private static void ReadIndexColumnData(DbDataReader reader, ref IndexReaderState state)
{
SqlExpression expression = null;
state.IndexName = reader.GetString(2).Trim();
if (state.IndexName != state.LastIndexName)
{
state.Table = state.Schema.Tables[reader.GetString(1).Trim()];
state.Index = state.Table.CreateIndex(state.IndexName);
state.Index.IsUnique = ReadBool(reader, 5);
state.Index.IsBitmap = false;
state.Index.IsClustered = false;
if (!reader.IsDBNull(8))
{
// expression index
expression = SqlDml.Native(reader.GetString(8).Trim());
}
}
if (expression == null)
{
var column = state.Table.TableColumns[reader.GetString(6).Trim()];
var isDescending = ReadBool(reader, 4);
_ = state.Index.CreateIndexColumn(column, !isDescending);
}
else
{
var isDescending = ReadBool(reader, 4);
_ = state.Index.CreateIndexColumn(expression, !isDescending);
}
state.LastIndexName = state.IndexName;
}
private void ExtractIndexes(Catalog catalog)
{
using var command = Connection.CreateCommand(GetExtractIndexesQuery());
using var reader = command.ExecuteReader(CommandBehavior.SingleResult);
var readerState = new IndexReaderState(catalog.DefaultSchema);
while (reader.Read())
{
ReadIndexColumnData(reader, ref readerState);
}
}
private async Task ExtractIndexesAsync(Catalog catalog, CancellationToken token)
{
var command = Connection.CreateCommand(GetExtractIndexesQuery());
await using (command.ConfigureAwait(false)) {
var reader = await command.ExecuteReaderAsync(CommandBehavior.SingleResult, token).ConfigureAwait(false);
await using (reader.ConfigureAwait(false)) {
var readerState = new IndexReaderState(catalog.DefaultSchema);
while (await reader.ReadAsync(token).ConfigureAwait(false))
{
ReadIndexColumnData(reader, ref readerState);
}
}
}
}
