whereparser.cs

NHibernate NET开发者所需的

		public void End(QueryTranslator q)
		{
			if (expectingPathContinuation)
			{
				expectingPathContinuation = false;
				PathExpressionParser.CollectionElement element = pathExpressionParser.LastCollectionElement();
				if (element.ElementColumns.Length != 1)
				{
					throw new QueryException("path expression ended in composite collection element");
				}
				AppendToken(q, element.ElementColumns[0]);
				AddToCurrentJoin(element);
			}
			Token(StringHelper.ClosedParen, q);
		}

		private void CloseExpression(QueryTranslator q, string lcToken)
		{
			bool lastBoolTest = booleanTests[booleanTests.Count - 1];
			booleanTests.RemoveAt(booleanTests.Count - 1);
			if (lastBoolTest)
			{
				//it was a boolean expression
				if (booleanTests.Count > 0)
				{
					// the next one up must also be
					booleanTests[booleanTests.Count - 1] = true;
				}

				// Add any joins
				SqlStringBuilder lastJoin = joins[joins.Count - 1];
				joins.RemoveAt(joins.Count - 1);
				AppendToken(q, lastJoin.ToSqlString());
			}
			else
			{
				//unaryCounts.removeLast(); //check that its zero? (As an assertion)
				SqlStringBuilder join = joins[joins.Count - 1];
				joins.RemoveAt(joins.Count - 1);
				joins[joins.Count - 1].Add(join.ToSqlString());
			}

			bool lastNots = nots[nots.Count - 1];
			nots.RemoveAt(nots.Count - 1);
			if (lastNots)
			{
				negated = !negated;
			}

			if (!StringHelper.ClosedParen.Equals(lcToken))
			{
				AppendToken(q, StringHelper.ClosedParen);
			}
		}

		private void OpenExpression(QueryTranslator q, string lcToken)
		{
			nots.Add(false);
			booleanTests.Add(false);
			joins.Add(new SqlStringBuilder());
			if (!StringHelper.OpenParen.Equals(lcToken))
			{
				AppendToken(q, StringHelper.OpenParen);
			}
		}

		private void Preprocess(string token, QueryTranslator q)
		{
			// ugly hack for cases like "foo.bar.collection.elements" 
			// (multi-part path expression ending in elements or indices) 
			string[] tokens = StringHelper.Split(".", token, true);
			if (tokens.Length > 5 &&
			    ("elements".Equals(tokens[tokens.Length - 1]) || "indices".Equals(tokens[tokens.Length - 1])))
			{
				pathExpressionParser.Start(q);
				for (int i = 0; i < tokens.Length - 3; i++)
				{
					pathExpressionParser.Token(tokens[i], q);
				}
				pathExpressionParser.Token(null, q);
				pathExpressionParser.End(q);
				AddJoin(pathExpressionParser.WhereJoin, q);
				pathExpressionParser.IgnoreInitialJoin();
			}
		}

		private void DoPathExpression(string token, QueryTranslator q)
		{
			Preprocess(token, q);

			StringTokenizer tokens = new StringTokenizer(token, ".", true);
			pathExpressionParser.Start(q);
			foreach (string tok in tokens)
			{
				pathExpressionParser.Token(tok, q);
			}
			pathExpressionParser.End(q);

			if (pathExpressionParser.IsCollectionValued)
			{
				OpenExpression(q, string.Empty);
				AppendToken(q, pathExpressionParser.GetCollectionSubquery(q.EnabledFilters));
				CloseExpression(q, string.Empty);
				// this is ugly here, but needed because its a subquery
				q.AddQuerySpaces(q.GetCollectionPersister(pathExpressionParser.CollectionRole).CollectionSpaces);
			}
			else
			{
				if (pathExpressionParser.IsExpectingCollectionIndex)
				{
					expectingIndex++;
				}
				else
				{
					AddJoin(pathExpressionParser.WhereJoin, q);
					AppendToken(q, pathExpressionParser.WhereColumn);
				}
			}
		}

		private void AddJoin(JoinSequence joinSequence, QueryTranslator q)
		{
			q.AddFromJoinOnly(pathExpressionParser.Name, joinSequence);
			try
			{
				AddToCurrentJoin(joinSequence.ToJoinFragment(q.EnabledFilters, true).ToWhereFragmentString);
			}
			catch (MappingException me)
			{
				throw new QueryException(me);
			}
		}

		private void DoToken(string token, QueryTranslator q)
		{
			if (q.IsName(StringHelper.Root(token))) //path expression
			{
				DoPathExpression(q.Unalias(token), q);
			}
			else if (token.StartsWith(ParserHelper.HqlVariablePrefix)) //named query parameter
			{
				q.AddNamedParameter(token.Substring(1));
				// this is only a temporary parameter to help with the parsing of hql - 
				// when the type becomes known then this will be converted to its real
				// parameter type.
				AppendToken(q, SqlString.Parameter);
			}
			else if (token.Equals(StringHelper.SqlParameter))
			{
				//if the token is a "?" then we have a Parameter so convert it to a SqlCommand.Parameter
				// instead of appending a "?" to the WhereTokens
				AppendToken(q, SqlString.Parameter);
			}
			else
			{
				IQueryable persister = q.GetPersisterUsingImports(token);
				if (persister != null) // the name of a class
				{
					string discrim = persister.DiscriminatorSQLValue;
					if (InFragment.Null == discrim || InFragment.NotNull == discrim)
					{
						throw new QueryException("subclass test not allowed for null or not null discriminator");
					}
					AppendToken(q, discrim);
				}
				else
				{
					object constant;
					string fieldName = null;
					System.Type importedType = null;

					int indexOfDot = token.IndexOf(StringHelper.Dot);
					// don't even bother to do the lookups if the indexOfDot is not 
					// greater than -1.  This will save all the string modifications.

					// This allows us to resolve to the full type before obtaining the value e.g. FooStatus.OFF -> NHibernate.Model.FooStatus.OFF
					if (indexOfDot > -1)
					{
						fieldName = StringHelper.Unqualify(token);
						string typeName = StringHelper.Qualifier(token);
						importedType = SessionFactoryHelper.GetImportedClass(q.Factory, typeName);
					}

					if (indexOfDot > -1 && importedType != null &&
							(constant = ReflectHelper.GetConstantValue(importedType, fieldName)) != null)
					{
						// need to get the NHibernate Type so we can convert the Enum or field from 
						// a class into it's string representation for hql.
						IType type;
						try
						{
							type = TypeFactory.HeuristicType(constant.GetType().AssemblyQualifiedName);
						}
						catch (MappingException me)
						{
							throw new QueryException(me);
						}

						if (type == null)
						{
							throw new QueryException(string.Format("Could not determin the type of: {0}", token));
						}

						try
						{
							AppendToken(q, ((ILiteralType)type).ObjectToSQLString(constant, q.Factory.Dialect));
						}
						catch (Exception e)
						{
							throw new QueryException("Could not format constant value to SQL literal: " + token, e);
						}
					}
					else
					{
						//anything else
						string negatedToken = null;
						if (negated)
							negations.TryGetValue(token.ToLowerInvariant(), out negatedToken);
						if (negatedToken != null && (!betweenSpecialCase || !"or".Equals(negatedToken)))
						{
							AppendToken(q, negatedToken);
						}
						else
						{
							AppendToken(q, token);
						}
					}
				}
			}
		}

		private void AddToCurrentJoin(SqlString sql)
		{
			joins[joins.Count - 1].Add(sql);
		}

		private void AddToCurrentJoin(PathExpressionParser.CollectionElement ce)
		{
			try
			{
				AddToCurrentJoin(ce.JoinSequence.ToJoinFragment().ToWhereFragmentString + ce.IndexValue.ToSqlString());
			}
			catch (MappingException me)
			{
				throw new QueryException(me);
			}
		}

		private void SpecialCasesBefore(string lcToken)
		{
			if ("between".Equals(lcToken) || "not between".Equals(lcToken))
			{
				betweenSpecialCase = true;
			}
		}

		private void SpecialCasesAfter(string lcToken)
		{
			if (betweenSpecialCase && "and".Equals(lcToken))
			{
				betweenSpecialCase = false;
			}
		}

		protected virtual void AppendToken(QueryTranslator q, string token)
		{
			if (expectingIndex > 0)
			{
				pathExpressionParser.SetLastCollectionElementIndexValue(new SqlString(token));
			}
			else
			{
				// a String.Empty can get passed in here.  If that occurs
				// then don't create a new SqlString for it - just ignore
				// it since it adds nothing to the sql being generated.
				if (token != null && token.Length > 0)
				{
					q.AppendWhereToken(new SqlString(token));
				}
			}
		}

		protected virtual void AppendToken(QueryTranslator q, SqlString token)
		{
			if (expectingIndex > 0)
			{
				pathExpressionParser.SetLastCollectionElementIndexValue(token);
			}
			else
			{
				q.AppendWhereToken(token);
			}
		}

		private bool ContinuePathExpression(string token, QueryTranslator q)
		{
			expectingPathContinuation = false;

			PathExpressionParser.CollectionElement element = pathExpressionParser.LastCollectionElement();

			if (token.StartsWith("."))
			{
				// the path expression continues after a ]

				DoPathExpression(GetElementName(element, q) + token, q); // careful with this!

				AddToCurrentJoin(element);
				return true; //NOTE: EARLY EXIT!
			}
			else
			{
				// the path expression ends at the ]
				if (element.ElementColumns.Length != 1)
				{
					throw new QueryException("path expression ended in composite collection element");
				}
				AppendToken(q, element.ElementColumns[0]);
				AddToCurrentJoin(element);
				return false;
			}
		}
	}
}