protected virtual Expression BuildExecuteBatch(DbBatchExpression batch)
{
var operation = this.Parameterize(batch.Operation.Body);
var commandText = this.linguist.Format(operation);
var namedValues = DbNamedValueGatherer.Gather(operation);
var command = new QueryCommand(commandText, namedValues.Select(v => new QueryParameter(v.Name, v.Type, v.QueryType)));
var values = namedValues.Select(v => Expression.Convert(this.Visit(v.Value), typeof(object))).ToArray() as Expression[];
var paramSets = Expression.Call
(
typeof(Enumerable), nameof(Enumerable.Select), new Type[] { batch.Operation.Parameters[1].Type, typeof(object[]) },
batch.Input,
Expression.Lambda(Expression.NewArrayInit(typeof(object), values), new[] { batch.Operation.Parameters[1] })
);
var plan = null as Expression;
var projection = ProjectionFinder.FindProjection(operation);
if (projection != null)
{
var saveScope = this.scope;
var reader = Expression.Parameter(typeof(FieldReader), "r" + nReaders++);
this.scope = new Scope(this.scope, reader, projection.Select.Alias, projection.Select.Columns);
var projector = Expression.Lambda(this.Visit(projection.Projector), reader);
this.scope = saveScope;
var entity = EntityFinder.Find(projection.Projector);
command = new QueryCommand(command.CommandText, command.Parameters);
plan = Expression.Call
(
this.executor, nameof(QueryExecutor.ExecuteBatch), new Type[] { projector.Body.Type },
Expression.Constant(command),
paramSets,
projector,
Expression.Constant(entity, typeof(MappingEntity)),
batch.BatchSize,
batch.Stream
);
}
else
{
plan = Expression.Call
(
this.executor, nameof(QueryExecutor.ExecuteBatch), null,
Expression.Constant(command),
paramSets,
batch.BatchSize,
batch.Stream
);
}
return(plan);
}
public static ReadOnlyCollection <DbNamedValueExpression> Gather(Expression expr)
{
var gatherer = new DbNamedValueGatherer();
if (gatherer != null)
{
gatherer.Visit(expr);
}
return(gatherer.namedValues.ToList().AsReadOnly());
}
private Expression ExecuteProjection(DbProjectionExpression projection, bool okayToDefer, bool isTopLevel)
{
projection = this.Parameterize(projection) as DbProjectionExpression;
if (this.scope != null)
{
projection = OuterParameterizer.Parameterize(this.scope.Alias, projection) as DbProjectionExpression;
}
var commandText = this.linguist.Format(projection.Select);
var namedValues = DbNamedValueGatherer.Gather(projection.Select);
var command = new QueryCommand(commandText, namedValues.Select(v => new QueryParameter(v.Name, v.Type, v.QueryType)));
var values = namedValues.Select(v => Expression.Convert(this.Visit(v.Value), typeof(object))).ToArray() as Expression[];
return(this.ExecuteProjection(projection, okayToDefer, command, values, isTopLevel));
}
protected virtual Expression BuildExecuteCommand(DbCommandExpression command)
{
var expression = this.Parameterize(command);
var commandText = this.linguist.Format(expression);
var namedValues = DbNamedValueGatherer.Gather(expression);
var qc = new QueryCommand(commandText, namedValues.Select(v => new QueryParameter(v.Name, v.Type, v.QueryType)));
var values = namedValues.Select(v => Expression.Convert(this.Visit(v.Value), typeof(object))).ToArray() as Expression[];
var projection = ProjectionFinder.FindProjection(expression);
if (projection != null)
{
return(this.ExecuteProjection(projection, false, qc, values, isTopLevel: true));
}
var plan = Expression.Call
(
this.executor, nameof(QueryExecutor.ExecuteCommand), null,
Expression.Constant(qc),
Expression.NewArrayInit(typeof(object), values)
);
return(plan);
}
