public void Execute(DatabaseTable baseTable, DatabaseTable compareTable)
{
//find new columns (in compare, but not in base)
foreach (var column in compareTable.Columns)
{
var name = column.Name;
var match = baseTable.Columns.FirstOrDefault(t => t.Name == name);
if (match != null)
{
continue;
}
var script = "-- ADDED TABLE " + column.TableName + " COLUMN " + name + Environment.NewLine +
_writer.AddColumn(compareTable, column);
CreateResult(ResultType.Add, baseTable, name, script);
}
//find dropped and existing columns
foreach (var column in baseTable.Columns)
{
var name = column.Name;
var match = compareTable.Columns.FirstOrDefault(t => t.Name == name);
if (match == null)
{
CreateResult(ResultType.Delete, baseTable, name,
_writer.DropColumn(baseTable, column));
continue;
}
//has column changed?
if (string.Equals(column.DbDataType, match.DbDataType, StringComparison.OrdinalIgnoreCase) &&
column.Length == match.Length &&
column.Precision == match.Precision &&
column.Scale == match.Scale &&
column.Nullable == match.Nullable)
{
//we don't check IDENTITY
continue; //the same, no action
}
CreateResult(ResultType.Change, baseTable, name,
_writer.AlterColumn(baseTable, match, column));
}
}