删除所有行一定数量后

Question

我有5000行数据。我想删除1000之后的所有行怎么做呢？

Delete from table
where *
limit 1000

这是正确的吗？

Answer 1

SQL Server

WITH cte
     AS (SELECT *,
                row_number() OVER (ORDER BY some_column) AS rn
         FROM   TABLE)
DELETE FROM cte
WHERE  rn > 1000 

Answer 2

DELETE FROM TABLE
WHERE ID NOT IN
(
   SELECT ID FROM TABLE LIMIT 1000
)

此查询将：

1 - 从数据库中选择THE FIRST 1000条记录

2 - 删除前100条记录列表中不存在的所有记录

Answer 3

SQL Fiddle

Oracle 11g R2架构设置：

CREATE TABLE test ( A ) AS
SELECT LEVEL
FROM   DUAL
CONNECT BY LEVEL <= 5000;

查询1 ：

SELECT COUNT(*) FROM test

<强> Results ：

| COUNT(*) |
|----------|
|     5000 |

查询2 ：

DELETE FROM test
WHERE A IN ( SELECT A FROM (SELECT A, ROWNUM rn FROM test ) WHERE rn > 1000 )

<强> Results ：

查询3 ：

SELECT COUNT(*) FROM test

<强> Results ：

| COUNT(*) |
|----------|
|     1000 |