A.惟一索引 B.惟一索引和候選索引 C.惟一索引和主索引 D.主索引和候選索引
A.標(biāo)簽 B.線條 C.矩形 D.圖片/ActiveX 綁定
A.SELECT 工資>1000 FROM 職工 B.SELECT SUM(工資) FROM 職工 WHERE 工資>1000 C.SELECT COUNT(*) FROM 職工 FOR 工資>1000 D.SELECT COUNT(*) FROM 職工 WHERE 工資>1000