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

TCheckConstraint

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

Record-level constraint definition

Declaration

Source position: db.pas line 1084

type TCheckConstraint = class(TCollectionItem)

public

  procedure Assign(); override;

  

Assign one constraint to another

published

  property CustomConstraint: string; [rw]

  

User-defined constraint

  property ErrorMessage: string; [rw]

  

Message to display when the constraint is violated

  property FromDictionary: Boolean; [rw]

  

True if the constraint is imported from a datadictionary

  property ImportedConstraint: string; [rw]

  

Constraint imported from the database engine

end;

Inheritance

TCheckConstraint

  

Record-level constraint definition

|

TCollectionItem

|

TPersistent,IFPObserved

|

TObject

Description

TCheckConstraint can be used to store the definition of a record-level constraint. It does not enforce the constraint, it only stores the constraint's definition. The constraint can come from several sources: an imported constraints from the database, usually stored in the TCheckConstraint.ImportedConstraint property , or a constraint enforced by the user on a particular dataset instance stored in TCheckConstraint.CustomConstraint

See also

TCheckConstraints

  

Set of record-level constraints

TCheckConstraint.ImportedConstraint

  

Constraint imported from the database engine

TCheckConstraint.CustomConstraint

  

User-defined constraint


Documentation generated on: Jun 22 2020