2 // System.Data.Constraint.cs
5 // Franklin Wise <gracenote@earthlink.net>
7 // Tim Coleman (tim@timcoleman.com)
10 // (C) Ximian, Inc. 2002
11 // Copyright (C) Tim Coleman, 2002
15 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
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:
25 // The above copyright notice and this permission notice shall be
26 // included in all copies or substantial portions of the Software.
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.
38 using System.Collections;
39 using System.ComponentModel;
40 using System.Runtime.InteropServices;
41 using System.Runtime.Serialization;
42 using System.Data.Common;
44 namespace System.Data {
46 internal delegate void DelegateConstraintNameChange (object sender, string newName);
48 [DefaultProperty ("ConstraintName")]
52 [TypeConverterAttribute (typeof (ConstraintConverter))]
53 public abstract class Constraint
55 internal event DelegateConstraintNameChange BeforeConstraintNameChange;
57 //if constraintName is not set then a name is
58 //created when it is added to
59 //the ConstraintCollection
60 //it can not be set to null, empty or duplicate
61 //once it has been added to the collection
62 private string _constraintName;
63 private PropertyCollection _properties;
67 //Used for membership checking
68 private ConstraintCollection _constraintCollection;
72 protected Constraint ()
75 _properties = new PropertyCollection();
78 [CLSCompliant (false)]
79 protected internal virtual DataSet _DataSet {
80 get { return dataSet; }
83 [DataCategory ("Data")]
85 [DataSysDescription ("Indicates the name of this constraint.")]
88 public virtual string ConstraintName {
89 get{ return _constraintName == null ? "" : _constraintName; }
91 //This should only throw an exception when it
92 //is a member of a ConstraintCollection which
93 //means we should let the ConstraintCollection
94 //handle exceptions when this value changes
95 _onConstraintNameChange(value);
96 _constraintName = value;
101 [DataCategory ("Data")]
103 [DataSysDescription ("The collection that holds custom user information.")]
105 public PropertyCollection ExtendedProperties {
106 get { return _properties; }
108 internal set { _properties = value; }
113 [DataSysDescription ("Indicates the table of this constraint.")]
115 public abstract DataTable Table {
119 internal ConstraintCollection ConstraintCollection {
120 get{ return _constraintCollection; }
121 set{ _constraintCollection = value; }
124 private void _onConstraintNameChange (string newName)
126 if (null != BeforeConstraintNameChange)
128 BeforeConstraintNameChange (this, newName);
132 //call once before adding a constraint to a collection
133 //will throw an exception to prevent the add if a rule is broken
134 internal abstract void AddToConstraintCollectionSetup (ConstraintCollection collection);
136 internal abstract bool IsConstraintViolated ();
138 internal static void ThrowConstraintException(){
139 throw new ConstraintException("Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.");
142 bool initInProgress = false;
143 internal virtual bool InitInProgress {
144 get { return initInProgress; }
145 set { initInProgress = value; }
148 internal virtual void FinishInit (DataTable table)
152 internal void AssertConstraint()
154 // The order is important.. IsConstraintViolated fills the RowErrors if it detects
156 if (!IsConstraintViolated())
158 if (Table._duringDataLoad || (Table.DataSet != null && !Table.DataSet.EnforceConstraints))
160 ThrowConstraintException();
163 internal abstract void AssertConstraint(DataRow row);
165 internal virtual void RollbackAssert (DataRow row)
169 //call once before removing a constraint to a collection
170 //can throw an exception to prevent the removal
171 internal abstract void RemoveFromConstraintCollectionCleanup (ConstraintCollection collection);
174 protected void CheckStateForProperty ()
176 throw new NotImplementedException ();
179 protected internal void SetDataSet (DataSet dataSet)
181 this.dataSet = dataSet;
190 if (_index != null) {
192 Table.DropIndex(_index);
197 if (_index != null) {
203 internal abstract bool IsColumnContained(DataColumn column);
204 internal abstract bool CanRemoveFromCollection(ConstraintCollection col, bool shouldThrow);
207 /// Gets the ConstraintName, if there is one, as a string.
209 public override string ToString ()
211 return _constraintName == null ? "" : _constraintName;