数据库DQL

-- 基本查询
SELECT column1, column2, ..., columnN
FROM table_name;

-- 条件查询
SELECT column1, column2, ..., columnN
FROM table_name
WHERE condition;

-- 分组查询
SELECT column1, column2, ..., columnN, aggregate_function(column)
FROM table_name
GROUP BY column1, column2, ...;

-- 分组后的条件查询
SELECT column1, column2, ..., columnN, aggregate_function(column)
FROM table_name
GROUP BY column1, column2, ...
HAVING condition;

-- 排序查询
SELECT column1, column2, ..., columnN
FROM table_name
ORDER BY column1 [ASC|DESC], column2 [ASC|DESC], ...;

-- 限制返回行数
SELECT column1, column2, ..., columnN
FROM table_name
LIMIT number;

-- 偏移返回行数
SELECT column1, column2, ..., columnN
FROM table_name
OFFSET number;

-- 综合示例
SELECT column1, column2, ..., columnN, aggregate_function(column)
FROM table_name
WHERE condition
GROUP BY column1, column2, ...
HAVING condition
ORDER BY column1 [ASC|DESC], column2 [ASC|DESC], ...
LIMIT number
OFFSET number;