sql - SELECT ALL records FROM each TABLE ORDER BY PRIMARY KEYS(EID,CID,FID,EnID) 降序

Question

需要一条 SQL 语句从每个表 ORDER BY 主键中按降序选择所有记录。

这没有给出完整的陈述

SELECT table_name, num_rows counter FROM user_tables;

我已经尝试过：

SELECT table_name, num_rows counter FROM user_tables;

我希望按降序列出所有 4 个表的输出 ORDER BY EID、CID、FID 和 ENID，它们是主键

标签： sqloracle

Answer 1

您可以为此使用联合...

SELECT EID AS ID, 'Engineers' AS TableName FROM Engineers
UNION
SELECT SID, 'Staff' FROM Staff
UNION
SELECT FID, 'Classes' FROM Classes
UNION
SELECT ENID, 'StudentEnrollments' FROM StudentEnrollments
ORDER BY 1

在这种情况下，“ORDER BY 1”表示第一列。