set EOF to indicate the end of the dataset has been reached.
procedure Next
OnAfterOpen
Fires after dataset was opened
property OnAfterOpen: TDAAfterOpenDatasetEvent read write
delegate: procedure OnAfterOpen(const Sender: IDADataset; ActualSQL: string; ElapsedMilliseconds: Cardinal)
OnBeforeOpen
Fires before dataset was opened
property OnBeforeOpen: TDABeforeOpenDatasetEvent read write
delegate: procedure OnBeforeOpen(const Sender: IDADataset)
Open safecall
Opens the dataset and prepares it for fetching records from the database.
procedure Open
ParamByName safecall
Locates a specific parameter, based on its name. If no matching parameter is defined, an exception will be raised.
function ParamByName(const aName: string): TDAParam
Parameters:
- aName: name of the parameter
Params
Provides access to the list of parameters defined for the command.
property Params: TDAParamCollection read
RecordCount
Returns the counf of records
property RecordCount: Integer read
RowRecIdValue
Returns record ID
property RowRecIdValue: Integer read
Active
Specifies whether the dataset is currently active (open) or not. Setting this property to true will automatically open the dataset, while setting it to false will automatically close it.
property Active: Boolean read write
CurrentRecIdValue
Returns identificator of current record.
property CurrentRecIdValue: Integer read write
Dataset
Access to the standard VCL TDataSet
property Dataset: TDataSet read
DynamicWhere
Implementation of Dynamic Where.
property DynamicWhere: TDAWhereBuilder read write
Eof
Indicates whether reading the dataset has reached the end of the recordset (EOF = End of File). EOF will only turn true if neither an empty dataset was opened or Next was called while the cursor was already on the last record (it will not turn to true when reaching the last record).
property Eof: Boolean read
FieldCount
Indicates the number of fields contained in the dataset.
property FieldCount: Integer read
Fields
Provides access to all the fields contained in the dataset.
property Fields: TDAFieldCollection read
FieldValues
Provides convenient access to all the fields values of the current record without having to go though the Fields collection property.
property FieldValues[Index: Integer]: Variant read
IsEmpty
Indicates whether the dataset contains no records.
property IsEmpty: Boolean read
LogicalName
Defines the name of the data table.
property LogicalName: string read write
Name
Returns a human-readable name for the command. For commands obtained through a TDASchema component, this will be the name that the command (or data table) was defined under in Schema Modeler. When obtaining a command from an IDAConnection, the name can be specified in the call to NewCommand or NewDataset.
property Name: string read
Names
Returns data table's field name specified by Index
property Names[Index: Integer]: string read
Params
Provides access to the list of parameters defined for the command.
property Params: TDAParamCollection read
RecordCount
Returns the counf of records
property RecordCount: Integer read
RowRecIdValue
Returns record ID
property RowRecIdValue: Integer read
Close safecall
Closes the dataset
procedure Close
ControlsDisabled safecall
Indicates whether data-aware controls update their display to reflect changes to the dataset.
function ControlsDisabled: Boolean
DisableConstraints safecall
Disables dataset constraints
procedure DisableConstraints
DisableControls safecall
Disables data display in data-aware controls associated with the dataset.
procedure DisableControls
EnableConstraints safecall
Enables dataset constraints
procedure EnableConstraints
EnableControls safecall
Enables data display in data-aware controls associated with the dataset.
procedure EnableControls
FieldByName safecall
Finds a field based on its name. If the specified field does not exist, FieldByName raises an exception.
function FieldByName(const aName: string): TDAField
Parameters:
- aName: name of the searched field
FindField safecall
Returns an item with the specified name.
function FindField(const aName: string): TDAField
Parameters:
- aName: name of the searched field
Locate safecall
Locates and activates a record by key values.
function Locate(const KeyFields: string; const KeyValues: Variant; Options: TLocateOptions): Boolean
Parameters:
- KeyFields: The semicolon-separated list of fields.
- KeyValues: Values specified by the Variant or Variant array.
- Options: Indicates whether the search is case insensitive and whether partial matches are supported.
Lookup safecall
Retrieves the field values from the record that matches the specified search values.
function Lookup(const KeyFields: string; const KeyValues: Variant; const ResultFields: string): Variant
Parameters:
- KeyFields: the semicolon-separated list of fields
- KeyValues: Values specified by the Variant or Variant array.
- ResultFields: The semicolon-separated list of result fields.
Next safecall
Advances the cursor to the next available record in the dataset. If the current record is the last record available, calling Next will set EOF to indicate the end of the dataset has been reached.
procedure Next
Open safecall
Opens the dataset and prepares it for fetching records from the database.
procedure Open
ParamByName safecall
Locates a specific parameter, based on its name. If no matching parameter is defined, an exception will be raised.
function ParamByName(const aName: string): TDAParam
Parameters:
- aName: name of the parameter
OnAfterOpen
Fires after dataset was opened
property OnAfterOpen: TDAAfterOpenDatasetEvent read write
delegate: procedure OnAfterOpen(const Sender: IDADataset; ActualSQL: string; ElapsedMilliseconds: Cardinal)
OnBeforeOpen
Fires before dataset was opened
property OnBeforeOpen: TDABeforeOpenDatasetEvent read write
delegate: procedure OnBeforeOpen(const Sender: IDADataset)
- IDAConnection and TDASchema methods.
- Database Drivers