4D v18
entitySelection[index]
- 4D Language Reference
-
- ORDA - EntitySelection
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- entitySelection.{attributeName}
- entitySelection.length
- entitySelection.queryPath
- entitySelection.queryPlan
- entitySelection[index]
- entitySelection.or( )
- entitySelection.orderBy( )
- entitySelection.drop( )
- entitySelection.query( )
- entitySelection.add( )
- entitySelection.isOrdered( )
- entitySelection.minus( )
- entitySelection.first( )
- entitySelection.last( )
- entitySelection.toCollection( )
- entitySelection.contains( )
- entitySelection.and( )
- entitySelection.sum( )
- entitySelection.count( )
- entitySelection.min( )
- entitySelection.max( )
- entitySelection.slice( )
- entitySelection.distinct( )
- entitySelection.average( )
- entitySelection.getDataClass( )
- entitySelection.orderByFormula( )
- Create entity selection
- USE ENTITY SELECTION
entitySelection[index]
| Parameter | Type | Description | ||||||
| entitySelection[index] | Entity |
|
Entity corresponding to the specified index (non assignable expression) | |||||
The entitySelection[index] notation allows you to access entities within the entity selection using the standard collection syntax: pass the position of the entity you want to get in the index parameter.
Note that the corresponding entity is reloaded from the datastore.
index can be any number between 0 and entitySelection.length-1.
- If index is out of range, an error is returned.
- If index corresponds to a dropped entity, a Null value is returned.
Warning: entitySelection[index] is a non assignable expression, which means that it cannot be used as en editable entity reference with methods like entity.lock( ) or entity.save( ). To work with the corresponding entity, you need to assign the returned expression to an assignable expression, such as a variable. Examples:
$sel:=ds.Employee.all() //create the entity selection
//invalid statements:
$result:=$sel[0].lock() //will NOT work
$sel[0].lastName:="Smith" //will NOT work
$result:=$sel[0].save() //will NOT work
//valid code:
$entity:=$sel[0] //OK
$entity.lastName:="Smith" //OK
$entity.save() //OK C_OBJECT($employees;$employee)
$employees:=ds.Employee.query("lastName = :1";"H@")
$employee:=$employees[2] // The 3rd entity of the $employees entity selection is reloaded from the database
Product: 4D
Theme: ORDA - EntitySelection
Created: 4D v17
4D Language Reference ( 4D v18)
