public override void Perform(SchemaChanges changes, IOutput output)
{
foreach (var pending in PendingReorderTableType.AllFrom(changes.Current))
{
var originalTable = TableType.Identifier(pending.Name);
var tempTable = pending.ParentIdentifier;
if (object.Equals(originalTable, tempTable))
{
// If the database fails at precisely the wrong time, the rename can be succeed without dropping the PendingReorder,
// so the table thinks it's to be renamed to itself. In that case we need to drop the PendingReorder, NOT drop the table!
output.Verbose("Cleaning up after completed reorder of columns in " + originalTable);
changes.Remove(null, pending);
}
else if (changes.Current.ContainsRoot(originalTable))
{
// If the original table still exists, we drop the temp table so we can start over (in case the data in the table has changed since the temp table
// was created, or the reordering has somehow become unnecessary).
output.Verbose("Clearing pending reorder of columns in " + originalTable);
changes.Remove(changes.SchemaDriver.GetDropTableSql(pending.ParentName), changes.Current.GetRoot(pending.ParentIdentifier));
}
else
{
// The original table has been dropped so we need to recreate it by renaming the temp table.
output.Verbose("Completing pending reordering of columns in " + originalTable);
changes.Rename(changes.SchemaDriver.GetRenameTableSql(tempTable.Name, originalTable.Name), tempTable, originalTable);
// And forget about the pending rename.
changes.Remove(null, pending.WithParent(originalTable));
}
}
}
private void renameTempTables(SchemaChanges changes, IOutput output)
{
// For any PendingReorderTables where the original table doesn't exist, rename the table to the target name and remove the pending rename.
foreach (var pending in PendingReorderTableType.AllFrom(changes.Current))
{
var originalTable = TableType.Identifier(pending.Name);
var tempTable = pending.ParentIdentifier;
if (changes.Current.ContainsRoot(originalTable))
{
continue;
}
changes.Rename(changes.SchemaDriver.GetRenameTableSql(tempTable.Name, originalTable.Name), tempTable, originalTable);
changes.Remove(null, pending.WithParent(originalTable));
}
}
public override void Perform(SchemaChanges changes, IOutput output)
{
var renames = from rename in TableRenameType.AllFrom(changes.Desired)
where changes.Current.ContainsRoot(TableType.Identifier(rename.Name))
group rename by rename.State.ToTable into destination
select destination;
foreach (var rename in renames)
{
var toTable = rename.Key;
if (rename.Count() > 1)
{
changes.Fail("Rename conflict: Multiple tables (" + string.Join(", ", from source in rename select source.Name) + ") wish to be renamed to " + toTable.Name);
continue;
}
var fromTable = TableType.Identifier(rename.Single().Name);
if (changes.Current.ContainsRoot(toTable))
{
changes.Fail("Rename conflict: " + fromTable + " wishes to be renamed to " + rename.Key.Name + ", but that table already exists.");
continue;
}
if (changes.Desired.ContainsRoot(fromTable))
{
changes.Fail("Rename conflict: " + fromTable + " wishes to be renamed to " + rename.Key.Name + " but also to continue existing with its current name.");
continue;
}
if (!changes.Desired.ContainsRoot(toTable))
{
changes.Fail("Rename conflict: " + fromTable + " wishes to be renamed to " + rename.Key.Name + " but that table is not supposed to exist.");
continue;
}
changes.Rename(changes.SchemaDriver.GetRenameTableSql(fromTable.Name, toTable.Name), fromTable, toTable);
}
}