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//------------------------------------------------------------------------------
// <copyright file="UniqueConstraint.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
// <owner current="false" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
namespace System.Data {
using System;
using System.Diagnostics;
using System.ComponentModel;
/// <devdoc>
/// <para>
/// Represents a restriction on a set of columns in which all values must be unique.
/// </para>
/// </devdoc>
[
DefaultProperty("ConstraintName"),
Editor("Microsoft.VSDesigner.Data.Design.UniqueConstraintEditor, " + AssemblyRef.MicrosoftVSDesigner, "System.Drawing.Design.UITypeEditor, " + AssemblyRef.SystemDrawing),
]
public class UniqueConstraint : Constraint {
private DataKey key;
private Index _constraintIndex;
internal bool bPrimaryKey = false;
// Design time serialization
internal string constraintName = null;
internal string[] columnNames = null;
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the specified name and
/// <see cref='System.Data.DataColumn'/>.</para>
/// </devdoc>
public UniqueConstraint(String name, DataColumn column) {
DataColumn[] columns = new DataColumn[1];
columns[0] = column;
Create(name, columns);
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the specified <see cref='System.Data.DataColumn'/>.</para>
/// </devdoc>
public UniqueConstraint(DataColumn column) {
DataColumn[] columns = new DataColumn[1];
columns[0] = column;
Create(null, columns);
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the specified name and array
/// of <see cref='System.Data.DataColumn'/> objects.</para>
/// </devdoc>
public UniqueConstraint(String name, DataColumn[] columns) {
Create(name, columns);
}
/// <devdoc>
/// <para>
/// Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the given array of <see cref='System.Data.DataColumn'/>
/// objects.
/// </para>
/// </devdoc>
public UniqueConstraint(DataColumn[] columns) {
Create(null, columns);
}
// Construct design time object
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
[Browsable(false)]
public UniqueConstraint(String name, string[] columnNames, bool isPrimaryKey) {
this.constraintName = name;
this.columnNames = columnNames;
this.bPrimaryKey = isPrimaryKey;
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the specified name and
/// <see cref='System.Data.DataColumn'/>.</para>
/// </devdoc>
public UniqueConstraint(String name, DataColumn column, bool isPrimaryKey) {
DataColumn[] columns = new DataColumn[1];
columns[0] = column;
this.bPrimaryKey = isPrimaryKey;
Create(name, columns);
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the specified <see cref='System.Data.DataColumn'/>.</para>
/// </devdoc>
public UniqueConstraint(DataColumn column, bool isPrimaryKey) {
DataColumn[] columns = new DataColumn[1];
columns[0] = column;
this.bPrimaryKey = isPrimaryKey;
Create(null, columns);
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the specified name and array
/// of <see cref='System.Data.DataColumn'/> objects.</para>
/// </devdoc>
public UniqueConstraint(String name, DataColumn[] columns, bool isPrimaryKey) {
this.bPrimaryKey = isPrimaryKey;
Create(name, columns);
}
/// <devdoc>
/// <para>
/// Initializes a new instance of the <see cref='System.Data.UniqueConstraint'/> with the given array of <see cref='System.Data.DataColumn'/>
/// objects.
/// </para>
/// </devdoc>
public UniqueConstraint(DataColumn[] columns, bool isPrimaryKey) {
this.bPrimaryKey = isPrimaryKey;
Create(null, columns);
}
// design time serialization only
internal string[] ColumnNames {
get {
return key.GetColumnNames();
}
}
// VSTFDEVDIV 895693: please note that there are scenarios where ConstraintIndex is not the same as key.GetSortIndex()
// Use constraint index only for search operations (and use key.GetSortIndex() when enumeration is needed and/or order is important)
internal Index ConstraintIndex {
get {
AssertConstraintAndKeyIndexes();
return _constraintIndex;
}
}
[Conditional("DEBUG")]
private void AssertConstraintAndKeyIndexes() {
Debug.Assert(null != _constraintIndex, "null UniqueConstraint index");
// ideally, we would like constraintIndex and key.GetSortIndex to share the same index underneath: Debug.Assert(_constraintIndex == key.GetSortIndex)
// but, due to VSTFDEVDIV #895693 there is a scenario where constraint and key indexes are built from the same list of columns but in a different order
DataColumn[] sortIndexColumns = new DataColumn[_constraintIndex.IndexFields.Length];
for (int i = 0; i < sortIndexColumns.Length; i++) {
sortIndexColumns[i] = _constraintIndex.IndexFields[i].Column;
}
Debug.Assert(DataKey.ColumnsEqual(key.ColumnsReference, sortIndexColumns), "UniqueConstraint index columns do not match the key sort index");
}
internal void ConstraintIndexClear() {
if (null != _constraintIndex) {
_constraintIndex.RemoveRef();
_constraintIndex = null;
}
}
internal void ConstraintIndexInitialize() {
//Debug.Assert(null == _constraintIndex, "non-null UniqueConstraint index");
if (null == _constraintIndex) {
_constraintIndex = key.GetSortIndex();
_constraintIndex.AddRef();
}
AssertConstraintAndKeyIndexes();
}
internal override void CheckState() {
NonVirtualCheckState();
}
private void NonVirtualCheckState() {
key.CheckState();
}
internal override void CheckCanAddToCollection(ConstraintCollection constraints) {
}
internal override bool CanBeRemovedFromCollection(ConstraintCollection constraints, bool fThrowException) {
if (this.Equals(constraints.Table.primaryKey)) {
Debug.Assert(constraints.Table.primaryKey == this, "If the primary key and this are 'Equal', they should also be '=='");
if (!fThrowException)
return false;
else
throw ExceptionBuilder.RemovePrimaryKey(constraints.Table);
}
for (ParentForeignKeyConstraintEnumerator cs = new ParentForeignKeyConstraintEnumerator(Table.DataSet, Table); cs.GetNext();) {
ForeignKeyConstraint constraint = cs.GetForeignKeyConstraint();
if (!key.ColumnsEqual(constraint.ParentKey))
continue;
if (!fThrowException)
return false;
else
throw ExceptionBuilder.NeededForForeignKeyConstraint(this, constraint);
}
return true;
}
internal override bool CanEnableConstraint() {
if (Table.EnforceConstraints)
return ConstraintIndex.CheckUnique();
return true;
}
internal override bool IsConstraintViolated() {
bool result = false;
Index index = ConstraintIndex;
if (index.HasDuplicates) {
//
object[] uniqueKeys = index.GetUniqueKeyValues();
for (int i = 0; i < uniqueKeys.Length; i++) {
Range r = index.FindRecords((object[])uniqueKeys[i]);
if (1 < r.Count) {
DataRow[] rows = index.GetRows(r);
string error = ExceptionBuilder.UniqueConstraintViolationText(key.ColumnsReference, (object[])uniqueKeys[i]);
for (int j = 0; j < rows.Length; j++) {
//
rows[j].RowError = error;
foreach(DataColumn dataColumn in key.ColumnsReference){
rows[j].SetColumnError(dataColumn, error);
}
}
// SQLBU 20011224: set_RowError for all DataRow with a unique constraint violation
result = true;
}
}
}
return result;
}
internal override void CheckConstraint(DataRow row, DataRowAction action) {
if (Table.EnforceConstraints &&
(action == DataRowAction.Add ||
action == DataRowAction.Change ||
(action == DataRowAction.Rollback && row.tempRecord != -1))) {
if (row.HaveValuesChanged(ColumnsReference)) {
if (ConstraintIndex.IsKeyRecordInIndex(row.GetDefaultRecord())) {
object[] values = row.GetColumnValues(ColumnsReference);
throw ExceptionBuilder.ConstraintViolation(ColumnsReference, values);
}
}
}
}
internal override bool ContainsColumn(DataColumn column) {
return key.ContainsColumn(column);
}
internal override Constraint Clone(DataSet destination) {
return Clone(destination, false);
}
internal override Constraint Clone(DataSet destination, bool ignorNSforTableLookup) {
int iDest;
if (ignorNSforTableLookup) {
iDest = destination.Tables.IndexOf(Table.TableName);
}
else {
iDest = destination.Tables.IndexOf(Table.TableName, Table.Namespace, false);// pass false for last param to be backward compatable
}
if (iDest < 0)
return null;
DataTable table = destination.Tables[iDest];
int keys = ColumnsReference.Length;
DataColumn[] columns = new DataColumn[keys];
for (int i = 0; i < keys; i++) {
DataColumn src = ColumnsReference[i];
iDest = table.Columns.IndexOf(src.ColumnName);
if (iDest < 0)
return null;
columns[i] = table.Columns[iDest];
}
UniqueConstraint clone = new UniqueConstraint(ConstraintName, columns);
// ...Extended Properties
foreach(Object key in this.ExtendedProperties.Keys) {
clone.ExtendedProperties[key]=this.ExtendedProperties[key];
}
return clone;
}
internal UniqueConstraint Clone(DataTable table) {
int keys = ColumnsReference.Length;
DataColumn[] columns = new DataColumn[keys];
for (int i = 0; i < keys; i++) {
DataColumn src = ColumnsReference[i];
int iDest = table.Columns.IndexOf(src.ColumnName);
if (iDest < 0)
return null;
columns[i] = table.Columns[iDest];
}
UniqueConstraint clone = new UniqueConstraint(ConstraintName, columns);
// ...Extended Properties
foreach(Object key in this.ExtendedProperties.Keys) {
clone.ExtendedProperties[key]=this.ExtendedProperties[key];
}
return clone;
}
/// <devdoc>
/// <para>Gets the array of columns that this constraint affects.</para>
/// </devdoc>
[
ResCategoryAttribute(Res.DataCategory_Data),
ResDescriptionAttribute(Res.KeyConstraintColumnsDescr),
ReadOnly(true)
]
public virtual DataColumn[] Columns {
get {
return key.ToArray();
}
}
internal DataColumn[] ColumnsReference {
get {
return key.ColumnsReference;
}
}
/// <devdoc>
/// <para>Gets
/// a value indicating whether or not the constraint is on a primary key.</para>
/// </devdoc>
[
ResCategoryAttribute(Res.DataCategory_Data),
ResDescriptionAttribute(Res.KeyConstraintIsPrimaryKeyDescr)
]
public bool IsPrimaryKey {
get {
if (Table == null) {
return false;
}
return(this == Table.primaryKey);
}
}
private void Create(String constraintName, DataColumn[] columns) {
for (int i = 0; i < columns.Length; i++) {
if (columns[i].Computed) {
throw ExceptionBuilder.ExpressionInConstraint(columns[i]);
}
}
this.key = new DataKey(columns, true);
ConstraintName = constraintName;
NonVirtualCheckState();
}
/// <devdoc>
/// <para>Compares this constraint to a second to
/// determine if both are identical.</para>
/// </devdoc>
public override bool Equals(object key2) {
if (!(key2 is UniqueConstraint))
return false;
return Key.ColumnsEqual(((UniqueConstraint)key2).Key);
}
public override Int32 GetHashCode() {
return base.GetHashCode();
}
internal override bool InCollection {
set {
base.InCollection = value;
if (key.ColumnsReference.Length == 1) {
key.ColumnsReference[0].InternalUnique(value);
}
}
}
internal DataKey Key {
get {
return key;
}
}
/// <devdoc>
/// <para>Gets the table to which this constraint belongs.</para>
/// </devdoc>
[
ResCategoryAttribute(Res.DataCategory_Data),
ResDescriptionAttribute(Res.ConstraintTableDescr),
ReadOnly(true)
]
public override DataTable Table {
get {
if (key.HasValue) {
return key.Table;
}
return null;
}
}
// misc
}
}
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