Oracle9i SQL 命令

  1. Alter 命令
  2. Create 命令
  3. Merge 命令
  4. SELECT 命令
  5. UPDATE 命令
  6. 数据透视

SQL 语句组成部分可用字符

项目 字符范围
字母(语法不区分大小写) A-Z
数字 0-9
字符 + - * = ? ! @ ( ) _ . , < > |
特别不推荐的字符 $ #

技巧:取前 N 条记录的查询语句:

SELECT [column_list], ROWNUM

FROM ( SELECT [column_list] FROM table ORDER BY column )

WHERE ROWNUM <= n;

用 SQL 语句实现分页

with dt as
( select 'b' as tc from dual
union
select 'a' as tc from dual
union
select 'd' as tc from dual
union
select 'c' as tc from dual
union
select 'e' as tc from dual
union
select 'f' as tc from dual
union
select 'g' as tc from dual
union
select 'h' as tc from dual
order by 1 )
select t2.* from
( select dt.*,rownum rn from dt ) t2
where rn>2 and rn<=4
order by rownum