protected override Expression VisitSimpleDbQuery(QueryExpression qex)
{
if (qex.Source is ConstantExpression)
{
var source = (ConstantExpression)qex.Source;
if (source.Value is ISimpleDbItemCollection)
{
return SimpleDbExpression.Query(
qex.Select,
SimpleDbExpression.Domain(((ISimpleDbItemCollection)source.Value).Domain),
qex.Where,
qex.OrderBy,
qex.Limit,
qex.UseConsistency);
}
else
{
throw new NotSupportedException(
string.Format("Cannot determine data source from '{0}'", source.Value.GetType())
);
}
}
else
{
Expression source = base.Visit(qex.Source);
return SimpleDbExpression.Query(
qex.Select,
source,
qex.Where,
qex.OrderBy,
qex.Limit,
qex.UseConsistency);
}
}
protected override Expression VisitSimpleDbQuery(QueryExpression qex)
{
//if select list is explicit, must ensure attributes referenced in OrderBy are included
if (qex.Select.Attributes.Count() > 0 && qex.OrderBy.Count() > 0)
{
return SimpleDbExpression.Query(
SimpleDbExpression.Select(
qex.Select.Attributes.Union(qex.OrderBy.Select(ob => ob.Attribute))
),
qex.Source,
qex.Where,
qex.OrderBy,
qex.Limit,
qex.UseConsistency);
}
return base.VisitSimpleDbQuery(qex);
}
public static ProjectionExpression Project(QueryExpression query, Expression projector)
{
return new ProjectionExpression(query, projector);
}
protected override Expression VisitSimpleDbQuery(QueryExpression qex)
{
return this.AggregateAndReduce(qex);
}
protected override Expression VisitSimpleDbQuery(QueryExpression ssex)
{
if (ssex.Where != null)
{
if (_aggregatedWhere == null)
{
_aggregatedWhere = ssex.Where;
}
else
{
_aggregatedWhere = Expression.AndAlso(_aggregatedWhere, ssex.Where);
}
}
if (ssex.OrderBy != null)
{
_aggregatedOrderBy.InsertRange(0, ssex.OrderBy);
}
if(ssex.Limit != null)
{
_limit = ssex.Limit;
}
Visit(ssex.Select);
_source = ssex.Source;
if (_source is QueryExpression)
{
Visit(ssex.Source);
}
if (ssex.UseConsistency == true)
{
_useConsistency = true;
}
return ssex;
}
protected virtual Expression VisitSimpleDbQuery(QueryExpression qex)
{
return qex;
}
public ProjectionExpression(QueryExpression source, Expression projector, Expression originalExpression)
{
this._source = source;
this._projector = projector;
this._originalExpression = originalExpression;
}
public ProjectionExpression(QueryExpression source, Expression projector)
: this(source, projector, null)
{
}
internal QueryCommand(QueryExpression query)
{
_query = query;
_queryText = QueryWriter.Write(query);
}
