Sample Trigger:
trigger CaseTrigger on Case ( before update ) {
Set < Id > setCaseIds = new Set < Id >();
Map < Id, Integer > mapOpenCaseCount = new Map < Id, Integer >();
for ( Case objCase : trigger.new ) {
if ( objCase.Status == ‘Closed’ ) {
setCaseIds.add( objCase.Id );
}
}
for ( Case objCase : [ SELECT ParentId FROM Case WHERE ParentId IN: setCaseIds AND IsClosed = false ] ) {
if ( mapOpenCaseCount.containsKey( objCase.ParentId ) ) {
mapOpenCaseCount.put( objCase.ParentId, mapOpenCaseCount.get( objCase.ParentId ) + 1 );
} else {
mapOpenCaseCount.put( objCase.ParentId, 1 );
}
}
for ( Case objCase : trigger.new ) {
if ( objCase.Status == ‘Closed’ ) {
if ( mapOpenCaseCount.containsKey( objCase.Id ) ) {
objCase.addError( ‘You cannot close this Case. It has ‘ + mapOpenCaseCount.get( objCase.Id ) + ‘ open Child Cases.’ );
}
}
}
}
Sample Case record with two open Child Cases
Trigger Valiation Error:
