LINQ2SQL: How to let a column accept null values as zero (0) in Self-Relation table
- by Remon
As described in the img, I got a parent-Children relation and since the ParentID not accepting null values (and I can't change to nullabel due to some restriction in the UI I have), how can I remove an existence relation between ReportDataSources in order to change the parent for them (here i want to set the parentId for one of them = 0) how could i do that since i cant change the ParentID directly and setting Parent = null is not valid
public void SetReportDataSourceAsMaster(ReportDataSource reportDataSource)
{
//Some logic - not necessarily for this scenario
//Reset Master
this.ReportDataSources.ToList().ForEach(rds => rds.IsMaster = false);
//Set Master
reportDataSource.IsMaster = true;
//Set Parent ID for the rest of the Reports data sources
this.ReportDataSources.Where(rds => rds.ID != reportDataSource.ID).ToList().ForEach(rds =>
{
//Change Parent ID
rds.Parent = reportDataSource;
//Remove filttering data
rds.FilteringDataMembers.Clear();
//Remove Grouping Data
rds.GroupingDataMembers.Clear();
});
//Delete parent HERE THE EXCEPTION THROWN AFTER CALLING SUBMITCHANGES()
reportDataSource.Parent = null;
//Other logic
}
Exception thrown after calling submitChanges An attempt was made to remove a relationship between a ReportDataSource and a ReportDataSource. However, one of the relationship's foreign keys (ReportDataSource.ParentID) cannot be set to null.
