protected override Expression VisitCommand(DbCommandExpression command)
{
if (this.linguist.Language.AllowsMultipleCommands || !IsMultipleCommands(command))
{
return(this.BuildExecuteCommand(command));
}
return(base.VisitCommand(command));
}
protected virtual bool IsMultipleCommands(DbCommandExpression command)
{
if (command == null)
{
return(false);
}
switch ((DbExpressionType)command.NodeType)
{
case DbExpressionType.Insert:
case DbExpressionType.Delete:
case DbExpressionType.Update: return(false);
default: return(true);
}
}
protected virtual Expression VisitCommand(DbCommandExpression command)
{
switch ((DbExpressionType)command.NodeType)
{
case DbExpressionType.Insert: return(this.VisitInsert(command as DbInsertCommand));
case DbExpressionType.Update: return(this.VisitUpdate(command as DbUpdateCommand));
case DbExpressionType.Delete: return(this.VisitDelete(command as DbDeleteCommand));
case DbExpressionType.If: return(this.VisitIf(command as DbIFCommand));
case DbExpressionType.Block: return(this.VisitBlock(command as DbBlockCommand));
case DbExpressionType.Declaration: return(this.VisitDeclaration(command as DbDeclarationCommand));
default:
{
return(this.VisitUnknown(command));
}
}
}
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);
}
protected override Expression VisitCommand(DbCommandExpression command)
{
this.isTopLevel = true;
return(base.VisitCommand(command));
}
protected virtual Expression VisitCommand(DbCommandExpression command)
{
this.Write(this.FormatQuery(command)); return(command);
}