/// <summary>
/// Permanently removes this column from the table.
/// </summary>
/// <remarks>
/// If there are dependencies on this column other than a primary key or a default, the operation may fail.
/// </remarks>
public void Remove()
{
// Remove the primary key if this column is in it
bool inPrimaryKey = this.ColumnInformation.Key;
ArrayList keyColumns = new ArrayList();
if (inPrimaryKey)
{
NativeMethods.IKeys keys = Table.dmoTable.GetKeys();
for (int i = 0; i < keys.GetCount(); i++)
{
// Find the primary key
if (keys.Item(i + 1).GetType() == NativeMethods.SQLDMO_KEY_TYPE.SQLDMOKey_Primary)
{
// First we have to keep a list of columns so we can undo the operation
NativeMethods.INames columnNames = keys.Item(i + 1).GetKeyColumns();
for (int j = 0; j < columnNames.GetCount(); j++)
{
keyColumns.Add(columnNames.Item(j + 1));
}
// Remove the primary key completely
// NOTE: This is what SQL Server Enterprise Manager does
keys.Remove(i + 1);
break;
}
}
}
// Remove default
string defaultValue = this.dmoColumn.GetDRIDefault().GetText();
this.dmoColumn.GetDRIDefault().Remove();
// Permanently delete this column
try {
dmoColumn.Remove();
}
catch {
// Undo operations and rethrow the exception
// Set default back
this.dmoColumn.GetDRIDefault().SetText(defaultValue);
// If necessary, create primary key and add original columns to it
if (inPrimaryKey)
{
NativeMethods.IKey primaryKey = (NativeMethods.IKey) new NativeMethods.Key();
primaryKey.SetType(NativeMethods.SQLDMO_KEY_TYPE.SQLDMOKey_Primary);
NativeMethods.INames columnNames = primaryKey.GetKeyColumns();
for (int i = 0; i < keyColumns.Count; i++)
{
columnNames.Add(columnInfo.Name);
}
table.dmoTable.GetKeys().Add(primaryKey);
}
throw;
}
}
