PERCENT --a.id, THEN c.name ELSE '' END AS 表名, THEN a.name ELSE '' END AS 索引名称, d.name AS 列名, b.keyno AS 索引顺序, CASE indexkey_property(c.id, b.indid, b.keyno, 'isdescending') THEN '升序' END AS 排序, CASE WHEN p.id IS NULL THEN '' ELSE '√' END AS 主键, CASE