/// <summary>
/// this method needs to be handled with much care.
/// First, the input list must not stem from a request finishing with a call to AsNoTracking method.
/// Second, the query from which the input stems must be closed properly.
/// This means that the result of a query must be cast to any kind of IEnumerable (List, Array)
/// which will close the preceding query.
/// </summary>
/// <param name="dbAccess"></param>
/// <param name="entities"></param>
/// <returns></returns>
public static DbResults <T> Delete <T, TId>(this DbContext dbAccess, IEnumerable <T> entities)
where T : BaseAuditable <TId>
{
var results = new DbResults <T>();
if (null != entities)
{
using var transaction = dbAccess.Database.BeginTransaction();
foreach (var entity in entities)
{
var result = new DbResult <T> {
Entity = entity
};
if (null == entity)
{
result.ResultCode = DbResultCode.EntityIsNull;
continue;
}
// Check 1: model has no unique key - skip
if (EqualityComparer <TId> .Default.Equals(entity.Id, default))
{
result.ResultCode = DbResultCode.Impractical;
continue;
}
// Check 2: model can be deleted
dbAccess.Entry(entity).State = EntityState.Deleted;
var changes = dbAccess.SaveChanges();
if (0 == changes || dbAccess.Entry(entity).State != EntityState.Detached)
{
result.ResultCode = DbResultCode.SaveFailed;
}
results.Results.Add(result);
}
if (results.Success)
{
transaction.Commit();
}
else
{
transaction.Rollback();
}
}
return(results);
}
public static DbResults <T> Create <T, TId>(this DbContext dbContext, IEnumerable <T> entities)
where T : BaseAuditable <TId>
{
var results = new DbResults <T>();
if (null != entities)
{
using var transaction = dbContext.Database.BeginTransaction();
foreach (var entity in entities)
{
var result = dbContext.CheckCreateEntity <T, TId>(entity);
if (result.Success)
{
dbContext.Entry(entity).State = EntityState.Added;
var changed = dbContext.SaveChanges();
var entityAdded = dbContext.Entry(entity).State == EntityState.Unchanged;
if (0 == changed || !entityAdded)
{
result.ResultCode |= DbResultCode.SaveFailed;
}
}
if (!result.Success)
{
dbContext.Entry(entity).State = EntityState.Detached;
}
results.Results.Add(result);
}
if (results.Success)
{
transaction.Commit();
}
else
{
transaction.Rollback();
}
}
return(results);
}