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 //   Tim Coleman <tim@timcoleman.com>
   8 //
   9 // (C) 2002 Daniel Morgan
  10 // (C) 2002 Ximian, Inc.
  11 // Copyright (C) Tim Coleman, 2003
  12 //
  13
  14 //
  15 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  16 //
  17 // Permission is hereby granted, free of charge, to any person obtaining
  18 // a copy of this software and associated documentation files (the
  19 // "Software"), to deal in the Software without restriction, including
  20 // without limitation the rights to use, copy, modify, merge, publish,
  21 // distribute, sublicense, and/or sell copies of the Software, and to
  22 // permit persons to whom the Software is furnished to do so, subject to
  23 // the following conditions:
  24 //
  25 // The above copyright notice and this permission notice shall be
  26 // included in all copies or substantial portions of the Software.
  27 //
  28 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  29 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  30 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  31 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  32 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  33 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  34 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  35 //
  36
  37 using System;
  38 using System.ComponentModel;
  39 using System.Runtime.Serialization;
  40
  41 namespace System.Data
  42 {
  43         /// <summary>
  44         /// DataRelation is used for a parent/child relationship
  45         /// between two DataTable objects
  46         /// </summary>
  47         [Editor ("Microsoft.VSDesigner.Data.Design.DataRelationEditor, " + Consts.AssemblyMicrosoft_VSDesigner,
  48                  "System.Drawing.Design.UITypeEditor, " + Consts.AssemblySystem_Drawing)]
  49         [DefaultProperty ("RelationName")]
  50         [TypeConverterAttribute (typeof (RelationshipConverter))]
  51         public class DataRelation {
  52                 private DataSet dataSet;
  53                 private string relationName;
  54                 private UniqueConstraint parentKeyConstraint;
  55                 private ForeignKeyConstraint childKeyConstraint;
  56                 private DataColumn [] parentColumns;
  57                 private DataColumn [] childColumns;
  58                 private bool nested;
  59                 internal bool createConstraints = true;
  60                 private bool initFinished;
  61                 private PropertyCollection extendedProperties;
  62                 private PropertyChangedEventHandler onPropertyChangingDelegate;
  63
  64                 string _relationName;
  65                 string _parentTableName;
  66                 string _childTableName;
  67                 string [] _parentColumnNames;
  68                 string [] _childColumnNames;
  69                 bool _nested;
  70                 bool initInProgress = false;
  71                 string _parentTableNameSpace = String.Empty;
  72                 string _childTableNameSpace = String.Empty;
  73
  74                 #region Constructors
  75
  76                 public DataRelation (string relationName, DataColumn parentColumn, DataColumn childColumn)
  77                         : this (relationName, parentColumn, childColumn, true)
  78                 {
  79                 }
  80
  81                 public DataRelation (string relationName, DataColumn [] parentColumns, DataColumn [] childColumns)
  82                         : this (relationName, parentColumns, childColumns, true)
  83                 {
  84                 }
  85
  86                 public DataRelation (string relationName, DataColumn parentColumn, DataColumn childColumn, bool createConstraints)
  87                         : this (relationName, new DataColumn[] { parentColumn }, new DataColumn [] { childColumn }, createConstraints)
  88                 {
  89                 }
  90
  91                 public DataRelation (string relationName, DataColumn [] parentColumns, DataColumn [] childColumns, bool createConstraints)
  92                 {
  93                         this.extendedProperties = new PropertyCollection ();
  94                         this.relationName = relationName == null ? string.Empty : relationName;
  95                         if (parentColumns == null)
  96                                 throw new ArgumentNullException ("parentColumns");
  97                         this.parentColumns = parentColumns;
  98                         if (childColumns == null)
  99                                 throw new ArgumentNullException ("childColumns");
 100                         this.childColumns = childColumns;
 101                         this.createConstraints = createConstraints;
 102                         if (parentColumns.Length != childColumns.Length)
 103                                 throw new ArgumentException ("ParentColumns and ChildColumns should be the same length");
 104                         DataTable parentTable = parentColumns [0].Table;
 105                         DataTable childTable = childColumns [0].Table;
 106                         if (parentTable.DataSet != childTable.DataSet)
 107                                 throw new InvalidConstraintException ();
 108                         foreach (DataColumn column in parentColumns)
 109                                 if (column.Table != parentTable)
 110                                         throw new InvalidConstraintException ();
 111                         foreach (DataColumn column in childColumns)
 112                                 if (column.Table != childTable)
 113                                         throw new InvalidConstraintException ();
 114
 115                         for (int i = 0; i < ChildColumns.Length; i++)
 116                                 if (!parentColumns [i].DataTypeMatches (childColumns [i]))
 117                                         throw new InvalidConstraintException (
 118                                                 "Parent Columns and Child Columns don't have matching column types");
 119                 }
 120
 121                 [Browsable (false)]
 122                 public DataRelation (string relationName, string parentTableName, string childTableName, string [] parentColumnNames, string[] childColumnNames, bool nested)
 123                 {
 124                         _relationName = relationName;
 125                         _parentTableName = parentTableName;
 126                         _childTableName = childTableName;
 127                         _parentColumnNames = parentColumnNames;
 128                         _childColumnNames = childColumnNames;
 129                         _nested = nested;
 130                         InitInProgress = true;
 131                 }
 132
 133                 [Browsable (false)]
 134                 public DataRelation (string relationName, string parentTableName,
 135                                      string parentTableNamespace, string childTableName,
 136                                      string childTableNamespace, string[] parentColumnNames,
 137                                      string[] childColumnNames, bool nested)
 138                 {
 139                         _relationName = relationName;
 140                         _parentTableName = parentTableName;
 141                         _parentTableNameSpace = parentTableNamespace;
 142                         _childTableName = childTableName;
 143                         _childTableNameSpace = childTableNamespace;
 144                         _parentColumnNames = parentColumnNames;
 145                         _childColumnNames = childColumnNames;
 146                         _nested = nested;
 147                         InitInProgress = true;
 148                 }
 149
 150                 internal bool InitInProgress {
 151                         get { return initInProgress; }
 152                         set { initInProgress = value; }
 153                 }
 154
 155                 internal void FinishInit (DataSet ds)
 156                 {
 157                         if (!ds.Tables.Contains (_parentTableName) || !ds.Tables.Contains (_childTableName))
 158                                 throw new InvalidOperationException ();
 159
 160                         if (_parentColumnNames.Length != _childColumnNames.Length)
 161                                 throw new InvalidOperationException ();
 162
 163                         DataTable parent = ds.Tables [_parentTableName];
 164                         DataTable child = ds.Tables [_childTableName];
 165
 166                         parentColumns = new DataColumn [_parentColumnNames.Length];
 167                         childColumns = new DataColumn [_childColumnNames.Length];
 168
 169                         for (int i = 0; i < _parentColumnNames.Length; ++i) {
 170                                 if (!parent.Columns.Contains (_parentColumnNames [i]))
 171                                         throw new InvalidOperationException ();
 172                                 parentColumns [i] = parent.Columns [_parentColumnNames [i]];
 173                                 if (!child.Columns.Contains (_childColumnNames [i]))
 174                                         throw new InvalidOperationException ();
 175                                 childColumns [i] = child.Columns [_childColumnNames [i]];
 176                         }
 177
 178                         this.RelationName = _relationName;
 179                         this.Nested = _nested;
 180                         this.initFinished = true;
 181                         this.extendedProperties = new PropertyCollection ();
 182                         InitInProgress = false;
 183                         if (_parentTableNameSpace != String.Empty)
 184                                 parent.Namespace = _parentTableNameSpace;
 185                         if (_childTableNameSpace != String.Empty)
 186                                 child.Namespace = _childTableNameSpace;
 187                 }
 188
 189                 #endregion // Constructors
 190
 191                 #region Properties
 192
 193                 [DataCategory ("Data")]
 194                 public virtual DataColumn [] ChildColumns {
 195                         get { return childColumns; }
 196                 }
 197
 198                 public virtual ForeignKeyConstraint ChildKeyConstraint {
 199                         get { return childKeyConstraint; }
 200                 }
 201
 202                 internal void SetChildKeyConstraint (ForeignKeyConstraint foreignKeyConstraint)
 203                 {
 204                         childKeyConstraint = foreignKeyConstraint;
 205                 }
 206
 207                 public virtual DataTable ChildTable {
 208                         get { return childColumns [0].Table; }
 209                 }
 210
 211                 [Browsable (false)]
 212                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 213                 public virtual DataSet DataSet {
 214                         get { return childColumns [0].Table.DataSet; }
 215                 }
 216
 217                 [Browsable (false)]
 218                 [DataCategory ("Data")]
 219                 public PropertyCollection ExtendedProperties {
 220                         get {
 221                                 if (extendedProperties == null)
 222                                         extendedProperties = new PropertyCollection();
 223                                 return extendedProperties;
 224                         }
 225                 }
 226
 227                 [DataCategory ("Data")]
 228                 [DefaultValue (false)]
 229                 public virtual bool Nested {
 230                         get { return nested; }
 231                         set { nested = value; }
 232                 }
 233
 234                 [DataCategory ("Data")]
 235                 public virtual DataColumn[] ParentColumns {
 236                         get { return parentColumns; }
 237                 }
 238
 239                 public virtual UniqueConstraint ParentKeyConstraint {
 240                         get { return parentKeyConstraint; }
 241                 }
 242
 243                 internal void SetParentKeyConstraint (UniqueConstraint uniqueConstraint)
 244                 {
 245                         parentKeyConstraint = uniqueConstraint;
 246                 }
 247
 248                 internal void SetDataSet (DataSet ds)
 249                 {
 250                         dataSet = ds;
 251                 }
 252
 253                 public virtual DataTable ParentTable {
 254                         get { return parentColumns [0].Table; }
 255                 }
 256
 257                 [DataCategory ("Data")]
 258                 [DefaultValue ("")]
 259                 public virtual string RelationName {
 260                         get { return relationName; }
 261                         set { relationName = value; }
 262                 }
 263
 264                 #endregion // Properties
 265
 266                 #region Methods
 267
 268                 protected void CheckStateForProperty ()
 269                 {
 270                         // TODO: check consistency of constraints
 271                         DataTable parentTable = parentColumns [0].Table;
 272                         DataTable childTable = childColumns [0].Table;
 273                         if (parentTable.DataSet != childTable.DataSet)
 274                                 throw new DataException ();
 275                         bool allColumnsEqual = false;
 276                         for (int colCnt = 0; colCnt < parentColumns.Length; ++colCnt) {
 277                                 if (!parentColumns [colCnt].DataType.Equals (childColumns [colCnt].DataType))
 278                                         throw new DataException ();
 279                                 if (parentColumns [colCnt] != childColumns [colCnt])
 280                                         allColumnsEqual = false;
 281                         }
 282                         if (allColumnsEqual)
 283                                 throw new DataException ();
 284                 }
 285
 286                 protected internal void OnPropertyChanging (PropertyChangedEventArgs pcevent)
 287                 {
 288                         if (onPropertyChangingDelegate != null)
 289                                 onPropertyChangingDelegate (this, pcevent);
 290                 }
 291
 292                 protected internal void RaisePropertyChanging (string name)
 293                 {
 294                         OnPropertyChanging(new PropertyChangedEventArgs(name));
 295                 }
 296
 297                 public override string ToString ()
 298                 {
 299                         return relationName;
 300                 }
 301
 302                 internal void UpdateConstraints ()
 303                 {
 304                         if (initFinished || ! createConstraints)
 305                                 return;
 306
 307                         ForeignKeyConstraint    foreignKeyConstraint    = null;
 308                         UniqueConstraint        uniqueConstraint        = null;
 309
 310                         foreignKeyConstraint    = FindForeignKey (ChildTable.Constraints);
 311                         uniqueConstraint        = FindUniqueConstraint (ParentTable.Constraints);
 312
 313                         // if we did not find the unique constraint in the parent table.
 314                         // we generate new uniqueConstraint and add it to the parent table.
 315                         if (uniqueConstraint == null) {
 316                                 uniqueConstraint = new UniqueConstraint (ParentColumns, false);
 317                                 ParentTable.Constraints.Add (uniqueConstraint);
 318                         }
 319
 320                         // if we did not find the foreign key constraint in the parent table.
 321                         // we generate new foreignKeyConstraint and add it to the parent table.
 322                         if (foreignKeyConstraint == null) {
 323                                 foreignKeyConstraint = new ForeignKeyConstraint (RelationName,
 324                                                                                  ParentColumns,
 325                                                                                  ChildColumns);
 326                                 ChildTable.Constraints.Add (foreignKeyConstraint);
 327                         }
 328
 329                         SetParentKeyConstraint (uniqueConstraint);
 330                         SetChildKeyConstraint (foreignKeyConstraint);
 331                 }
 332
 333                 private static bool CompareDataColumns (DataColumn [] dc1, DataColumn [] dc2)
 334                 {
 335                         if (dc1.Length != dc2.Length)
 336                                 return false;
 337
 338                         for (int columnCnt = 0; columnCnt < dc1.Length; ++columnCnt){
 339                                 if (dc1 [columnCnt] != dc2 [columnCnt])
 340                                         return false;
 341                         }
 342                         return true;
 343                 }
 344
 345                 private ForeignKeyConstraint FindForeignKey (ConstraintCollection cl)
 346                 {
 347                         ForeignKeyConstraint fkc = null;
 348                         foreach (Constraint o in cl) {
 349                                 if (! (o is ForeignKeyConstraint))
 350                                         continue;
 351                                 fkc = (ForeignKeyConstraint) o;
 352                                 /* Check ChildColumns & ParentColumns */
 353                                 if (CompareDataColumns (ChildColumns, fkc.Columns) &&
 354                                     CompareDataColumns (ParentColumns, fkc.RelatedColumns))
 355                                         return fkc;
 356                         }
 357                         return null;
 358                 }
 359
 360                 private UniqueConstraint FindUniqueConstraint (ConstraintCollection cl)
 361                 {
 362                         UniqueConstraint uc = null;
 363                         // find if the unique constraint already exists in the parent table.
 364                         foreach (Constraint o in cl){
 365                                 if (! (o is UniqueConstraint))
 366                                         continue;
 367                                 uc = (UniqueConstraint) o;
 368                                 //Check in ParentColumns
 369                                 if (CompareDataColumns (ParentColumns, uc.Columns))
 370                                         return uc;
 371                         }
 372                         return null;
 373                 }
 374
 375                 /// <summary>
 376                 ///     Check whether the given column is part of this relation.
 377                 /// <summary>
 378                 /// <returns>
 379                 ///     true if the column is part of this relation, otherwise false.
 380                 /// </returns>
 381                 internal bool Contains (DataColumn column)
 382                 {
 383                         foreach (DataColumn col in ParentColumns)
 384                                 if (col == column)
 385                                         return true;
 386
 387                         foreach (DataColumn col in ChildColumns)
 388                                 if (col == column)
 389                                         return true;
 390                         return false;
 391                 }
 392
 393                 #endregion // Methods
 394         }
 395 }