[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'DB' (#fcl)

# TMasterParamsDataLink

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

Class to establish a master-detail relationship between dataset, based on parameters

## Declaration

Source position: db.pas line 1882

`type TMasterParamsDataLink = class(TMasterDataLink)`
`public`
`constructor Create(); override;` |  | Initialize a new TMasterParamsDataLink instance
`procedure RefreshParamNames; virtual;` |  | Refresh the list of parameter names
`procedure CopyParamsFromMaster(); virtual;` |  | Copy parameter values from master dataset.
`property Params: TParams; [rw]` |  | Parameters of detail dataset.
`end;`

## Inheritance

`TMasterParamsDataLink` |  | Class to establish a master-detail relationship between dataset, based on parameters
`TMasterDataLink` |  | Datalink for Master-Detail relationships between datasets.
`TDetailDataLink` |  | Represents the link between a detail data source and a master datasource.
`TDataLink` |  | Data event handling agent for controls
`TPersistent,IFPObserved`
`TObject`

## Description

TMasterParamsDataLink is a TDataLink descendent that can be used to establish a master-detail relationship between 2 TDataset instances where the detail dataset is parameterized using a TParams instance. It takes care of closing and opening the detail dataset and copying the parameter values from the master dataset whenever the data in the master dataset changes.

## See also

TDatalink |  | Data event handling agent for controls
TDataset |  | Base class for records-based data-access
TParams |  | A collection of parameter values for SQL-based datasets
TParam |  | Parameter description class