private void AutoJoin(JoinChainer source)
{
if (!source.HasNode)
{
throw JoinerException(source, (TableChainer)null, QueryTalkExceptionType.InvalidJoinTable);
}
bool found = false;
TableChainer target = null;
var ix = _targets.Count - 1;
while (ix >= 0)
{
target = _targets[ix];
if (CheckAutoTarget(source, target))
{
found = true;
break;
}
--ix;
}
if (!found)
{
throw JoinerAutoJoinFailedException(source);
}
var expression = _GetMappedExpression(source, target, DB3.Default);
_InjectOn(source, expression);
source.AppendJoinGraph(target.JoinGraph);
}
private Expression AliasByJoin(JoinChainer source, ByArgument arg)
{
var target = _GetTargetByAlias(source, arg.Alias, true);
if (!source.HasNode || !target.HasNode)
{
throw JoinerException(source, target, QueryTalkExceptionType.InvalidJoinTable);
}
var expression = _GetMappedExpression(source, target, DB3.Default);
source.AppendJoinGraph(target.JoinGraph);
return(expression);
}
private TableChainer _GetTargetByAlias(JoinChainer source, string alias, bool hasNodeCheck)
{
foreach (var target in _targets)
{
if (target.Alias.Name.EqualsCS(alias))
{
if (hasNodeCheck && !target.HasNode)
{
throw JoinerException(source, alias, QueryTalkExceptionType.JoinTargetNotMapped);
}
return(target);
}
}
throw JoinerException(source, alias, QueryTalkExceptionType.JoinTargetNotFound);
}
private void ByJoin(JoinChainer source)
{
Expression expression = null;
Expression part = null;
var i = 0;
foreach (var arg in source.ByArguments)
{
switch (arg.JoinType)
{
case ByType.Alias:
part = AliasByJoin(source, arg);
break;
case ByType.NonMappedColumn:
part = NonMappedByJoin(source, arg);
break;
case ByType.MappedColumn:
part = MappedByJoin(source, arg);
break;
}
if (i == 0)
{
expression = part;
}
else
{
expression = expression.And(part);
}
++i;
}
_InjectOn(source, expression);
}
private TableChainer _InjectJoinBy(DbNode node, string alias)
{
Chainer last = _tables[_tables.Count - 1];
Chainer next;
// skip .As
if (last.Next is AliasAs)
{
last = last.Next;
}
// skip .On/.By
if (last.Next is OnChainer || last.Next is ByChainer)
{
last = last.Next;
}
next = last.Next;
// inject .Join.By
var nodeToInsert = new InternalNode(node);
// pass FK to support multiple relations in column graph - !
((IRelation)nodeToInsert).FK = node.GetFK();
var by = ((ISemqJoin)last).Join(nodeToInsert).By(alias);
by.SetNext(next);
// add injected
JoinChainer source = (JoinChainer)_tables[_tables.Count - 1];
_targets.Add(source);
ByJoin(source);
return(source);
}
private static void _InjectOn(JoinChainer source, Expression expression)
{
Chainer prevOfOn = source;
Chainer nextOfOn;
// skip .As
if (source.Next is AliasAs)
{
prevOfOn = source.Next;
}
nextOfOn = prevOfOn.Next;
// skip .By
if (nextOfOn is ByChainer)
{
nextOfOn = nextOfOn.Next;
}
// inject .On
var on = ((IOn)prevOfOn).On(expression);
on.SetNext(nextOfOn);
}
private Expression NonMappedByJoin(JoinChainer source, ByArgument arg)
{
_GetTargetByAlias(source, arg.Alias, false);
return(_GetNonMappedExpression(arg, source.Alias.Name));
}
