CriterionUtil.cs

namespace NHibernate.Criterion
{
	using System;
	using System.Collections.Generic;
	using Engine;
	using SqlCommand;
	using Type;

	public static class CriterionUtil
	{
		public static SqlString[] GetColumnNames(
			string propertyName,
			IProjection projection,
			ICriteriaQuery criteriaQuery,
			ICriteria criteria)
		{
			if (projection == null)
				return GetColumnNamesUsingPropertyName(criteriaQuery, criteria, propertyName);
			else
				return GetColumnNamesUsingProjection(projection, criteriaQuery, criteria);
		}

		public static SqlString[] GetColumnNamesForSimpleExpression(
			string propertyName,
			IProjection projection,
			ICriteriaQuery criteriaQuery,
			ICriteria criteria,
			ICriterion criterion,
			object value)
		{
			if (projection == null)
			{
				return GetColumnNamesUsingPropertyName(
					criteriaQuery, 
					criteria, 
					propertyName,
					value, 
					criterion);
			}
			else
			{
				return GetColumnNamesUsingProjection(projection, criteriaQuery, criteria);
			}
		}

		internal static SqlString[] GetColumnNamesUsingProjection(IProjection projection, ICriteriaQuery criteriaQuery, ICriteria criteria)
		{
			if (projection is IPropertyProjection propertyProjection)
			{
				return GetColumnNamesUsingPropertyName(criteriaQuery, criteria, propertyProjection.PropertyName);
			}

			return GetProjectionColumns(projection, criteriaQuery, criteria);
		}

		internal static object[] GetColumnNamesAsSqlStringParts(string propertyName, IProjection projection, ICriteriaQuery criteriaQuery, ICriteria criteria)
		{
			if (propertyName != null)
				return criteriaQuery.GetColumnsUsingProjection(criteria, propertyName);
			
			return GetColumnNamesAsSqlStringParts(projection, criteriaQuery, criteria);
		}

		internal static object[] GetColumnNamesAsSqlStringParts(IProjection projection, ICriteriaQuery criteriaQuery, ICriteria criteria)
		{
			if (projection is IPropertyProjection propertyProjection)
			{
				return criteriaQuery.GetColumnsUsingProjection(criteria, propertyProjection.PropertyName);
			}

			return GetProjectionColumns(projection, criteriaQuery, criteria);
		}

		internal static object GetColumnNameAsSqlStringPart(string propertyName, IProjection projection, ICriteriaQuery criteriaQuery, ICriteria criteria)
		{
			var columnNames = GetColumnNamesAsSqlStringParts(propertyName, projection, criteriaQuery, criteria);
			if (columnNames.Length != 1)
			{
				throw new QueryException("property or projection does not map to a single column: " + (propertyName ?? projection.ToString()));
			}

			return columnNames[0];
		}

		internal static object GetColumnNameAsSqlStringPart(IProjection projection, ICriteriaQuery criteriaQuery, ICriteria criteria)
		{
			var columnNames = GetColumnNamesAsSqlStringParts(projection, criteriaQuery, criteria);
			if (columnNames.Length != 1)
			{
				throw new QueryException("property or projection does not map to a single column: " + (projection.ToString()));
			}

			return columnNames[0];
		}

		private static SqlString[] GetProjectionColumns(IProjection projection, ICriteriaQuery criteriaQuery, ICriteria criteria)
		{
			var sqlString = projection.ToSqlString(criteria, criteriaQuery.GetIndexForAlias(), criteriaQuery);
			return new[] {SqlStringHelper.RemoveAsAliasesFromSql(sqlString)};
		}

		private static SqlString[] GetColumnNamesUsingPropertyName(ICriteriaQuery criteriaQuery, ICriteria criteria, string propertyName)
		{
			string[] columnNames = criteriaQuery.GetColumnsUsingProjection(criteria, propertyName);
			return Array.ConvertAll<string, SqlString>(columnNames, delegate(string input) { return new SqlString(input); });
		}

		private static SqlString[] GetColumnNamesUsingPropertyName(
			ICriteriaQuery criteriaQuery, 
			ICriteria criteria, 
			string propertyName, 
			object value, 
			ICriterion critertion)
		{
			string[] columnNames = criteriaQuery.GetColumnsUsingProjection(criteria, propertyName);
			IType propertyType = criteriaQuery.GetTypeUsingProjection(criteria, propertyName);

			if (value != null && !(value is System.Type) && !propertyType.ReturnedClass.IsInstanceOfType(value))
			{
				throw new QueryException(string.Format(
											"Type mismatch in {0}: {1} expected type {2}, actual type {3}",
											critertion.GetType(), propertyName, propertyType.ReturnedClass, value.GetType()));
			}

			if (propertyType.IsCollectionType)
			{
				throw new QueryException(string.Format(
											"cannot use collection property ({0}.{1}) directly in a criterion,"
											+ " use ICriteria.CreateCriteria instead",
											criteriaQuery.GetEntityName(criteria), propertyName));
			}
			return Array.ConvertAll<string, SqlString>(columnNames, delegate(string col)
			{
				return new SqlString(col);
			});
		}

		public static TypedValue[] GetTypedValues(ICriteriaQuery criteriaQuery, ICriteria criteria,
		                                          IProjection projection,
		                                          string propertyName,
		                                          params object[] values)
		{
			List<TypedValue> types = new List<TypedValue>();
			var propertyProjection = projection as IPropertyProjection;
			if (projection == null || propertyProjection != null)
			{
				var pn = propertyProjection != null ? propertyProjection.PropertyName : propertyName;
				foreach (object value in values)
				{
					TypedValue typedValue = criteriaQuery.GetTypedValue(criteria, pn, value); 					
					types.Add(typedValue);
				}
			}
			else
			{
				foreach (object value in values)
				{
					types.Add(new TypedValue(NHibernateUtil.GuessType((object)value), value));
				}
			}
			return types.ToArray();
		}

		public static TypedValue GetTypedValue(
			ICriteriaQuery criteriaQuery,
			ICriteria criteria,
			IProjection projection,
			string propertyName,
			object value)
		{
			if (propertyName != null || (propertyName = (projection as IPropertyProjection)?.PropertyName) != null)
				return criteriaQuery.GetTypedValue(criteria, propertyName, value);

			return new TypedValue(NHibernateUtil.GuessType(value), value);
		}
	}
}