s02过滤和排序数据

1、2Copyright Oracle Corporation, 2001. All rights reserved.S02 过滤和排序数据过滤和排序数据 2-2Copyright Oracle Corporation, 2001. All rights reserved.目标目标通过本章学习，您将可以通过本章学习，您将可以:在查询中过滤行。在查询中过滤行。在查询中对行进行排序。在查询中对行进行排序。2-3Copyright Oracle Corporation, 2001. All rights reserved.在查询中过滤行在查询中过滤行返回在返回在 90好部门工好部门工作的所有员工的信作的

2、所有员工的信息息EMPLOYEES2-4Copyright Oracle Corporation, 2001. All rights reserved.过滤过滤使用使用WHERE 子句，将不满足条件的行过滤掉。子句，将不满足条件的行过滤掉。WHERE 子句紧随子句紧随 FROM 子句。子句。SELECT*|DISTINCT column|expression alias,.FROMtableWHEREcondition(s);2-5Copyright Oracle Corporation, 2001. All rights reserved.WHERE 子句子句SELECT employee_

3、id, last_name, job_id, department_idFROM employeesWHERE department_id = 90 ;2-6Copyright Oracle Corporation, 2001. All rights reserved.字符和日期字符和日期字符和日期要包含在单引号中。字符和日期要包含在单引号中。字符大小写敏感，日期格式敏感。字符大小写敏感，日期格式敏感。默认的日期格式是默认的日期格式是 DD-MON-RR。SELECT last_name, job_id, department_idFROM employeesWHERE last_name =

4、 Whalen;2-7Copyright Oracle Corporation, 2001. All rights reserved.比较运算比较运算操作符操作符= = =含义含义等于等于大于大于 大于、等于大于、等于 小于小于 小于、等于小于、等于不等于不等于2-8Copyright Oracle Corporation, 2001. All rights reserved.SELECT last_name, salaryFROM employeesWHERE salary =10000AND job_id LIKE %MAN%;2-17Copyright Oracle Corporatio

5、n, 2001. All rights reserved.OROR 要求或关系为真。要求或关系为真。SELECT employee_id, last_name, job_id, salaryFROM employeesWHERE salary = 10000OR job_id LIKE %MAN%;2-18Copyright Oracle Corporation, 2001. All rights reserved.SELECT last_name, job_idFROM employeesWHERE job_id NOT IN (IT_PROG, ST_CLERK, SA_REP);NOT2

6、-19Copyright Oracle Corporation, 2001. All rights reserved.优先级优先级可以使用括号改变优先级顺序可以使用括号改变优先级顺序 优先级优先级 1算术运算符算术运算符2连接符连接符3比较符比较符4IS NOT NULL, LIKE, NOT IN5NOT BETWEEN6NOT 7AND8OR2-20Copyright Oracle Corporation, 2001. All rights reserved.SELECT last_name, job_id, salaryFROM employeesWHERE job_id = SA_RE

7、POR job_id = AD_PRESAND salary 15000;优先级优先级2-21Copyright Oracle Corporation, 2001. All rights reserved.SELECT last_name, job_id, salaryFROM employeesWHERE (job_id = SA_REPOR job_id = AD_PRES)AND salary 15000;优先级优先级使用括号控制执行顺序。使用括号控制执行顺序。2-22Copyright Oracle Corporation, 2001. All rights reserved.SELE

8、CT last_name, job_id, department_id, hire_dateFROM employeesORDER BY hire_date ;ORDER BY子句子句使用使用 ORDER BY 子句排序子句排序ASC: 升序升序DESC: 降序降序ORDER BY 子句在子句在SELECT语句的结尾。语句的结尾。2-23Copyright Oracle Corporation, 2001. All rights reserved.降序排序降序排序SELECT last_name, job_id, department_id, hire_dateFROM employeesOR

9、DER BY hire_date DESC ;2-24Copyright Oracle Corporation, 2001. All rights reserved.按别名排序按别名排序SELECT employee_id, last_name, salary*12 annsalFROM employeesORDER BY annsal;2-25Copyright Oracle Corporation, 2001. All rights reserved.按照按照ORDER BY 列表的顺序排序。列表的顺序排序。可以使用不在可以使用不在SELECT 列表中的列排序。列表中的列排序。SELECT last_name, department_id, salaryFROM employeesORDER BY department_id, salary DESC;多个列排序多个列排序2-26Copyright Oracle Corporation, 2001. All rights reserved.总结总结SELECT *|DISTINCT column|expression alias,.FROM tableWHERE condition(s)ORDER BY column, expr, alias ASC