Unique

bool System.Data.DataColumn.Unique

getset

Definition at line 875 of file DataColumn.cs.

    {
        get
        {
            return _unique;
        }
        set
        {
            long scopeId = DataCommonEventSource.Log.EnterScope("<ds.DataColumn.set_Unique|API> {0}, {1}", ObjectID, value);
            try
            {
                if (_unique == value)
                {
                    return;
                }
                if (value && _expression != null)
                {
                    throw ExceptionBuilder.UniqueAndExpression();
                }
                UniqueConstraint constraint = null;
                if (_table != null)
                {
                    if (value)
                    {
                        CheckUnique();
                    }
                    else
                    {
                        IEnumerator enumerator = _table.Constraints.GetEnumerator();
                        while (enumerator.MoveNext())
                        {
                            if (enumerator.Current is UniqueConstraint uniqueConstraint && uniqueConstraint.ColumnsReference.Length == 1 && uniqueConstraint.ColumnsReference[0] == this)
                            {
                                constraint = uniqueConstraint;
                            }
                        }
                        _table.Constraints.CanRemove(constraint, fThrowException: true);
                    }
                }
                _unique = value;
                if (_table != null)
                {
                    if (value)
                    {
                        UniqueConstraint constraint2 = new UniqueConstraint(this);
                        _table.Constraints.Add(constraint2);
                    }
                    else
                    {
                        _table.Constraints.Remove(constraint);
                    }
                }
            }
            finally
            {
                DataCommonEventSource.Log.ExitScope(scopeId);
            }
        }
    }

Referenced by System.Data.DataTableReader.GetSchemaTableFromDataTable(), System.Data.DataColumn.SetOrdinalInternal(), and System.Data.DataColumn.SetTable().