public SqlIncluder Include(Func <EntityExpression, MemberExpression> selector, string alias = null)
{
if (_rootIncluder == null)
{
_rootIncluder = new SqlIncluder(T);
}
return(_rootIncluder.ThenInclude(selector, alias));
}
//public SqlIncluder ThenInclude(MemberExpression member, string alias = null)
//{
// return IncludeInternal(member, alias);
//}
private SqlIncluder IncludeInternal(MemberExpression member, string alias = null)
{
//检查当前是否Field，是则不再允许Include其他
if (MemberExpression.Type == ExpressionType.FieldExpression)
{
throw new NotSupportedException();
}
if (member.Type == ExpressionType.FieldExpression)
{
//可以包含多个层级如t.Customer.Region.Name
//if (!ReferenceEquals(GetTopOnwer(member), MemberExpression))
// throw new ArgumentException("Owner not same");
if (ReferenceEquals(member.Owner, MemberExpression))
{
throw new ArgumentException("Can't include field");
}
//判断alias空，是则自动生成eg:t.Customer.Region.Name => CustomerRegionName
if (string.IsNullOrEmpty(alias))
{
alias = member.GetFieldAlias();
}
//TODO:判断重复
if (Childs == null)
{
Childs = new List <SqlIncluder>();
}
var res = new SqlIncluder(this, new SqlSelectItemExpression(member, alias));
Childs.Add(res);
return(res);
}
else //EntityRef or EntitySet
{
Debug.Assert(member.Type == ExpressionType.EntityExpression ||
member.Type == ExpressionType.EntitySetExpression);
//判断Include的Owner是否相同
//if (!ReferenceEquals(member.Owner, MemberExpression))
// throw new ArgumentException("Owner not same");
if (Childs == null)
{
var child = new SqlIncluder(this, member);
Childs = new List <SqlIncluder> {
child
};
return(child);
}
var found = Childs.FindIndex(t => t.Expression.Type == member.Type &&
t.MemberExpression.Name == member.Name);
if (found >= 0)
{
return(Childs[found]);
}
var res = new SqlIncluder(this, member);
Childs.Add(res);
return(res);
}
}
/// <summary>
/// 仅用于加载EntitySet
/// </summary>
internal SqlQuery(SqlIncluder root)
{
T = ((EntitySetExpression)root.Expression).RootEntityExpression;
T.User = this;
_rootIncluder = root;
}
/// <summary>
/// 新建子级
/// </summary>
private SqlIncluder(SqlIncluder parent, Expression exp)
{
Parent = parent ?? throw new ArgumentNullException(nameof(parent));
Expression = exp;
}
