public static async Task <List <ColumnMetadata> > GetColumnMetadataAsync(this DatabaseMetadata md, String schemaNamePattern, String tableNamePattern, String columnNamePattern = null)
{
var list = new List <ColumnMetadata>();
await md.PrepareColumnSearch(schemaNamePattern, tableNamePattern, columnNamePattern).EnumerateAsync(async column => list.Add(await md.ExtractColumnAsync((SQLDataRow)column)));
return(list);
}