protected virtual UpdateCommandExpression UpdateUpdate(OUpdateCommandExpression update, IdentifiableExpression table, Expression where,
IEnumerable<FieldAssignment> assignments, ProjectionExpression projection)
{
if (table != update.Identifiable || where != update.Where || assignments != update.Assignments || projection.Projector != update.Projection.Projector)
{
return new OUpdateCommandExpression(table, where, assignments, projection.Projector);
}
return update;
}
private Expression ExecuteUpdate(OUpdateCommandExpression update, QueryCommand command, Expression[] values)
{
var reader = Expression.Parameter(typeof(FieldReader), "r" + nReaders++);
var saveScope = this.scope;
var projection = this.Linguist.Translator.Mapper.GetQueryExpression(new OMappingEntity(update.Projection.Projector.Type, _repoType));
var fields = new OFieldFinder().Find(update.Projection.Projector).Select(fe => new FieldDeclaration(fe.Name, fe, fe.QueryType)).ToArray();
var alias = ((FieldExpression)fields[0].Expression).Alias;
this.scope = new BuilderScope(
this.scope,
reader,
alias,
fields)
{
UseOrdinalMapping = false // we can't guarantee the order that properties will be returned, so we need to read by name
};
//var projector = Expression.Lambda(this.Visit(update.Projection.Projector), reader);
var projector = RedirectProjector(update.Projection.Projector, reader, false);
this.scope = saveScope;
var entity = EntityFinder.Find(update.Projection.Projector);
// call low-level execute directly on supplied DbQueryProvider
Expression result = Expression.Call(this.Executor, "Execute", new Type[] { update.Identifiable.Entity.EntityType },
Expression.Constant(command),
projector,
Expression.Constant(entity, typeof(MappingEntity)),
Expression.NewArrayInit(typeof(object), values)
);
if (update.Projection.Aggregator != null)
{
// apply aggregator
result = DbExpressionReplacer.Replace(update.Projection.Aggregator.Body, update.Projection.Aggregator.Parameters[0], result);
}
return result;
}
