SQL查询每天最新记录

发布于 2024-08-31 01:30:14 字数 793 浏览 8 评论 0原文

我有一个 Oracle 10g 数据库，其中有一个表，其结构和内容与以下内容非常相似：

CREATE TABLE MyTable
(
    id         INTEGER PRIMARY KEY,
    otherData  VARCHAR2(100),
    submitted  DATE
);

INSERT INTO MyTable VALUES (1, 'a', TO_DATE('28/04/2010 05:13', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (2, 'b', TO_DATE('28/04/2010 03:48', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (3, 'c', TO_DATE('29/04/2010 05:13', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (4, 'd', TO_DATE('29/04/2010 17:16', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (5, 'e', TO_DATE('29/04/2010 08:49', ''DD/MM/YYYY HH24:MI));

我需要做的是查询数据库以获取在每一天提交的最新记录。例如，对于上述数据，我希望返回 ID 号为 1 和 4 的记录，因为它们分别是 4 月 28 日和 4 月 29 日的最新记录。

不幸的是，我对 SQL 缺乏专业知识。有人可以提供一些关于如何实现这一目标的见解吗？

提前致谢！

原文

I've got an Oracle 10g database with a table with a structure and content very similar to the following:

CREATE TABLE MyTable
(
    id         INTEGER PRIMARY KEY,
    otherData  VARCHAR2(100),
    submitted  DATE
);

INSERT INTO MyTable VALUES (1, 'a', TO_DATE('28/04/2010 05:13', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (2, 'b', TO_DATE('28/04/2010 03:48', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (3, 'c', TO_DATE('29/04/2010 05:13', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (4, 'd', TO_DATE('29/04/2010 17:16', ''DD/MM/YYYY HH24:MI));
INSERT INTO MyTable VALUES (5, 'e', TO_DATE('29/04/2010 08:49', ''DD/MM/YYYY HH24:MI));

What I need to do is query the database for the latest record submitted on each given day. For example, with the above data I would expect the records with ID numbers 1 and 4 to be returned, as these are the latest each for 28 April and 29 April respectively.

Unfortunately, I have little expertise as far as SQL is concerned. Could anybody possibly provide some insight as to how to achieve this?

Thanks in advance!

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你列表最软的妹 2024-09-07 01:30:14

我会使用公共表表达式（又名 CTE），如下所示：

With RankedItems As
    (
    Select  Id, otherdata, submitted
        , ROW_NUMBER() OVER( PARTITION BY TO_CHAR(submitted, 'YYYY-MM-DD') ORDER BY submitted DESC ) ItemRank
    From MyTable
    )
Select
From RankedItems
Where ItemRank = 1

I would use a common table expression (aka CTE) like so:

With RankedItems As
    (
    Select  Id, otherdata, submitted
        , ROW_NUMBER() OVER( PARTITION BY TO_CHAR(submitted, 'YYYY-MM-DD') ORDER BY submitted DESC ) ItemRank
    From MyTable
    )
Select
From RankedItems
Where ItemRank = 1

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