PostgreSQL中DELETE语句含ORDER BY报错：syntax error at or near 'order'

你执行的DELETE from Employee order by EmployeeID desc limit 3;会触发语法错误，因为PostgreSQL的DELETE语句不支持直接在主语句后追加ORDER BY和LIMIT子句。

要实现删除最后3行数据的需求，可以通过先筛选出目标行的主键，再执行删除的方式来完成，以下是两种可行写法：

方法一：子查询筛选目标ID #

DELETE FROM Employee
WHERE EmployeeID IN (
    SELECT EmployeeID
    FROM Employee
    ORDER BY EmployeeID DESC
    LIMIT 3
);

方法二：使用CTE（公共表表达式） #

WITH rows_to_delete AS (
    SELECT EmployeeID
    FROM Employee
    ORDER BY EmployeeID DESC
    LIMIT 3
)
DELETE FROM Employee
WHERE EmployeeID IN (SELECT EmployeeID FROM rows_to_delete);

这两种写法的核心逻辑一致：先通过查询获取最后3行的EmployeeID，再根据这些ID精准删除对应行，完全符合PostgreSQL的语法要求。

内容的提问来源于stack exchange，提问作者Nemiziz