protected override Expression BuildExecuteCommand(CommandExpression command)
{
// parameterize query
var expression = this.Parameterize(command);
string commandText = this.Linguist.Format(expression);
ReadOnlyCollection<NamedValueExpression> namedValues = NamedValueGatherer.Gather(expression);
QueryCommand qc = new QueryCommand(commandText, namedValues.Select(v => new QueryParameter(v.Name, v.Type, v.QueryType)), false);
Expression[] values = namedValues.Select(v => Expression.Convert(this.Visit(v.Value), typeof(object))).ToArray();
if (command is OInsertCommandExpression)
{
// insert will directly return a populated instance without the need for a BlockCommandExpression
// to execute first an INSERT followed by a SELECT - so here we utilize the same Execute method
// as a projection in order to map the returned values into an entity instance in a single call
return ExecuteInsert((OInsertCommandExpression)command, qc, values);
}
else if (command is OUpdateCommandExpression)
{
// update will directly return a populated instance without the need for a BlockCommandExpression
// to execute first an INSERT followed by a SELECT - so here we utilize the same Execute method
// as a projection in order to map the returned values into an entity instance in a single call
return ExecuteUpdate((OUpdateCommandExpression)command, qc, values);
}
else
{
ProjectionExpression projection = ProjectionFinder.FindProjection(expression);
if (projection != null)
{
return this.ExecuteProjection(projection, qc, values);
}
}
Expression plan = Expression.Call(this.Executor, "ExecuteCommand", null,
Expression.Constant(qc),
Expression.NewArrayInit(typeof(object), values)
);
return plan;
}
protected virtual Expression VisitCommand(CommandExpression command)
{
switch ((DbExpressionType)command.NodeType)
{
case DbExpressionType.Insert:
return this.VisitInsert((InsertCommandExpression)command);
case DbExpressionType.Update:
return this.VisitUpdate((UpdateCommandExpression)command);
case DbExpressionType.Delete:
return this.VisitDelete((DeleteCommandExpression)command);
case DbExpressionType.If:
return this.VisitIf((IfCommandExpression)command);
case DbExpressionType.Block:
return this.VisitBlock((BlockCommandExpression)command);
case DbExpressionType.Declaration:
return this.VisitDeclaration((DeclarationCommand)command);
default:
return this.VisitUnknown(command);
}
}
protected override Expression VisitCommand(CommandExpression command)
{
this.isTopLevel = true;
return base.VisitCommand(command);
}
protected override Expression VisitCommand(CommandExpression command)
{
return base.VisitCommand(command);
}
protected override bool IsMultipleCommands(CommandExpression command)
{
return base.IsMultipleCommands(command);
}
protected virtual Expression VisitCommand(CommandExpression command)
{
this.Write(this.FormatQuery(command));
return command;
}
