Oracle学习笔记(五)

组合集总计: group by with rollup/cube grouping sets
子查询按执行方式分:标准子查询、关联子查询 标准子查询:嵌套子查询
标量值查询 case with then 使用exits查询 select user_id,user_name from
tb_001 tb where [not] exists (select ‘x’ from tb_001 where
manager_id=tb.user_id ) 关联更新 update table1 alias1 set
column=(select expression from table2 alias2 where
alias1.column=alias2.column); 关联删除 delete from table1 alias11 where
column operator (select expression from table2 alias2 where
alias1.column=alias2.column); 分层结构 分层检索 select
[level],column,expr… from table [where with condition(s)]
[connect by prior condition(s)] connect by prior column1=column2 top
down: colum1=parentkey column2=childkey bottom up: column1=childkey
column2=parentkey 插入语句insert statement insert into
table[(column[,column…])] values(value[,value…])
修改语句update statement update table set
column=value[,column=value,…] [where condition];
多表插入语句(Multitable Insert Statements) insert [all]
[conditional_insert_clause] [insert_into_cause
values_clause](subquery) conditional_insert_clause [all][first]
[when condition then][insert_into_clause values_clause]
[else][insert_into+clause values_clause] 列: intsert all into
tb_user values(id,uid,upwd) into tb_user_info values(id,name,sex,age)
select id,uid,upwd,name,sex,age from tb_u_10 where id10000;
待条件的多行插入 insert all when id11000 then into tb_user
values(id,uid,upwd) when age40 then into tb_user_info
values(id,name,sex,age) select id,uid,upwd,name,sex,age from tb_u_10
where id10000; insert first when conditional then into … when
conditional then into … else into… select… 创建索引 cretate table
t_10 (id number(6) not null primary key using index (create index
index1 on t_10(id)), name varchar2(50)); 查询索引 select * from
user_indexes;

相关文章

发表评论

电子邮件地址不会被公开。 必填项已用*标注

网站地图xml地图