Keep guessed parameter type in hql

src/NHibernate.Test/Async/Linq/LinqQuerySamples.cs

@@ -1385,5 +1385,15 @@ public void ReplaceFunctionWithNullArgumentAsync()
 				}, Throws.Nothing, "Expected REPLACE(FirstName, LastName, NULL) to be supported");
 			Assert.That(results, Is.Not.Null);
 		}
+
+		[Test(Description = "GH-2860")]
+		public async Task StringFormatWithTrimAsync()
+		{
+			var q =
+				from e in db.Employees
+				select new {Name = $"{e.FirstName} {e.LastName}".Trim(), Phone = e.Address.PhoneNumber};
+			var items = await (q.ToListAsync());
+			Assert.AreEqual(9, items.Count);
+		}
 	}
 }

src/NHibernate.Test/Linq/LinqQuerySamples.cs

@@ -1970,6 +1970,16 @@ public void ReplaceFunctionWithNullArgument()
 				}, Throws.Nothing, "Expected REPLACE(FirstName, LastName, NULL) to be supported");
 			Assert.That(results, Is.Not.Null);
 		}
+
+		[Test(Description = "GH-2860")]
+		public void StringFormatWithTrim()
+		{
+			var q =
+				from e in db.Employees
+				select new {Name = $"{e.FirstName} {e.LastName}".Trim(), Phone = e.Address.PhoneNumber};
+			var items = q.ToList();
+			Assert.AreEqual(9, items.Count);
+		}
 	}
 
 	public class ParentChildBatch<T, TKey, TSub>

src/NHibernate/Hql/Ast/ANTLR/HqlSqlWalker.cs

@@ -1070,7 +1070,10 @@ IASTNode GenerateNamedParameter(IASTNode delimiterNode, IASTNode nameNode)
 			{
 				// Add the parameter type information so that we are able to calculate functions return types
 				// when the parameter is used as an argument.
-				parameter.ExpectedType = namedParameter.Type;
+				if (namedParameter.IsGuessedType)
+					parameter.GuessedType = namedParameter.Type;
+				else
+					parameter.ExpectedType = namedParameter.Type;
 			}
 
 			_parameters.Add(paramSpec);

src/NHibernate/Hql/Ast/ANTLR/Tree/ParameterNode.cs

@@ -49,6 +49,8 @@ public IType ExpectedType
 			}
 		}
 
+		internal IType GuessedType { get; set; }
+
 		public override SqlString RenderText(ISessionFactoryImplementor sessionFactory)
 		{
 			int count;

src/NHibernate/Hql/Ast/ANTLR/Tree/SelectClause.cs

@@ -153,9 +153,14 @@ public void InitializeExplicitSelectClause(FromClause fromClause)
 				else
 				{
 					IType type = expr.DataType;
-					if (type == null && !(expr is ParameterNode))
+					if (type == null)
 					{
-						throw new QueryException("No data type for node: " + expr.GetType().Name + " " + new ASTPrinter().ShowAsString((IASTNode)expr, ""));
+						if (expr is ParameterNode param)
+						{
+							type = param.GuessedType;
+						}
+						else
+							throw new QueryException("No data type for node: " + expr.GetType().Name + " " + new ASTPrinter().ShowAsString((IASTNode)expr, ""));
 					}
 					//sqlResultTypeList.add( type );
 

src/NHibernate/Linq/Visitors/ParameterTypeLocator.cs

@@ -93,7 +93,8 @@ internal static void SetParameterTypes(
 					continue;
 				}
 
-				namedParameter.Type = GetParameterType(sessionFactory, constantExpressions, visitor, namedParameter);
+				namedParameter.Type = GetParameterType(sessionFactory, constantExpressions, visitor, namedParameter, out var tryProcessInHql);
+				namedParameter.IsGuessedType = tryProcessInHql;
 			}
 		}
 
@@ -145,8 +146,10 @@ private static IType GetParameterType(
 			ISessionFactoryImplementor sessionFactory,
 			HashSet<ConstantExpression> constantExpressions,
 			ConstantTypeLocatorVisitor visitor,
-			NamedParameter namedParameter)
+			NamedParameter namedParameter,
+			out bool tryProcessInHql)
 		{
+			tryProcessInHql = false;
 			// All constant expressions have the same type/value
 			var constantExpression = constantExpressions.First();
 			var constantType = constantExpression.Type.UnwrapIfNullable();
@@ -158,7 +161,7 @@ private static IType GetParameterType(
 
 			if (visitor.NotGuessableConstants.Contains(constantExpression) && constantExpression.Value != null)
 			{
-				return null;
+				tryProcessInHql = true;
 			}
 
 			// No related MemberExpressions was found, guess the type by value or its type when null.

src/NHibernate/Param/NamedParameter.cs

@@ -20,6 +20,7 @@ internal NamedParameter(string name, object value, IType type, bool isCollection
 		public string Name { get; private set; }
 		public object Value { get; internal set; }
 		public IType Type { get; internal set; }
+		internal bool IsGuessedType { get; set; }
 
 		public virtual bool IsCollection { get; }