求每科前十名的学生用row_number和不用row_number的写法

好的，我来回答你的问题。

使用 row_number 的写法：

SELECT subject, name, score
FROM (
  SELECT subject, name, score, ROW_NUMBER() OVER (PARTITION BY subject ORDER BY score DESC) AS rank
  FROM scores
) AS t
WHERE rank <= 10;

不使用 row_number 的写法：

SELECT s1.subject, s1.name, s1.score
FROM scores s1
WHERE (
  SELECT COUNT(*)
  FROM scores s2
  WHERE s2.subject = s1.subject AND s2.score > s1.score
) < 10;

以上两种写法都可以得到每科前十名的学生。

相关问题

mysql5.7的row_number函数

在MySQL 5.7版本中，没有内置的ROW_NUMBER函数的写法。如果你需要实现类似ROW_NUMBER功能，可以使用变量和子查询来实现。以下是一种实现方式：

CREATE TABLE TZ_DIAG_STAND 
SELECT * 
FROM (
    SELECT 
        @RN := CASE WHEN @DIAGNOSIS_NAME = DIAGNOSIS_NAME THEN @RN + 1 ELSE 1 END AS RN,
        @DIAGNOSIS_NAME := DIAGNOSIS_NAME AS DIAG_NAME, 
        MASTER_ID, 
        NUM 
    FROM (
        SELECT 
            T1.DIAGNOSIS_NAME, 
            MASTER_ID, 
            COUNT(1) NUM 
        FROM (
            SELECT MASTER_ID, DIAGNOSIS_NAME 
            FROM ICD_10 
            WHERE MASTER_ID IS NOT NULL AND DIAGNOSIS_NAME = '妊娠合并肠炎'
        ) T1 
        GROUP BY T1.DIAGNOSIS_NAME, MASTER_ID 
        ORDER BY DIAGNOSIS_NAME, NUM DESC
    ) A, 
    (SELECT @RN := 0, @DIAGNOSIS_NAME := 0) B
) A 
WHERE RN = 1;

这个查询使用了变量@RN和@DIAGNOSIS_NAME来模拟ROW_NUMBER函数的功能，并在最外层的WHERE子句中选择RN等于1的记录。这样就可以获得诊断编码出现最多的记录。请注意，这只是一种实现方式，具体的查询语句可能会根据实际情况有所调整。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
- *1* *2* *3* [MySQL5.7版本没有row_number函数的写法](https://blog.csdn.net/qq_43278973/article/details/120205035)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT0_1"}}] [.reference_item style="max-width: 100%"]
[ .reference_list ]

select * row_number () over (partition by grid_longitude order by grid_latitude)as rn from wwx1249869.pr01_sulvjingzhengfenxi_no001__046098改为正确写法

根据你的描述，你想要将查询语句进行修改。正确的写法应该是：

SELECT *, ROW_NUMBER() OVER (PARTITION BY grid_longitude ORDER BY grid_latitude) AS rn
FROM wwx1249869.pr01_sulvjingzhengfenxi_no001__046098;

在这个修改后的查询语句中，我们使用 `SELECT *` 来选择所有列，然后使用 `ROW_NUMBER()` 函数来为每个 `grid_longitude` 分区中的行分配一个唯一的序号，并将其命名为 `rn`。最后，我们从表 `wwx1249869.pr01_sulvjingzhengfenxi_no001__046098` 中获取数据。