SQL>show userUSER为"HR"SQL>SELECTfirst_name,last_name,department_id,2CASEdepartment_id3WHEN10THEN'Accounting'4WHEN20THEN'Sales'5WHEN30THEN'Finance'6ELSE'Other'7ENDdepartment_name8FROMemployees where rownum<2;FIRS
在Oracle SQL中,CASE表达式是一种条件表达式,用于根据不同的条件返回不同的结果。它可以在SELECT语句、WHERE子句、ORDER BY子句和其他SQL语句中使用。 CASE表达式有两种形式:简单CASE表达式和搜索CASE表达式。 简单CASE表达式: 简单CASE表达式使用固定的值进行比较,并根据每个值返回不同的结果。它的语法如下: ...
12 rows selected 与case when 配合: select case when grouping(e.department_id)=0 then ''||e.department_id else 'All Departments' end as department_id , case when grouping(e.job_id)=0 then e.job_id else 'All Jobs' end as job_id, avg(e.salary) from hr.employees e where e.depart...
GROUP BY ID ,NAME --2.2、Case方式 --这里使用max也可以,但是使用min和avg就不行了 SELECT ID,NAME, MAX(CASE WHEN course='语文' THEN score ELSE 0 END) 语文, MAX(CASE WHEN course='数学' THEN score ELSE 0 END) 数学, MAX(CASE WHEN course='英语' THEN score ELSE 0 END) 英语, MAX(CASE...
CASE表达式可以再SQL中实现if-then-else型的逻辑,9i及以上版本支持CASE表达式。 1. 使用简单CASE表达式 语法如下: CASE search_expression WHENexpression1 THEN result1 … ELSEdefault_result END store@PDB1> select product_id,product_type_id,caseproduct_type_id ...
SELECT*FROMlocationsWHEREcountry_idIN('US','CA','UK')ORDERBYcountry_id,CASEcountry_idWHEN'US'THENstateELSEcityEND;Code language:SQL (Structured Query Language)(sql) Try it In this example, the result set is sorted by the column state when the country is theUSand by the column city for...
6) 分析出来的内容查询 v$logmnr_content --sqlredo/sqlundo ### managing indexes ### /*create index*/ example: /*创建一般索引*/ create index index_name on table_name(column_name) tablespace tablespace_name; /*创建位图索引*/ create bitmap index...
For example, let’s extend the exam result to grade logic to also return: A* if the result is 100% U if the percentage is null or zero You can use a case expression like this: This enhancement is currently only in PL/SQL.
tCASE ttWHEN a < 3 THEN '小于3' ttELSE '大于等于3' tEND as b FROM t1; 也可以更加具体的比如: SELECT tCASE ttWHEN a = 1 THEN '等于1' ttWHEN a = 2 THEN '等于2' ttWHEN a > 2 THEN '大于2' tEND as b FROM t1; 总之,Case When是一种非常灵活的SQL语句,可以根据用户自定义的布尔...
case when是sql语句的语法,而不是属于特定数据库的语言 方法一: select num,name, (case classno when '1' then '一班' when '2' then '二班' else '其他班级' end) as classname from student 方法二: select num,name, (case when classno = '1' then '一班' ...