我需要列出所有的顾问对3000门课程和大学，主要为了我的升序排列结果

Question

SELECT program.prg_field AS "College" 
     , program.prg_name AS "Major" 
     , professor.pr_id AS "Professor ID" 
     , professor.pr_name AS "Advisor" 
     FROM professor 
INNER JOIN program ON program.prg_field = professor.pr_college 
    WHERE professor.pr_id LIKE '%3%' 
    ORDER BY "College" 
     , "Major" 
     ; 

我的问题，我想通过订购的pr_id列是这样的（例如：ACCT3332） ，我必须挑出第一个NUMBER并过滤掉只显示以3开头的数字的课程。

Answer 1

您可以使用REGEXP_LIKE而不是LIKE

SELECT program.prg_field AS "College" 
     , program.prg_name AS "Major" 
     , professor.pr_id AS "Professor ID" 
     , professor.pr_name AS "Advisor" 
     FROM professor 
INNER JOIN program ON program.prg_field = professor.pr_college 
    WHERE REGEXP_LIKE(professor.pr_id, '^\D+3') 
    ORDER BY "College" 
     , "Major" 
     ; 

如果pr_id的格式为4个字母字符，那么4位，那么你也可以这样做：

 WHERE SUBSTR(professor.pr_id, 5, 1) = '3') 

或（如由戈登·利诺夫建议）

 WHERE professor.pr_id LIKE '____3%' 

Answer 2

删除let先从pr_id列值开始。您有以下选择：

• 如果有一小部分可能的前缀码的REPLACE功能名称
• 的TRANSLATE功能，如果你知道字符在OCDE指定
的前缀使用性质
• REGEXP_REPLACE如果你什么都不知道，但有一个数字。

修改后的查询：

SELECT program.prg_field AS "College" 
     , program.prg_name AS "Major" 
     , professor.pr_id AS "Professor ID" 
     , professor.pr_name AS "Advisor" 
     FROM professor 
INNER JOIN program ON program.prg_field = professor.pr_college 
    WHERE TRANSLATE(UPPER(professor.pr_id), '1ABCDEFGHIJKLMNOPQRSTUVWXYZ', '1') LIKE '3%' 
    ORDER BY "College" 
     , "Major" 
     ; 

......或者......

 WHERE REPLACE(...REPLACE(professor.pr_id, 'ACCT'), ...) LIKE '3%' 

......或者......

 WHERE REGEXP_LIKE(professor.pr_id, '^[^0-9]*3')