AbstractQueryImpl.cs

using System;
using System.Collections;
using System.Collections.Generic;
using NHibernate.Engine;
using NHibernate.Engine.Query;
using NHibernate.Hql;
using NHibernate.Multi;
using NHibernate.Proxy;
using NHibernate.Transform;
using NHibernate.Type;
using NHibernate.Util;
using System.Linq;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;

namespace NHibernate.Impl
{
	/// <summary>
	/// Abstract implementation of the IQuery interface.
	/// </summary>
	public abstract partial class AbstractQueryImpl : IQuery
	{
		private readonly string queryString;
		protected readonly ISessionImplementor session;
		protected internal ParameterMetadata parameterMetadata;

		private readonly RowSelection selection;
		private readonly List<object> values = new List<object>(4);
		private readonly List<IType> types = new List<IType>(4);
		private readonly Dictionary<string, TypedValue> namedParameters = new Dictionary<string, TypedValue>(4);
		protected readonly Dictionary<string, TypedValue> namedParameterLists = new Dictionary<string, TypedValue>(4);
		private bool cacheable;
		private string cacheRegion;
		private bool? readOnly;
		private static readonly object UNSET_PARAMETER = new object();
		private static readonly IType UNSET_TYPE = null;
		private object optionalId;
		private object optionalObject;
		private string optionalEntityName;
		private FlushMode flushMode = FlushMode.Unspecified;
		private FlushMode sessionFlushMode = FlushMode.Unspecified;
		private object collectionKey;
		private IResultTransformer resultTransformer;
		private bool shouldIgnoredUnknownNamedParameters;
		private CacheMode? cacheMode;
		private CacheMode? sessionCacheMode;
		private string comment;

		protected AbstractQueryImpl(string queryString, FlushMode flushMode, ISessionImplementor session,
			ParameterMetadata parameterMetadata)
		{
			this.session = session;
			this.queryString = queryString;
			selection = new RowSelection();
			this.flushMode = flushMode;
			cacheMode = null;
			this.parameterMetadata = parameterMetadata;
		}

		public bool Cacheable
		{
			get { return cacheable; }
		}

		public string CacheRegion
		{
			get { return cacheRegion; }
		}

		public bool HasNamedParameters
		{
			get { return parameterMetadata.NamedParameterNames.Count > 0; }
		}

		protected internal virtual void VerifyParameters()
		{
			VerifyParameters(false);
		}

		/// <summary>
		/// Perform parameters validation. Flatten them if needed. Used prior to executing the encapsulated query.
		/// </summary>
		/// <param name="reserveFirstParameter">
		/// If true, the first positional parameter will not be verified since
		/// its needed for e.g. callable statements returning an out parameter.
		/// </param>
		protected internal virtual void VerifyParameters(bool reserveFirstParameter)
		{
			if (parameterMetadata.NamedParameterNames.Count != namedParameters.Count + namedParameterLists.Count)
			{
				var missingParams = new HashSet<string>(parameterMetadata.NamedParameterNames);
				missingParams.ExceptWith(namedParameterLists.Keys);
				missingParams.ExceptWith(namedParameters.Keys);
				throw new QueryException("Not all named parameters have been set: " + CollectionPrinter.ToString(missingParams), QueryString);
			}

			var positionalValueSpan = 0;
			// Values and Types may be overriden to yield refined parameters, check them
			// instead of the fields.
			var values = Values;
			var types = Types;
			for (var i = 0; i < values.Count; i++)
			{
				var type = types[i];
				if (values[i] == UNSET_PARAMETER || type == UNSET_TYPE)
				{
					if (reserveFirstParameter && i == 0)
					{
						continue;
					}
					else
					{
						throw new QueryException("Unset positional parameter at position: " + i, QueryString);
					}
				}
				positionalValueSpan++;
			}

			if (parameterMetadata.OrdinalParameterCount != positionalValueSpan)
			{
				if (reserveFirstParameter && parameterMetadata.OrdinalParameterCount - 1 != positionalValueSpan)
				{
					throw new QueryException(
						"Expected positional parameter count: " + (parameterMetadata.OrdinalParameterCount - 1) + ", actual parameters: "
						+ CollectionPrinter.ToString(values), QueryString);
				}
				else if (!reserveFirstParameter)
				{
					throw new QueryException(
						"Expected positional parameter count: " + parameterMetadata.OrdinalParameterCount + ", actual parameters: "
						+ CollectionPrinter.ToString(values), QueryString);
				}
			}
		}

		protected internal virtual IType DetermineType(int paramPosition, object paramValue, IType defaultType)
		{
			IType type = parameterMetadata.GetOrdinalParameterExpectedType(paramPosition + 1) ?? defaultType;
			return type;
		}

		protected internal virtual IType DetermineType(int paramPosition, object paramValue)
		{
			IType type = parameterMetadata.GetOrdinalParameterExpectedType(paramPosition + 1) ??
			             ParameterHelper.GuessType(paramValue, session.Factory);
			return type;
		}

		protected internal virtual IType DetermineType(string paramName, object paramValue, IType defaultType)
		{
			IType type = parameterMetadata.GetNamedParameterExpectedType(paramName) ?? defaultType;
			return type;
		}

		protected internal virtual IType DetermineType(string paramName, object paramValue)
		{
			IType type = parameterMetadata.GetNamedParameterExpectedType(paramName) ??
			             ParameterHelper.GuessType(paramValue, session.Factory);
			return type;
		}

		protected internal virtual IType DetermineType(string paramName, System.Type clazz)
		{
			IType type = parameterMetadata.GetNamedParameterExpectedType(paramName) ??
			             ParameterHelper.GuessType(clazz, session.Factory);
			return type;
		}

		/// <summary>
		/// Warning: adds new parameters to the argument by side-effect, as well as mutating the query string!
		/// </summary>
		protected internal virtual string ExpandParameterLists(IDictionary<string, TypedValue> namedParamsCopy)
		{
			string query = queryString;
			foreach (var me in namedParameterLists)
				query = ExpandParameterList(query, me.Key, me.Value, namedParamsCopy);

			return query;
		}

		/// <summary>
		/// Warning: adds new parameters to the argument by side-effect, as well as mutating the query string!
		/// </summary>
		private string ExpandParameterList(string query, string name, TypedValue typedList, IDictionary<string, TypedValue> namedParamsCopy)
		{
			var vals = (IEnumerable) typedList.Value;
			var type = typedList.Type;

			var typedValues = (from object value in vals
							   select new TypedValue(type, value, false))
				.ToList();

			if (typedValues.Count == 1)
			{
				namedParamsCopy[name] = typedValues[0];
				return query;
			}
			
			var isJpaPositionalParam = parameterMetadata.GetNamedParameterDescriptor(name).JpaStyle;
			var aliases = new string[typedValues.Count];
			for (var index = 0; index < typedValues.Count; index++)
			{
				var value = typedValues[index];
				var alias =  (isJpaPositionalParam ? 'x' + name : name + StringHelper.Underscore) + index + StringHelper.Underscore;
				namedParamsCopy[alias] = value;
				aliases[index] = ParserHelper.HqlVariablePrefix + alias;
			}

			var paramPrefix = isJpaPositionalParam ? StringHelper.SqlParameter : ParserHelper.HqlVariablePrefix;

			return Regex.Replace(
				query,
				Regex.Escape(paramPrefix + name) + @"\b",
				string.Join(StringHelper.CommaSpace, aliases));
		}

		#region Parameters

		public IQuery SetParameter(int position, object val, IType type)
		{
			CheckPositionalParameter(position);
			int size = values.Count;
			if (position < size)
			{
				values[position] = val;
				types[position] = type;
			}
			else
			{
				// prepend value and type list with null for any positions before the wanted position.
				for (int i = 0; i < position - size; i++)
				{
					values.Add(UNSET_PARAMETER);
					types.Add(UNSET_TYPE);
				}
				values.Add(val);
				types.Add(type);
			}
			return this;
		}

		public IQuery SetParameter(string name, object val, IType type)
		{
			return SetParameter(name, val, type, false);
		}

		//TODO 6.0: Add to IQuery interface
		public IQuery SetParameter(string name, object val, IType type, bool preferMetadataType)
		{
			if (CheckParameterIgnored(name))
				return this;

			if (type == null || preferMetadataType)
			{
				type = parameterMetadata.GetNamedParameterExpectedType(name) ?? type ?? ParameterHelper.GuessType(val, session.Factory);
			}

			namedParameters[name] = new TypedValue(type, val, false);
			return this;
		}

		private bool CheckParameterIgnored(string name)
		{
			if (parameterMetadata.NamedParameterNames.Contains(name))
				return false;

			if (shouldIgnoredUnknownNamedParameters) //just ignore it
				return true;

			throw new ArgumentException("Parameter " + name + " does not exist as a named parameter in [" + QueryString + "]");
		}

		public IQuery SetParameter<T>(int position, T val)
		{
			CheckPositionalParameter(position);

			return SetParameter(
				position,
				val,
				parameterMetadata.GetOrdinalParameterExpectedType(position + 1) ??
				ParameterHelper.GuessType(typeof(T), session.Factory));
		}

		private void CheckPositionalParameter(int position)
		{
			if (parameterMetadata.OrdinalParameterCount == 0)
			{
				throw new ArgumentException("No positional parameters in query: " + QueryString);
			}
			if (position < 0 || position > parameterMetadata.OrdinalParameterCount - 1)
			{
				throw new ArgumentException("Positional parameter does not exist: " + position + " in query: " + QueryString);
			}
		}

		public IQuery SetParameter<T>(string name, T val)
		{
			return SetParameter(
				name,
				val,
				parameterMetadata.GetNamedParameterExpectedType(name) ??
				ParameterHelper.GuessType(typeof(T), session.Factory));
		}

		public IQuery SetParameter(string name, object val)
		{
			return SetParameter(name, val, null, true);
		}

		public IQuery SetParameter(int position, object val)
		{
			if (val == null)
			{
				throw new ArgumentNullException("val",
																				"A type specific Set(position, val) should be called because the Type can not be guessed from a null value.");
			}
			else
			{
				SetParameter(position, val, DetermineType(position, val));
			}
			return this;
		}

		public IQuery SetAnsiString(int position, string val)
		{
			SetParameter(position, val, NHibernateUtil.AnsiString);
			return this;
		}

		public IQuery SetString(int position, string val)
		{
			SetParameter(position, val, NHibernateUtil.String);
			return this;
		}

		public IQuery SetCharacter(int position, char val)
		{
			SetParameter(position, val, NHibernateUtil.Character); // );
			return this;
		}

		public IQuery SetBoolean(int position, bool val)
		{
			SetParameter(position, val, NHibernateUtil.Boolean); // );
			return this;
		}

		public IQuery SetByte(int position, byte val)
		{
			SetParameter(position, val, NHibernateUtil.Byte);
			return this;
		}

		public IQuery SetInt16(int position, short val)
		{
			SetParameter(position, val, NHibernateUtil.Int16);
			return this;
		}

		public IQuery SetInt32(int position, int val)
		{
			SetParameter(position, val, NHibernateUtil.Int32);
			return this;
		}

		public IQuery SetInt64(int position, long val)
		{
			SetParameter(position, val, NHibernateUtil.Int64);
			return this;
		}

		public IQuery SetSingle(int position, float val)
		{
			SetParameter(position, val, NHibernateUtil.Single);
			return this;
		}

		public IQuery SetDouble(int position, double val)
		{
			SetParameter(position, val, NHibernateUtil.Double);
			return this;
		}

		public IQuery SetBinary(int position, byte[] val)
		{
			SetParameter(position, val, NHibernateUtil.Binary);
			return this;
		}

		public IQuery SetDateTimeOffset(string name, DateTimeOffset val)
		{
			SetParameter(name, val, NHibernateUtil.DateTimeOffset);
			return this;
		}

		public IQuery SetDecimal(int position, decimal val)
		{
			SetParameter(position, val, NHibernateUtil.Decimal);
			return this;
		}

		public IQuery SetDateTime(int position, DateTime val)
		{
			SetParameter(position, val, NHibernateUtil.DateTime);
			return this;
		}

		public IQuery SetDateTimeNoMs(int position, DateTime val)
		{
			SetParameter(position, val, NHibernateUtil.DateTimeNoMs);
			return this;
		}

		// Since v5.0
		[Obsolete("Use SetDateTime instead, it uses DateTime2 with dialects supporting it.")]
		public IQuery SetDateTime2(int position, DateTime val)
		{
			SetParameter(position, val, NHibernateUtil.DateTime2);
			return this;
		}

		public IQuery SetTime(int position, DateTime val)
		{
			SetParameter(position, val, NHibernateUtil.Time);
			return this;
		}

		// Since v5.0
		[Obsolete("Use SetDateTime instead.")]
		public IQuery SetTimestamp(int position, DateTime val)
		{
			SetParameter(position, val, NHibernateUtil.Timestamp);
			return this;
		}

		public IQuery SetEntity(int position, object val)
		{
			SetParameter(position, val, NHibernateUtil.Entity(NHibernateProxyHelper.GuessClass(val)));
			return this;
		}

		public IQuery SetEnum(int position, Enum val)
		{
			SetParameter(position, val, NHibernateUtil.Enum(val.GetType()));
			return this;
		}

		public IQuery SetAnsiString(string name, string val)
		{
			SetParameter(name, val, NHibernateUtil.AnsiString);
			return this;
		}

		public IQuery SetString(string name, string val)
		{
			SetParameter(name, val, NHibernateUtil.String);
			return this;
		}

		public IQuery SetCharacter(string name, char val)
		{
			SetParameter(name, val, NHibernateUtil.Character);
			return this;
		}

		public IQuery SetBoolean(string name, bool val)
		{
			SetParameter(name, val, NHibernateUtil.Boolean);
			return this;
		}

		public IQuery SetByte(string name, byte val)
		{
			SetParameter(name, val, NHibernateUtil.Byte);
			return this;
		}

		public IQuery SetInt16(string name, short val)
		{
			SetParameter(name, val, NHibernateUtil.Int16);
			return this;
		}

		public IQuery SetInt32(string name, int val)
		{
			SetParameter(name, val, NHibernateUtil.Int32);
			return this;
		}

		public IQuery SetInt64(string name, long val)
		{
			SetParameter(name, val, NHibernateUtil.Int64);
			return this;
		}

		public IQuery SetSingle(string name, float val)
		{
			SetParameter(name, val, NHibernateUtil.Single);
			return this;
		}

		public IQuery SetDouble(string name, double val)
		{
			SetParameter(name, val, NHibernateUtil.Double);
			return this;
		}

		public IQuery SetBinary(string name, byte[] val)
		{
			SetParameter(name, val, NHibernateUtil.Binary);
			return this;
		}

		public IQuery SetDecimal(string name, decimal val)
		{
			SetParameter(name, val, NHibernateUtil.Decimal);
			return this;
		}

		public IQuery SetDateTime(string name, DateTime val)
		{
			SetParameter(name, val, NHibernateUtil.DateTime);
			return this;
		}

		public IQuery SetDateTimeNoMs(string name, DateTime val)
		{
			SetParameter(name, val, NHibernateUtil.DateTimeNoMs);
			return this;
		}

		// Since v5.0
		[Obsolete("Use SetDateTime instead, it uses DateTime2 with dialects supporting it.")]
		public IQuery SetDateTime2(string name, DateTime val)
		{
			SetParameter(name, val, NHibernateUtil.DateTime2);
			return this;
		}

		public IQuery SetTimeSpan(int position, TimeSpan val)
		{
			SetParameter(position, val, NHibernateUtil.TimeSpan);
			return this;
		}

		public IQuery SetTimeSpan(string name, TimeSpan val)
		{
			SetParameter(name, val, NHibernateUtil.TimeSpan);
			return this;
		}

		public IQuery SetTimeAsTimeSpan(int position, TimeSpan val)
		{
			SetParameter(position, val, NHibernateUtil.TimeAsTimeSpan);
			return this;
		}

		public IQuery SetTimeAsTimeSpan(string name, TimeSpan val)
		{
			SetParameter(name, val, NHibernateUtil.TimeAsTimeSpan);
			return this;
		}

		public IQuery SetDateTimeOffset(int position, DateTimeOffset val)
		{
			SetParameter(position, val, NHibernateUtil.DateTimeOffset);
			return this;
		}

		public IQuery SetTime(string name, DateTime val)
		{
			SetParameter(name, val, NHibernateUtil.Time);
			return this;
		}

		// Since v5.0
		[Obsolete("Use SetDateTime instead.")]
		public IQuery SetTimestamp(string name, DateTime val)
		{
			SetParameter(name, val, NHibernateUtil.Timestamp);
			return this;
		}

		public IQuery SetGuid(string name, Guid val)
		{
			SetParameter(name, val, NHibernateUtil.Guid);
			return this;
		}

		public IQuery SetGuid(int position, Guid val)
		{
			SetParameter(position, val, NHibernateUtil.Guid);
			return this;
		}

		public IQuery SetEntity(string name, object val)
		{
			SetParameter(name, val, NHibernateUtil.Entity(NHibernateProxyHelper.GuessClass(val)));
			return this;
		}

		public IQuery SetEnum(string name, Enum val)
		{
			SetParameter(name, val, NHibernateUtil.Enum(val.GetType()));
			return this;
		}

		// Since 5.3
		[Obsolete("This method was never surfaced to a query interface. Use the overload taking an object instead, and supply to it a generic IDictionary<string, object>.")]
		public IQuery SetProperties(IDictionary map)
		{
			string[] @params = NamedParameters;
			for (int i = 0; i < @params.Length; i++)
			{
				var namedParam = @params[i];
				var obj = map[namedParam];
				if (obj == null)
				{
					continue;
				}
				if (obj is IEnumerable && !(obj is string))
				{
					SetParameterList(namedParam, (IEnumerable) obj);
				}
				else
				{
					SetParameter(namedParam, obj, DetermineType(namedParam, obj.GetType()));
				}
			}
			return this;
		}

		private IQuery SetParameters(IDictionary<string, object> map)
		{
			foreach (var namedParam in NamedParameters)
			{
				if (map.TryGetValue(namedParam, out var obj))
				{
					switch (obj)
					{
						case IEnumerable enumerable when !(enumerable is string):
							SetParameterList(namedParam, enumerable);
							break;
						default:
							SetParameter(namedParam, obj);
							break;
					}
				}
			}
			return this;
		}

		private IQuery SetParameters(IDictionary map)
		{
			foreach (var namedParam in NamedParameters)
			{
				var obj = map[namedParam];
				switch (obj)
				{
					case IEnumerable enumerable when !(enumerable is string):
						SetParameterList(namedParam, enumerable);
						break;
					case null when map.Contains(namedParam):
					default:
						SetParameter(namedParam, obj);
						break;
				}
			}
			return this;
		}

		public IQuery SetProperties(object bean)
		{
			if (bean is IDictionary<string, object> map)
			{
				return SetParameters(map);
			}
			if (bean is IDictionary hashtable)
			{
				return SetParameters(hashtable);
			}

			System.Type clazz = bean.GetType();
			string[] @params = NamedParameters;
			for (int i = 0; i < @params.Length; i++)
			{
				string namedParam = @params[i];
				try
				{
					var getter = ReflectHelper.GetGetter(clazz, namedParam, "property");
					var retType = getter.ReturnType;
					var obj = getter.Get(bean);
					if (typeof(IEnumerable).IsAssignableFrom(retType) && retType != typeof(string))
					{
						SetParameterList(namedParam, (IEnumerable) obj);
					}
					else
					{
						SetParameter(namedParam, obj, DetermineType(namedParam, retType));
					}
				}
				catch (PropertyNotFoundException)
				{
					// ignore
				}
			}
			return this;
		}

		public IQuery SetParameterList(string name, IEnumerable vals, IType type)
		{
			if (!parameterMetadata.NamedParameterNames.Contains(name))
			{
				if (shouldIgnoredUnknownNamedParameters)//just ignore it
					return this;

				throw new ArgumentException("Parameter " + name + " does not exist as a named parameter in [" + QueryString + "]");
			}
			if (type == null)
			{
				throw new ArgumentNullException("type","Can't determine the type of parameter-list elements.");
			}
			if(!vals.Cast<object>().Any())
			{
				throw new QueryException(string.Format("An empty parameter-list generates wrong SQL; parameter name '{0}'", name));
			}
			namedParameterLists[name] = new TypedValue(type, vals, true);
			return this;
		}

		public IQuery SetParameterList(string name, IEnumerable vals)
		{
			if (vals == null)
			{
				throw new ArgumentNullException("vals");
			}

			if (!parameterMetadata.NamedParameterNames.Contains(name))
			{
				if (shouldIgnoredUnknownNamedParameters)//just ignore it
					return this;
			}

			object firstValue = vals.Cast<object>().FirstOrDefault();
			SetParameterList(
				name,
				vals,
				firstValue == null
					? ParameterHelper.GuessType(vals.GetCollectionElementType(), session.Factory)
					: DetermineType(name, firstValue));

			return this;
		}

		#endregion

		#region Query properties

		public string QueryString
		{
			get { return queryString; }
		}

		protected internal IDictionary<string, TypedValue> NamedParams
		{
			// NB The java one always returns a copy, so I'm going to reproduce that behaviour
			get { return new Dictionary<string, TypedValue>(namedParameters); }
		}

		protected IDictionary NamedParameterLists
		{
			get { return namedParameterLists; }
		}

		// TODO 6.0: Change type to IList<object>
		protected virtual IList Values
		{
			get { return values; }
		}

		protected virtual IList<IType> Types
		{
			get { return types; }
		}

		public virtual IType[] ReturnTypes
		{
			get { return session.Factory.GetReturnTypes(queryString); }
		}

		public virtual string[] ReturnAliases
		{
			get { return session.Factory.GetReturnAliases(queryString); }
		}
		
		// TODO: maybe call it RowSelection ?
		public RowSelection Selection
		{
			get { return selection; }
		}
		
		public IQuery SetMaxResults(int maxResults)
		{
			selection.MaxRows = maxResults;
			return this;
		}

		public IQuery SetTimeout(int timeout)
		{
			selection.Timeout = timeout;
			return this;
		}

		public IQuery SetFetchSize(int fetchSize)
		{
			selection.FetchSize = fetchSize;
			return this;
		}

		public IQuery SetFirstResult(int firstResult)
		{
			selection.FirstRow = firstResult;
			return this;
		}

		public string[] NamedParameters
		{
			get
			{
				return parameterMetadata.NamedParameterNames.ToArray();
			}
		}

		public abstract IQuery SetLockMode(string alias, LockMode lockMode);

		public IQuery SetComment(string comment)
		{
			this.comment = comment;
			return this;
		}

		internal protected ISessionImplementor Session
		{
			get { return session; }
		}

		protected RowSelection RowSelection
		{
			get { return selection; }
		}

		public IQuery SetCacheable(bool cacheable)
		{
			this.cacheable = cacheable;
			return this;
		}

		public IQuery SetCacheRegion(string cacheRegion)
		{
			if (cacheRegion != null)
				this.cacheRegion = cacheRegion.Trim();
			return this;
		}

		/// <inheritdoc />
		public bool IsReadOnly
		{
			get { return readOnly == null ? Session.PersistenceContext.DefaultReadOnly : readOnly.Value; }
		}

		/// <inheritdoc />
		public IQuery SetReadOnly(bool readOnly)
		{
			this.readOnly = readOnly;
			return this;
		}

		public void SetOptionalId(object optionalId)
		{
			this.optionalId = optionalId;
		}

		public void SetOptionalObject(object optionalObject)
		{
			this.optionalObject = optionalObject;
		}

		public void SetOptionalEntityName(string optionalEntityName)
		{
			this.optionalEntityName = optionalEntityName;
		}

		public IQuery SetFlushMode(FlushMode flushMode)
		{
			this.flushMode = flushMode;
			return this;
		}

		public IQuery SetCollectionKey(object collectionKey)
		{
			this.collectionKey = collectionKey;
			return this;
		}

		public IQuery SetResultTransformer(IResultTransformer transformer)
		{
			resultTransformer = transformer;
			return this;
		}

		public IFutureEnumerable<T> Future<T>()
		{
			return session.GetFutureBatch().AddAsFuture<T>(this);
		}

		public IFutureValue<T> FutureValue<T>()
		{
			return session.GetFutureBatch().AddAsFutureValue<T>(this);
		}

		/// <summary> Override the current session cache mode, just for this query.
		/// </summary>
		/// <param name="cacheMode">The cache mode to use. </param>
		/// <returns> this (for method chaining) </returns>
		public IQuery SetCacheMode(CacheMode cacheMode)
		{
			this.cacheMode = cacheMode;
			return this;
		}

		public IQuery SetIgnoreUknownNamedParameters(bool ignoredUnknownNamedParameters)
		{
			shouldIgnoredUnknownNamedParameters = ignoredUnknownNamedParameters;
			return this;
		}

		protected internal abstract IDictionary<string, LockMode> LockModes { get; }

		#endregion

		#region Execution methods

		public abstract int ExecuteUpdate();
		public abstract IEnumerable Enumerable();
		public abstract IEnumerable<T> Enumerable<T>();
		public abstract IList List();
		public abstract void List(IList results);
		public abstract IList<T> List<T>();
		public T UniqueResult<T>()
		{
			object result = UniqueResult();
			if (result == null && typeof(T).IsValueType)
			{
				return default(T);
			}
			else
			{
				return (T)result;
			}
		}

		public object UniqueResult()
		{
			return UniqueElement(List());
		}

		internal static object UniqueElement(IList list)
		{
			int size = list.Count;
			if (size == 0)
			{
				return null;
			}
			object first = list[0];
			for (int i = 1; i < size; i++)
			{
				if (list[i] != first)
				{
					throw new NonUniqueResultException(size);
				}
			}
			return first;
		}

		public virtual IType[] TypeArray()
		{
			return types.ToArray();
		}

		public virtual object[] ValueArray()
		{
			return values.ToArray();
		}

		public virtual QueryParameters GetQueryParameters()
		{
			return GetQueryParameters(NamedParams);
		}

		public virtual QueryParameters GetQueryParameters(IDictionary<string, TypedValue> namedParams)
		{
			return new QueryParameters(
				TypeArray(),
				ValueArray(),
				namedParams,
				LockModes,
				Selection,
				true,
				IsReadOnly,
				cacheable,
				cacheRegion,
				comment,
				collectionKey == null ? null : new[] { collectionKey },
				optionalObject,
				optionalEntityName,
				optionalId,
				resultTransformer)
			{
				CacheMode = cacheMode
			};
		}

		protected void Before()
		{
			if (flushMode != FlushMode.Unspecified)
			{
				sessionFlushMode = Session.FlushMode;
				Session.FlushMode = flushMode;
			}
			if (cacheMode.HasValue)
			{
				sessionCacheMode = Session.CacheMode;
				Session.CacheMode = cacheMode.Value;
			}
		}

		protected void After()
		{
			if (sessionFlushMode != FlushMode.Unspecified)
			{
				Session.FlushMode = sessionFlushMode;
				sessionFlushMode = FlushMode.Unspecified;
			}
			if (sessionCacheMode.HasValue)
			{
				Session.CacheMode = sessionCacheMode.Value;
				sessionCacheMode = null;
			}
		}

		#endregion

		public override string ToString()
		{
			return queryString;
		}

		protected internal abstract IEnumerable<ITranslator> GetTranslators(ISessionImplementor sessionImplementor, QueryParameters queryParameters);

		// Since v5.2
		[Obsolete("This method has no usages and will be removed in a future version")]
		protected internal abstract Task<IEnumerable<ITranslator>> GetTranslatorsAsync(ISessionImplementor sessionImplementor, QueryParameters queryParameters, CancellationToken cancellationToken);
	}
}