public static async Task BatchQuery(int batchSize, WhereDelegate <ListColumns> where, Action <IEnumerable <List> > batchProcessor, Database database = null)
{
await Task.Run(async() =>
{
ListColumns columns = new ListColumns();
var orderBy = Bam.Net.Data.Order.By <ListColumns>(c => c.KeyColumn, Bam.Net.Data.SortOrder.Ascending);
var results = Top(batchSize, where, orderBy, database);
while (results.Count > 0)
{
await Task.Run(() =>
{
batchProcessor(results);
});
long topId = results.Select(d => d.Property <long>(columns.KeyColumn.ToString())).ToArray().Largest();
results = Top(batchSize, (ListColumns) where (columns) && columns.KeyColumn > topId, orderBy, database);
}
});
}
public static ListCollection Top(int count, WhereDelegate <ListColumns> where, OrderBy <ListColumns> orderBy, Database database = null)
{
ListColumns c = new ListColumns();
IQueryFilter filter = where (c);
Database db = database ?? Db.For <List>();
QuerySet query = GetQuerySet(db);
query.Top <List>(count);
query.Where(filter);
if (orderBy != null)
{
query.OrderBy <ListColumns>(orderBy);
}
query.Execute(db);
var results = query.Results.As <ListCollection>(0);
results.Database = db;
return(results);
}
/// <summary>
/// Gets a query filter that should uniquely identify
/// the current instance. The default implementation
/// compares the Id/key field to the current instance.
/// </summary>
public override IQueryFilter GetUniqueFilter()
{
var colFilter = new ListColumns();
return(colFilter.Id == IdValue);
}
