public UnionContext(SubQueryContext sequence1, SubQueryContext sequence2, MethodCallExpression methodCall)
: base(sequence1)
{
_sequence1 = sequence1;
_sequence2 = sequence2;
_methodCall = methodCall;
_sequence2.Parent = this;
_isObject =
sequence1.IsExpression(null, 0, RequestFor.Object).Result ||
sequence2.IsExpression(null, 0, RequestFor.Object).Result;
if (_isObject)
{
_type = _methodCall.Method.GetGenericArguments()[0];
_unionParameter = Expression.Parameter(_type, "t");
}
Init();
}
void Init()
{
var info1 = _sequence1.ConvertToIndex(null, 0, ConvertFlags.All).ToList();
var info2 = _sequence2.ConvertToIndex(null, 0, ConvertFlags.All).ToList();
if (!_isObject)
{
return;
}
var members = new List <UnionMember>();
foreach (var info in info1)
{
if (info.Members.Count == 0)
{
throw new InvalidOperationException();
}
var member = new Member
{
SequenceInfo = info,
MemberExpression = Expression.MakeMemberAccess(_unionParameter, info.Members[0])
};
members.Add(new UnionMember {
Member = member, Info1 = info
});
}
foreach (var info in info2)
{
if (info.Members.Count == 0)
{
throw new InvalidOperationException();
}
var em = members.FirstOrDefault(m =>
m.Member.SequenceInfo != null &&
m.Member.SequenceInfo.CompareLastMember(info));
if (em == null)
{
var member = new Member {
MemberExpression = Expression.MakeMemberAccess(_unionParameter, info.Members[0])
};
if (_sequence2.IsExpression(member.MemberExpression, 1, RequestFor.Object).Result)
{
throw new LinqException("Types in {0} are constructed incompatibly.", _methodCall.Method.Name);
}
members.Add(new UnionMember {
Member = member, Info2 = info
});
}
else
{
em.Info2 = info;
}
}
_sequence1.SelectQuery.Select.Columns.Clear();
_sequence2.SelectQuery.Select.Columns.Clear();
for (var i = 0; i < members.Count; i++)
{
var member = members[i];
if (member.Info1 == null)
{
member.Info1 = new SqlInfo(member.Info2.Members)
{
Sql = new SqlValue(null),
Query = _sequence1.SelectQuery,
};
member.Member.SequenceInfo = member.Info1;
}
if (member.Info2 == null)
{
member.Info2 = new SqlInfo(member.Info1.Members)
{
Sql = new SqlValue(null),
Query = _sequence2.SelectQuery,
};
}
_sequence1.SelectQuery.Select.Columns.Add(new SelectQuery.Column(_sequence1.SelectQuery, member.Info1.Sql));
_sequence2.SelectQuery.Select.Columns.Add(new SelectQuery.Column(_sequence2.SelectQuery, member.Info2.Sql));
member.Member.SequenceInfo.Index = i;
_members[member.Member.MemberExpression.Member] = member.Member;
}
foreach (var key in _sequence1.ColumnIndexes.Keys.ToList())
{
_sequence1.ColumnIndexes[key] = _sequence1.SelectQuery.Select.Add(key);
}
foreach (var key in _sequence2.ColumnIndexes.Keys.ToList())
{
_sequence2.ColumnIndexes[key] = _sequence2.SelectQuery.Select.Add(key);
}
}