ActiveRecord/Castle.ActiveRecord/Framework/Queries/CountQuery.cs

   1 // Copyright 2004-2008 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 namespace Castle.ActiveRecord.Queries
  16 {
  17         using System;
  18         using NHibernate;
  19         using NHibernate.Criterion;
  20
  21         /// <summary>
  22         /// Query the database for a count (using COUNT(*) ) of all the entites of the specified type.
  23         /// Optionally using a where clause;
  24         /// Note: If Criteria are used, this query can not be included in a MultiQuery.
  25         /// </summary>
  26         public class CountQuery : HqlBasedQuery
  27         {
  28                 // constructors will set EITHER criterias OR detachedCriteria
  29                 private readonly ICriterion[] criterias;
  30                 private readonly DetachedCriteria detachedCriteria;
  31
  32                 /// <summary>
  33                 /// Initializes a new instance of the <see cref="CountQuery"/> class.
  34                 /// </summary>
  35                 /// <param name="targetType">The target type.</param>
  36                 /// <param name="filter">The filter.</param>
  37                 /// <param name="parameters">The parameters.</param>
  38                 public CountQuery(Type targetType, string filter, params object[] parameters)
  39                         : base(targetType, "SELECT COUNT(*) FROM " + targetType.Name + " WHERE " + filter, parameters)
  40                 {
  41                 }
  42
  43                 /// <summary>
  44                 /// Initializes a new instance of the <see cref="CountQuery"/> class.
  45                 /// </summary>
  46                 /// <param name="targetType">The target type.</param>
  47                 public CountQuery(Type targetType) : this(targetType, "1=1", null)
  48                 {
  49                 }
  50
  51                 /// <summary>
  52                 /// Initializes a new instance of the <see cref="CountQuery"/> class.
  53                 /// </summary>
  54                 /// <param name="targetType">The target type.</param>
  55                 /// <param name="criterias">Criteria applied to the query</param>
  56                 public CountQuery(Type targetType, ICriterion[] criterias) : this(targetType, string.Empty, null)
  57                 {
  58                         this.criterias = criterias;
  59                 }
  60
  61                 /// <summary>
  62                 /// Initializes a new instance of the <see cref="CountQuery"/> class.
  63                 /// </summary>
  64                 /// <param name="targetType">The target type.</param>
  65                 /// <param name="detachedCriteria">Criteria applied to the query</param>
  66                 public CountQuery(Type targetType, DetachedCriteria detachedCriteria)
  67                         : this(targetType, string.Empty, null)
  68                 {
  69                         this.detachedCriteria = detachedCriteria;
  70                 }
  71
  72                 /// <summary>
  73                 /// Executes the query.
  74                 /// </summary>
  75                 /// <param name="session">The <c>NHibernate</c>'s <see cref="ISession"/></param>
  76                 /// <returns><c>System.Int32</c> as object</returns>
  77                 protected override object InternalExecute(ISession session)
  78                 {
  79                         if (detachedCriteria != null)
  80                         {
  81                                 ICriteria criteria = detachedCriteria.GetExecutableCriteria(session);
  82
  83                                 criteria.SetProjection(Projections.RowCount());
  84
  85                                 Int32 count = Convert.ToInt32(criteria.UniqueResult());
  86
  87                                 // clear the projection, so our caller can re-use the DetachedCriteria
  88                                 criteria.SetProjection(null);
  89
  90                                 return count;
  91                         }
  92                         else if (criterias != null)
  93                         {
  94                                 ICriteria criteria = session.CreateCriteria(RootType);
  95
  96                                 CriteriaHelper.AddCriterionToCriteria(criteria, criterias);
  97
  98                                 criteria.SetProjection(Projections.RowCount());
  99
 100                                 return Convert.ToInt32(criteria.UniqueResult());
 101                         }
 102                         else
 103                         {
 104                                 return Convert.ToInt32(base.CreateQuery(session).UniqueResult());
 105                         }
 106                 }
 107         }
 108 }