【文件属性】：
文件名称：数据查询-数据库培训
文件大小：2.01MB
文件格式：PPT
更新时间：2024-05-15 13:24:23
数据库
数据查询
SELECT [ ALL ｜ DISTINCT ] < select_expr1[,< select_expr2[,…]
FROM < table_name1>,< table_name2>[，…]
[WHERE ]
[GROUP BY [HAVING]]
[ORDER BY [ASC ｜ DESC]]
EXAMPLE
SELECT *
FROM employees
WHERE department_id = 30
ORDER BY last_name;
2. SELECT last_name, job_id, salary, department_id
FROM employees
WHERE NOT (job_id = 'PU_CLERK' AND department_id = 30)
ORDER BY last_name;
3. SELECT department_id, MIN(salary), MAX (salary)
FROM employees
GROUP BY department_id
ORDER BY department_id;
