EntityDAC

TCustomEntityContext.GetEntity Method

The method is designed for retrieving an existing entity instance by specified criteria.

Class

TCustomEntityContext

Syntax

function GetEntity(EntityClass: TMappedEntityClass; const Condition: TExpression): TMappedEntity; overload;

Parameters
EntityClass
The class type of the entity to be retrieved.
Condition
The logical expression that defines the condition which the selected entitiy must conform.

Remarks

The method returns an entity instance of the specified meta-type selected by the specified conditional expression. The entity instance created by this method is initially attached to the data context and placed to the object cache (in contrast to the TCustomEntityContext.CreateEntity method), therefore you can already perform modification operations for the instance: TCustomEntityContext.Delete, TCustomEntityContext.Cancel) without pre-calling TCustomEntityContext.Attach. In addition, this entity instance will be automatically destroyed, and there will be no need to provide for its manual destruction.

Example

Examples of calling the method:

var
  EmpType: IMetaType;
  EmpEntity: TEmp;
begin
  EmpType := Context['Emp'];
  EmpEntity := Context.GetEntity(EmpType, EmpType['EmpNo'] = 1) as TEmp;
  // ...
end; 

See Also

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