【MySQL】细谈SQL高级查询

在MySQL中，进行SQL高级查询通常涉及子查询、JOIN操作、窗口函数（或称OLAP函数）等技术。以下是一些示例：

1. 子查询：

SELECT * FROM table1 WHERE column1 = (SELECT column1 FROM table2 WHERE condition);

2. JOIN操作：

SELECT * FROM table1 JOIN table2 ON table1.column1 = table2.column2;

3. 使用窗口函数（如ROW\_NUMBER()）进行分组排序：

SELECT * FROM (
    SELECT *, ROW_NUMBER() OVER (PARTITION BY column1 ORDER BY column2 DESC) AS rn
    FROM table1
) AS t
WHERE rn = 1;

4. 递归查询（CTE）：

WITH RECURSIVE cte (id, name, parent_id) AS (
    SELECT id, name, parent_id FROM table1 WHERE parent_id IS NULL
    UNION ALL
    SELECT t1.id, t1.name, t1.parent_id FROM table1 AS t1
    INNER JOIN cte ON t1.parent_id = cte.id
)
SELECT * FROM cte;

这些示例展示了如何在MySQL中执行不同类型的高级查询操作。实际使用时，需要根据具体的数据库结构和查询需求来调整SQL语句。