mcs/class/System.Data/System.Data/DataRelation.cs

   1 //
   2 // System.Data.DataRelation.cs
   3 //
   4 // Author:
   5 //   Daniel Morgan <danmorg@sc.rr.com>
   6 //   Alan Tam Siu Lung <Tam@SiuLung.com>
   7 //
   8 // (C) 2002 Daniel Morgan
   9 // (C) 2002 Ximian, Inc.
  10 //
  11
  12 using System;
  13 using System.ComponentModel;
  14 using System.Runtime.Serialization;
  15
  16 namespace System.Data
  17 {
  18         /// <summary>
  19         /// DataRelation is used for a parent/child relationship
  20         /// between two DataTable objects
  21         /// </summary>
  22         [Editor]
  23         [DefaultProperty ("RelationName")]
  24         [Serializable]
  25         public class DataRelation {
  26                 private DataSet dataSet;
  27                 private string relationName;
  28                 private UniqueConstraint parentKeyConstraint;
  29                 private ForeignKeyConstraint childKeyConstraint;
  30                 private DataColumn[] parentColumns;
  31                 private DataColumn[] childColumns;
  32                 private bool nested;
  33                 internal bool createConstraints;
  34                 private PropertyCollection extendedProperties;
  35                 private PropertyChangedEventHandler onPropertyChangingDelegate;
  36
  37                 #region Constructors
  38
  39                 public DataRelation (string relationName, DataColumn parentColumn, DataColumn childColumn)
  40                 : this(relationName, parentColumn, childColumn, true)
  41                 {
  42                 }
  43
  44                 public DataRelation (string relationName, DataColumn[] parentColumns, DataColumn[] childColumns)
  45                 : this(relationName, parentColumns, childColumns, true)
  46                 {
  47                 }
  48
  49                 public DataRelation (string relationName, DataColumn parentColumn, DataColumn childColumn, bool createConstraints)
  50                 : this(relationName, new DataColumn[] { parentColumn }, new DataColumn[] { childColumn }, createConstraints)
  51                 {
  52                 }
  53
  54                 public DataRelation (string relationName, DataColumn[] parentColumns, DataColumn[] childColumns, bool createConstraints)
  55                 {
  56                         this.extendedProperties = new PropertyCollection();
  57                         if (relationName == null) relationName = string.Empty;
  58                         this.relationName = relationName;
  59                         if (parentColumns == null) throw new ArgumentNullException ();
  60                         this.parentColumns = parentColumns;
  61                         if (childColumns == null) throw new ArgumentNullException ();
  62                         this.childColumns = childColumns;
  63                         this.createConstraints = createConstraints;
  64                         if (parentColumns.Length != childColumns.Length)
  65                                 throw new InvalidConstraintException ();
  66                         DataTable parentTable = parentColumns[0].Table;
  67                         DataTable childTable = childColumns[0].Table;
  68                         if (parentTable.DataSet != childTable.DataSet)
  69                                 throw new InvalidConstraintException ();
  70                         foreach (DataColumn column in parentColumns)
  71                                 if (column.Table != parentTable)
  72                                         throw new InvalidConstraintException ();
  73                         foreach (DataColumn column in childColumns)
  74                                 if (column.Table != childTable)
  75                                         throw new InvalidConstraintException ();
  76                 }
  77
  78                 [MonoTODO]
  79                 [Browsable (false)]
  80                 public DataRelation (string relationName, string parentTableName, string childTableName, string[] parentColumnNames, string[] childColumnNames, bool nested)
  81                 {
  82                         throw new NotImplementedException ();
  83                 }
  84
  85                 #endregion // Constructors
  86
  87                 #region Properties
  88
  89                 [DataCategory ("Data")]
  90                 [DataSysDescription ("Indicates the child columns of this relation.")]
  91                 public virtual DataColumn[] ChildColumns {
  92                         get {
  93                                 return childColumns;
  94                         }
  95                 }
  96
  97                 public virtual ForeignKeyConstraint ChildKeyConstraint {
  98                         get {
  99                                 return childKeyConstraint;
 100                         }
 101                 }
 102
 103                 internal void SetChildKeyConstraint(ForeignKeyConstraint foreignKeyConstraint) {
 104                         childKeyConstraint = foreignKeyConstraint;
 105                 }
 106
 107                 public virtual DataTable ChildTable {
 108                         get {
 109                                 return childColumns[0].Table;
 110                         }
 111                 }
 112
 113                 [Browsable (false)]
 114                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 115                 public virtual DataSet DataSet {
 116                         get {
 117                                 return childColumns[0].Table.DataSet;
 118                         }
 119                 }
 120
 121                 [Browsable (false)]
 122                 [DataCategory ("Data")]
 123                 [DataSysDescription ("The collection that holds custom user information.")]
 124                 public PropertyCollection ExtendedProperties {
 125                         get {
 126                                 if (extendedProperties == null)
 127                                         extendedProperties = new PropertyCollection();
 128                                 return extendedProperties;
 129                         }
 130                 }
 131
 132                 [DataCategory ("Data")]
 133                 [DataSysDescription ("Indicates whether relations are nested.")]
 134                 [DefaultValue (false)]
 135                 public virtual bool Nested {
 136                         get {
 137                                 return nested;
 138                         }
 139
 140                         set {
 141                                 nested = value;
 142                         }
 143                 }
 144
 145                 [DataCategory ("Data")]
 146                 [DataSysDescription ("Indicates the parent columns of this relation.")]
 147                 public virtual DataColumn[] ParentColumns {
 148                         get {
 149                                 return parentColumns;
 150                         }
 151                 }
 152
 153                 public virtual UniqueConstraint ParentKeyConstraint {
 154                         get {
 155                                 return parentKeyConstraint;
 156                         }
 157                 }
 158
 159                 internal void SetParentKeyConstraint(UniqueConstraint uniqueConstraint) {
 160                         parentKeyConstraint = uniqueConstraint;
 161                 }
 162
 163                 internal void SetDataSet(DataSet ds) {
 164                         dataSet = ds;
 165                 }
 166
 167                 public virtual DataTable ParentTable {
 168                         get {
 169                                 return parentColumns[0].Table;
 170                         }
 171                 }
 172
 173                 [DataCategory ("Data")]
 174                 [DataSysDescription ("The name used to look up this relation in the Relations collection of a DataSet.")]
 175                 [DefaultValue ("")]
 176                 public virtual string RelationName {
 177                         get {
 178                                 return relationName;
 179                         }
 180
 181                         set {
 182                                 relationName = value;
 183                         }
 184                 }
 185
 186                 #endregion // Properties
 187
 188                 #region Methods
 189
 190                 protected void CheckStateForProperty ()
 191                 {
 192                         // TODO: check consistency of constraints
 193                         DataTable parentTable = parentColumns[0].Table;
 194                         DataTable childTable = parentColumns[0].Table;
 195                         if (parentTable.DataSet != childTable.DataSet)
 196                                 throw new DataException ();
 197                         bool allColumnsEqual = false;
 198                         for (int colCnt = 0; colCnt < parentColumns.Length; ++colCnt) {
 199                                 if (!parentColumns [colCnt].DataType.Equals (childColumns [colCnt].DataType))
 200                                         throw new DataException ();
 201                                 if (parentColumns [colCnt] != childColumns [colCnt]) allColumnsEqual = false;
 202                         }
 203                         if (allColumnsEqual) throw new DataException ();
 204                 }
 205
 206                 protected internal void OnPropertyChanging (PropertyChangedEventArgs pcevent)
 207                 {
 208                         if (onPropertyChangingDelegate != null)
 209                                 onPropertyChangingDelegate (this, pcevent);
 210                 }
 211
 212                 protected internal void RaisePropertyChanging (string name)
 213                 {
 214                         OnPropertyChanging(new PropertyChangedEventArgs(name));
 215                 }
 216
 217                 public override string ToString ()
 218                 {
 219                         return relationName;
 220                 }
 221
 222                 #endregion // Methods
 223         }
 224 }