Oracle學習筆記 五

2022-09-24 20:48:14 字數 2413 閱讀 4551

組合集總計:

group by with rollup/cube

grouping sets

子查詢按執行方式分:標準子查詢、關聯子查詢

標準子查詢:巢狀子查詢

標量值查詢

case with then

使用exits查詢

select user_id,user_name from tb_001 tb

where [not] exists (select 'x'

from tb_001

where manager_id=tb.user_id )

關聯更新

update table1 alias1

set column=(select expression

from table2 alias2

where alias1.column=alias2.column);

關聯刪除

d from table1 alias11

where column operator

(select expression

from table2 alias2

where alias1.column=alias2.column);

分層結構

分層檢索

select [level],column,expr...

from table

[where with condition(s)]

[connect by prior condition(s)]

connect by prior column1=column2

top dwww.cppcns.comown:

colum1=parentkey

column2=childkey

bottom up:

column1=childkey

column2=parentkey

插入語句insert statement

insert into table[(column[,column...])]

values(value[,value...])

修改語句update statement

update table

set column=value[,column=value,...]

[ condition];

多表插入語句(multitable insert statements)

insert [all] [conditional_insert_clause]

[insert_into_cause values_claus程式設計客棧e](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,***,age)

select id,uid,upwd,name,***,age

from tb_u_10

where id>10000;

待條件的多行插入

insert all

when id>11000 then

into tb_user values(id,uid,upyzoewwd)

when age>40 then

into tb_user_info values(id,name,***,age)

select id,uid,upwd,name,***,age

from tb_u_10

where id>10000;

insert first

when conditional then

into ...

when conditional then

into ...

else

into...

select...

建立索引

cretate table t_10

(id number(6) not null primary key using index (create index index1 on t_10(id)),

name varchar2(50));

查詢索引

select * from user_indexes;

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