// Note: command expected to be analyzed already
public SqlStatement Translate(LinqCommand command)
{
// pre-process; special commands do not produce lambda when command is created - only SqlCacheKey so that SQL
// is looked up in cache and we do not need anything else; building actual query lambda is encoded in setup Action,
// which we invoke here;
// also dynamic linq queries postpone rewrite (changing locals to parameters) until late time
switch (command)
{
case SpecialLinqCommand specCmd:
specCmd.SetupAction?.Invoke(specCmd);
break;
case DynamicLinqCommand dynCmd:
if (command.Lambda == null)
{
LinqCommandRewriter.RewriteToLambda(dynCmd);
}
break;
} //switch
try {
switch (command.Operation)
{
case LinqOperation.Select:
return(TranslateSelect(command));
case LinqOperation.Update:
case LinqOperation.Delete:
case LinqOperation.Insert:
default:
return(TranslateNonQuery((DynamicLinqCommand)command));
} //switch
} catch (LinqTranslationException) {
throw; // if it is already Linq translation exception, pass it up.
} catch (Exception ex) {
var message = "Linq to SQL translation failed, invalid expression: " + ex.Message;
throw new LinqTranslationException(message, command, ex);
}
}
public static void RewriteToLambda(DynamicLinqCommand command)
{
var rewriter = new LinqCommandRewriter();
rewriter.RewriteCommand(command);
}
