public override void Translate(
MethodCallExpression m, TranslationState state, UniqueNameGenerator nameGenerator)
{
// there may not be a preidcate in any method call
IDbObject condition = null;
if (m.GetArguments().Any())
{
condition = state.ResultStack.Pop();
}
var childSelect = (IDbSelect)state.ResultStack.Pop();
var dbSelect = (IDbSelect)state.ResultStack.Peek();
childSelect.Where = condition.ToBinary(_dbFactory);
var dbJoin = dbSelect.Joins.Single(j => ReferenceEquals(j.To.Referee, childSelect));
IDbBinary whereClause = null;
// ReSharper disable once LoopCanBeConvertedToQuery
foreach (var joinKey in dbJoin.Condition.GetOperands().OfType <IDbColumn>().Where(c => ReferenceEquals(c.Ref, dbJoin.To)))
{
var pkColumn = _dbFactory.BuildColumn(dbJoin.To, joinKey.Name, joinKey.ValType.DotNetType, joinKey.Alias);
var binary = _dbFactory.BuildBinary(pkColumn, DbOperator.IsNot, _dbFactory.BuildConstant(null));
whereClause = whereClause.UpdateBinary(binary, _dbFactory);
}
state.ResultStack.Push(whereClause);
}
protected static IDbSelectable GetAggregationTarget(MethodCallExpression m, TranslationState state)
{
if (!m.GetArguments().Any())
{
return(null);
}
var dbObj = state.ResultStack.Pop();
return((IDbSelectable)dbObj);
}
private IDbObject BuildCondition(MethodCallExpression m, TranslationState state)
{
var countOne = _dbFactory.BuildConstant(1);
if (!m.GetArguments().Any())
{
return(countOne);
}
var dbElement = state.ResultStack.Pop();
var dbBinary = dbElement.ToBinary(_dbFactory);
var tuple = Tuple.Create <IDbBinary, IDbObject>(dbBinary, countOne);
return(_dbFactory.BuildCondition(new [] { tuple }, _dbFactory.BuildConstant(null)));
}
protected override Expression VisitMethodCall(MethodCallExpression m)
{
var caller = m.GetCaller();
var args = m.GetArguments();
Visit(caller);
// remove unneed DbReference from stack, this is a side effect of translation of the caller
// we need to translate the caller to have the required select on the stack
// but we dont neeed other thing that come with it, such as the DbReference
while (_state.ResultStack.Count > 0 && _state.ResultStack.Peek() is DbReference)
{
_state.ResultStack.Pop();
}
VistMethodArguments(args);
if (!_plugIns.TranslateMethodCall(m, _state, _nameGenerator))
{
throw new NotSupportedException();
}
return(m);
}
