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 #if !NET_2_0
  51         [Serializable]
  52 #endif
  53         [TypeConverterAttribute (typeof (RelationshipConverter))]
  54         public class DataRelation {
  55                 private DataSet dataSet;
  56                 private string relationName;
  57                 private UniqueConstraint parentKeyConstraint;
  58                 private ForeignKeyConstraint childKeyConstraint;
  59                 private DataColumn [] parentColumns;
  60                 private DataColumn [] childColumns;
  61                 private bool nested;
  62                 internal bool createConstraints = true;
  63                 private bool initFinished;
  64                 private PropertyCollection extendedProperties;
  65                 private PropertyChangedEventHandler onPropertyChangingDelegate;
  66
  67                 string _relationName;
  68                 string _parentTableName;
  69                 string _childTableName;
  70                 string [] _parentColumnNames;
  71                 string [] _childColumnNames;
  72                 bool _nested;
  73                 bool initInProgress = false;
  74 #if NET_2_0
  75                 string _parentTableNameSpace = String.Empty;
  76                 string _childTableNameSpace = String.Empty;
  77 #endif
  78
  79                 #region Constructors
  80
  81                 public DataRelation (string relationName, DataColumn parentColumn, DataColumn childColumn)
  82                         : this (relationName, parentColumn, childColumn, true)
  83                 {
  84                 }
  85
  86                 public DataRelation (string relationName, DataColumn [] parentColumns, DataColumn [] childColumns)
  87                         : this (relationName, parentColumns, childColumns, true)
  88                 {
  89                 }
  90
  91                 public DataRelation (string relationName, DataColumn parentColumn, DataColumn childColumn, bool createConstraints)
  92                         : this (relationName, new DataColumn[] { parentColumn }, new DataColumn [] { childColumn }, createConstraints)
  93                 {
  94                 }
  95
  96                 public DataRelation (string relationName, DataColumn [] parentColumns, DataColumn [] childColumns, bool createConstraints)
  97                 {
  98                         this.extendedProperties = new PropertyCollection ();
  99                         this.relationName = relationName == null ? string.Empty : relationName;
 100                         if (parentColumns == null)
 101                                 throw new ArgumentNullException ("parentColumns");
 102                         this.parentColumns = parentColumns;
 103                         if (childColumns == null)
 104                                 throw new ArgumentNullException ("childColumns");
 105                         this.childColumns = childColumns;
 106                         this.createConstraints = createConstraints;
 107                         if (parentColumns.Length != childColumns.Length)
 108                                 throw new ArgumentException ("ParentColumns and ChildColumns should be the same length");
 109                         DataTable parentTable = parentColumns [0].Table;
 110                         DataTable childTable = childColumns [0].Table;
 111                         if (parentTable.DataSet != childTable.DataSet)
 112                                 throw new InvalidConstraintException ();
 113                         foreach (DataColumn column in parentColumns)
 114                                 if (column.Table != parentTable)
 115                                         throw new InvalidConstraintException ();
 116                         foreach (DataColumn column in childColumns)
 117                                 if (column.Table != childTable)
 118                                         throw new InvalidConstraintException ();
 119
 120                         for (int i = 0; i < ChildColumns.Length; i++)
 121                                 if (!parentColumns [i].DataTypeMatches (childColumns [i]))
 122                                         throw new InvalidConstraintException (
 123                                                 "Parent Columns and Child Columns don't have matching column types");
 124                 }
 125
 126                 [Browsable (false)]
 127                 public DataRelation (string relationName, string parentTableName, string childTableName, string [] parentColumnNames, string[] childColumnNames, bool nested)
 128                 {
 129                         _relationName = relationName;
 130                         _parentTableName = parentTableName;
 131                         _childTableName = childTableName;
 132                         _parentColumnNames = parentColumnNames;
 133                         _childColumnNames = childColumnNames;
 134                         _nested = nested;
 135                         InitInProgress = true;
 136                 }
 137
 138 #if NET_2_0
 139                 [Browsable (false)]
 140                 public DataRelation (string relationName, string parentTableName,
 141                                      string parentTableNameSpace, string childTableName,
 142                                      string childTableNameSpace, string[] parentColumnNames,
 143                                      string[] childColumnNames, bool nested)
 144                 {
 145                         _relationName = relationName;
 146                         _parentTableName = parentTableName;
 147                         _parentTableNameSpace = parentTableNameSpace;
 148                         _childTableName = childTableName;
 149                         _childTableNameSpace = childTableNameSpace;
 150                         _parentColumnNames = parentColumnNames;
 151                         _childColumnNames = childColumnNames;
 152                         _nested = nested;
 153                         InitInProgress = true;
 154                 }
 155 #endif
 156
 157                 internal bool InitInProgress {
 158                         get { return initInProgress; }
 159                         set { initInProgress = value; }
 160                 }
 161
 162                 internal void FinishInit (DataSet ds)
 163                 {
 164                         if (!ds.Tables.Contains (_parentTableName) || !ds.Tables.Contains (_childTableName))
 165                                 throw new InvalidOperationException ();
 166
 167                         if (_parentColumnNames.Length != _childColumnNames.Length)
 168                                 throw new InvalidOperationException ();
 169
 170                         DataTable parent = ds.Tables [_parentTableName];
 171                         DataTable child = ds.Tables [_childTableName];
 172
 173                         parentColumns = new DataColumn [_parentColumnNames.Length];
 174                         childColumns = new DataColumn [_childColumnNames.Length];
 175
 176                         for (int i = 0; i < _parentColumnNames.Length; ++i) {
 177                                 if (!parent.Columns.Contains (_parentColumnNames [i]))
 178                                         throw new InvalidOperationException ();
 179                                 parentColumns [i] = parent.Columns [_parentColumnNames [i]];
 180                                 if (!child.Columns.Contains (_childColumnNames [i]))
 181                                         throw new InvalidOperationException ();
 182                                 childColumns [i] = child.Columns [_childColumnNames [i]];
 183                         }
 184
 185                         this.RelationName = _relationName;
 186                         this.Nested = _nested;
 187                         this.initFinished = true;
 188                         this.extendedProperties = new PropertyCollection ();
 189                         InitInProgress = false;
 190 #if NET_2_0
 191                         if (_parentTableNameSpace != String.Empty)
 192                                 parent.Namespace = _parentTableNameSpace;
 193                         if (_childTableNameSpace != String.Empty)
 194                                 child.Namespace = _childTableNameSpace;
 195 #endif
 196                 }
 197
 198                 #endregion // Constructors
 199
 200                 #region Properties
 201
 202                 [DataCategory ("Data")]
 203 #if !NET_2_0
 204                 [DataSysDescription ("Indicates the child columns of this relation.")]
 205 #endif
 206                 public virtual DataColumn [] ChildColumns {
 207                         get { return childColumns; }
 208                 }
 209
 210                 public virtual ForeignKeyConstraint ChildKeyConstraint {
 211                         get { return childKeyConstraint; }
 212                 }
 213
 214                 internal void SetChildKeyConstraint (ForeignKeyConstraint foreignKeyConstraint)
 215                 {
 216                         childKeyConstraint = foreignKeyConstraint;
 217                 }
 218
 219                 public virtual DataTable ChildTable {
 220                         get { return childColumns [0].Table; }
 221                 }
 222
 223                 [Browsable (false)]
 224                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 225                 public virtual DataSet DataSet {
 226                         get { return childColumns [0].Table.DataSet; }
 227                 }
 228
 229                 [Browsable (false)]
 230                 [DataCategory ("Data")]
 231 #if !NET_2_0
 232                 [DataSysDescription ("The collection that holds custom user information.")]
 233 #endif
 234                 public PropertyCollection ExtendedProperties {
 235                         get {
 236                                 if (extendedProperties == null)
 237                                         extendedProperties = new PropertyCollection();
 238                                 return extendedProperties;
 239                         }
 240                 }
 241
 242                 [DataCategory ("Data")]
 243 #if !NET_2_0
 244                 [DataSysDescription ("Indicates whether relations are nested.")]
 245 #endif
 246                 [DefaultValue (false)]
 247                 public virtual bool Nested {
 248                         get { return nested; }
 249                         set { nested = value; }
 250                 }
 251
 252                 [DataCategory ("Data")]
 253 #if !NET_2_0
 254                 [DataSysDescription ("Indicates the parent columns of this relation.")]
 255 #endif
 256                 public virtual DataColumn[] ParentColumns {
 257                         get { return parentColumns; }
 258                 }
 259
 260                 public virtual UniqueConstraint ParentKeyConstraint {
 261                         get { return parentKeyConstraint; }
 262                 }
 263
 264                 internal void SetParentKeyConstraint (UniqueConstraint uniqueConstraint)
 265                 {
 266                         parentKeyConstraint = uniqueConstraint;
 267                 }
 268
 269                 internal void SetDataSet (DataSet ds)
 270                 {
 271                         dataSet = ds;
 272                 }
 273
 274                 public virtual DataTable ParentTable {
 275                         get { return parentColumns [0].Table; }
 276                 }
 277
 278                 [DataCategory ("Data")]
 279 #if !NET_2_0
 280                 [DataSysDescription ("The name used to look up this relation in the Relations collection of a DataSet.")]
 281 #endif
 282                 [DefaultValue ("")]
 283                 public virtual string RelationName {
 284                         get { return relationName; }
 285                         set { relationName = value; }
 286                 }
 287
 288                 #endregion // Properties
 289
 290                 #region Methods
 291
 292                 protected void CheckStateForProperty ()
 293                 {
 294                         // TODO: check consistency of constraints
 295                         DataTable parentTable = parentColumns [0].Table;
 296                         DataTable childTable = childColumns [0].Table;
 297                         if (parentTable.DataSet != childTable.DataSet)
 298                                 throw new DataException ();
 299                         bool allColumnsEqual = false;
 300                         for (int colCnt = 0; colCnt < parentColumns.Length; ++colCnt) {
 301                                 if (!parentColumns [colCnt].DataType.Equals (childColumns [colCnt].DataType))
 302                                         throw new DataException ();
 303                                 if (parentColumns [colCnt] != childColumns [colCnt])
 304                                         allColumnsEqual = false;
 305                         }
 306                         if (allColumnsEqual)
 307                                 throw new DataException ();
 308                 }
 309
 310                 protected internal void OnPropertyChanging (PropertyChangedEventArgs pcevent)
 311                 {
 312                         if (onPropertyChangingDelegate != null)
 313                                 onPropertyChangingDelegate (this, pcevent);
 314                 }
 315
 316                 protected internal void RaisePropertyChanging (string name)
 317                 {
 318                         OnPropertyChanging(new PropertyChangedEventArgs(name));
 319                 }
 320
 321                 public override string ToString ()
 322                 {
 323                         return relationName;
 324                 }
 325
 326                 internal void UpdateConstraints ()
 327                 {
 328                         if (initFinished || ! createConstraints)
 329                                 return;
 330
 331                         ForeignKeyConstraint    foreignKeyConstraint    = null;
 332                         UniqueConstraint        uniqueConstraint        = null;
 333
 334                         foreignKeyConstraint    = FindForeignKey (ChildTable.Constraints);
 335                         uniqueConstraint        = FindUniqueConstraint (ParentTable.Constraints);
 336
 337                         // if we did not find the unique constraint in the parent table.
 338                         // we generate new uniqueConstraint and add it to the parent table.
 339                         if (uniqueConstraint == null) {
 340                                 uniqueConstraint = new UniqueConstraint (ParentColumns, false);
 341                                 ParentTable.Constraints.Add (uniqueConstraint);
 342                         }
 343
 344                         // if we did not find the foreign key constraint in the parent table.
 345                         // we generate new foreignKeyConstraint and add it to the parent table.
 346                         if (foreignKeyConstraint == null) {
 347                                 foreignKeyConstraint = new ForeignKeyConstraint (RelationName,
 348                                                                                  ParentColumns,
 349                                                                                  ChildColumns);
 350                                 ChildTable.Constraints.Add (foreignKeyConstraint);
 351                         }
 352
 353                         SetParentKeyConstraint (uniqueConstraint);
 354                         SetChildKeyConstraint (foreignKeyConstraint);
 355                 }
 356
 357                 private static bool CompareDataColumns (DataColumn [] dc1, DataColumn [] dc2)
 358                 {
 359                         if (dc1.Length != dc2.Length)
 360                                 return false;
 361
 362                         for (int columnCnt = 0; columnCnt < dc1.Length; ++columnCnt){
 363                                 if (dc1 [columnCnt] != dc2 [columnCnt])
 364                                         return false;
 365                         }
 366                         return true;
 367                 }
 368
 369                 private ForeignKeyConstraint FindForeignKey (ConstraintCollection cl)
 370                 {
 371                         ForeignKeyConstraint fkc = null;
 372                         foreach (Constraint o in cl) {
 373                                 if (! (o is ForeignKeyConstraint))
 374                                         continue;
 375                                 fkc = (ForeignKeyConstraint) o;
 376                                 /* Check ChildColumns & ParentColumns */
 377                                 if (CompareDataColumns (ChildColumns, fkc.Columns) &&
 378                                     CompareDataColumns (ParentColumns, fkc.RelatedColumns))
 379                                         return fkc;
 380                         }
 381                         return null;
 382                 }
 383
 384                 private UniqueConstraint FindUniqueConstraint (ConstraintCollection cl)
 385                 {
 386                         UniqueConstraint uc = null;
 387                         // find if the unique constraint already exists in the parent table.
 388                         foreach (Constraint o in cl){
 389                                 if (! (o is UniqueConstraint))
 390                                         continue;
 391                                 uc = (UniqueConstraint) o;
 392                                 //Check in ParentColumns
 393                                 if (CompareDataColumns (ParentColumns, uc.Columns))
 394                                         return uc;
 395                         }
 396                         return null;
 397                 }
 398
 399                 /// <summary>
 400                 ///     Check whether the given column is part of this relation.
 401                 /// <summary>
 402                 /// <returns>
 403                 ///     true if the column is part of this relation, otherwise false.
 404                 /// </returns>
 405                 internal bool Contains (DataColumn column)
 406                 {
 407                         foreach (DataColumn col in ParentColumns)
 408                                 if (col == column)
 409                                         return true;
 410
 411                         foreach (DataColumn col in ChildColumns)
 412                                 if (col == column)
 413                                         return true;
 414                         return false;
 415                 }
 416
 417                 #endregion // Methods
 418         }
 419 }