static int DefaultNewIdGenerator(Type type)
{
if (type.BaseType != typeof(IntEntity))
{
return(DefaultNewIdGenerator(type.BaseType));
}
Func <Type, int> initialize = (t =>
{
if (TransientEntityAttribute.IsTransient(t))
{
return(1);
}
return(Database.GetList(t, new[] { QueryOption.Take(1), QueryOption.OrderByDescending("ID") })
.FirstOrDefault().Get(x => (int)x.GetId() + 1) ?? 1);
});
return(LastUsedIds.AddOrUpdate(type, initialize, (t, old) => old + 1));
}
/// <summary>
/// Finds an object with the specified type matching the specified criteria.
/// If not found, it returns null.
/// </summary>
public static T Find <T>(Expression <Func <T, bool> > criteria, params QueryOption[] options) where T : IEntity
{
options = options ?? new QueryOption[0];
options = options.Concat(QueryOption.Take(1)).ToArray();
return(GetList <T>(criteria, options).FirstOrDefault());
}
/// <summary>
/// Find an object with the specified type from the database.
/// When used with no criteria, returns the first object found of the specified type.
/// If not found, it returns null.
/// </summary>
/// <param name="orderBy">The order by expression to run at the database level. It supports only one property.</param>
/// <param name="desc">Specified whether the order by is descending.</param>
public static T Find <T>(Expression <Func <T, bool> > criteria, Expression <Func <T, object> > orderBy, bool desc = false) where T : IEntity
{
return(GetList <T>(criteria, QueryOption.OrderBy <T>(orderBy, desc), QueryOption.Take(1)).FirstOrDefault());
}
/// <summary>
/// Find an object with the specified type from the database.
/// When used with no criteria, returns the first object found of the specified type.
/// If not found, it returns null.
/// </summary>
public static T Find <T>(params Criterion[] criteria) where T : IEntity
{
return(GetList <T>(criteria, QueryOption.Take(1)).FirstOrDefault());
}
