[转载]oracle常用经典SQL查询
select t.tablespace_name,
round(sum(bytes/(1024*1024)),0)
ts_size
2、查看表空间物理文件的名称及大小
select tablespace_name,
file_id, file_name,round(bytes/(1024*1024),0)
total_space
3、查看回滚段名称及大小
select segment_name,
tablespace_name, r.status,(initial_extent/1024)
InitialExtent,(next_extent/1024) NextExtent,max_extents, v.curext
CurExtent
4、查看控制文件
select name from v$controlfile;
5、查看日志文件
select member from v$logfile;
6、查看表空间的使用情况
select
sum(bytes)/(1024*1024) as
free_space,tablespace_name
SELECT
A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES
FREE,(B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "%
FREE"
7、查看数据库库对象
select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status;
8、查看数据库的版本
Select version FROM
Product_component_version
9、查看数据库的创建日期和归档方式
Select Created, Log_Mode, Log_Mode From V$Database;
10、捕捉运行很久的SQL
column username format a12
column opname format a16
column progress format a8
select
username,sid,opname,round(sofar*100 / totalwork,0) || '%' as
progress,time_remaining,sql_text
11.查看数据表的参数信息
SELECT
12.查看还没提交的事务
select * from v$locked_object;
select * from v$transaction;
13.查找object为哪些进程所用
select
14。回滚段查看
select rownum, sys.dba_rollback_segs.segment_name Name, v$rollstat.extents
Extents, v$rollstat.rssize Size_in_Bytes, v$rollstat.xacts XActs,
v$rollstat.gets Gets, v$rollstat.waits Waits, v$rollstat.writes Writes,
sys.dba_rollback_segs.status status from v$rollstat, sys.dba_rollback_segs,
v$rollname where v$rollname.name(+) = sys.dba_rollback_segs.segment_name and
v$rollstat.usn (+) = v$rollname.usn order by rownum
15。耗资源的进程（top session）
select s.schemaname
schema_name,
to_char(command), 'Action
Code #' || to_char(command) )
action,
session_status,
nvl(s.username, '[Oracle
process]') user_name,
s.program
program,
where st.sid = s.sid
and
or s.status = 'ALL') and
p.addr = s.paddr order by st.value desc,
16。查看锁（lock）情况
select ls.osuser
os_user_name,
decode(ls.type, 'RW', 'Row wait enqueue lock', 'TM', 'DML enqueue lock', 'TX',
'Transaction enqueue lock',
'UL', 'User supplied lock')
lock_type,
o.object_name
object,
'Row Exclusive', 4, 'Share', 5, 'Share Row Exclusive', 6, 'Exclusive', null)
lock_mode,
from sys.dba_objects o,
(
l.lmode,
v$lock
l
<>
'SYS'
17。查看等待（wait）情况
SELECT v$waitstat.class, v$waitstat.count count, SUM(v$sysstat.value) sum_value
FROM v$waitstat, v$sysstat WHERE v$sysstat.name IN ('db block gets',
'consistent gets') group by v$waitstat.class, v$waitstat.count
18。查看sga情况
SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC
19。查看catched object
SELECT
owner,
20。查看V$SQLAREA
SELECT SQL_TEXT, SHARABLE_MEM, PERSISTENT_MEM, RUNTIME_MEM, SORTS,
VERSION_COUNT, LOADED_VERSIONS, OPEN_VERSIONS, USERS_OPENING, EXECUTIONS,
USERS_EXECUTING, LOADS, FIRST_LOAD_TIME, INVALIDATIONS, PARSE_CALLS, DISK_READS,
BUFFER_GETS, ROWS_PROCESSED FROM V$SQLAREA
21。查看object分类数量
select decode (o.type#,1,'INDEX' , 2,'TABLE' , 3 , 'CLUSTER' , 4, 'VIEW' , 5 ,
'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) object_type , count(*) quantity from
sys.obj$ o where o.type# > 1 group by decode (o.type#,1,'INDEX' , 2,'TABLE' , 3
, 'CLUSTER' , 4, 'VIEW' , 5 , 'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) union select
'COLUMN' , count(*) from sys.col$ union select 'DB LINK' , count(*) from
22。按用户查看object种类
select u.name
schema,
sum(decode(o.type#, 2, 1,
NULL)) tables,
clusters,
NULL))
synonyms,
sum(decode(o.type#, 1, NULL, 2, NULL, 3, NULL, 4, NULL, 5, NULL, 6, NULL, 1))
others
o.owner#
and
sys.link$ union select 'CONSTRAINT' , count(*) from sys.con$
23。有关connection的相关信息
1）查看有哪些用户连接
select s.osuser
os_user_name,
'Action Code #' ||
to_char(command) )
action,
status
session_status,
s.username
user_name,
0
memory,
from v$session
s,
order by s.username, s.osuser
2）根据v.sid查看对应连接的资源占用等情况
select n.name,
from
where v.sid = 71 and
order by n.class, n.statistic#
3）根据sid查看对应连接正在运行的sql
select
from v$sqlarea
where address = (select sql_address from v$session where sid = 71)
24．查询表空间使用情况
select a.tablespace_name "表空间名称",
100-round((nvl(b.bytes_free,0)/a.bytes_alloc)*100,2) "占用率(%)",
round(a.bytes_alloc/1024/1024,2) "容量(M)",
round(nvl(b.bytes_free,0)/1024/1024,2) "空闲(M)",
round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)",
Largest "最大扩展段(M)",
to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') "采样时间"
from
from dba_data_files f
group by tablespace_name) a,
(select
from dba_free_space f
group by tablespace_name) b,
(select round(max(ff.length)*16/1024,2) Largest,
from sys.fet$ ff, sys.file$ tf,sys.ts$ ts
where ts.ts#=ff.ts# and ff.file#=tf.relfile# and ts.ts#=tf.ts#
group by ts.name, tf.blocks) c
where a.tablespace_name = b.tablespace_name and a.tablespace_name = c.tablespace_name
25. 查询表空间的碎片程度
select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name
having count(tablespace_name)>10;
alter tablespace name coalesce;
alter table name deallocate unused;
create or replace view ts_blocks_v as
select tablespace_name,block_id,bytes,blocks,'free space' segment_name from dba_free_space
union all
select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents;
select * from ts_blocks_v;
select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space
group by tablespace_name;
26。查询有哪些数据库实例在运行
select inst_name from v$active_instances;
===========================================================
######### 创建数据库----look $ORACLE_HOME/rdbms/admin/buildall.sql #############
create database db01
maxlogfiles 10
maxdatafiles 1024
maxinstances 2
logfile
GROUP 1 ('/u01/oradata/db01/log_01_db01.rdo') SIZE 15M,
GROUP 2 ('/u01/oradata/db01/log_02_db01.rdo') SIZE 15M,
GROUP 3 ('/u01/oradata/db01/log_03_db01.rdo') SIZE 15M,
datafile 'u01/oradata/db01/system_01_db01.dbf') SIZE 100M,
undo tablespace UNDO
datafile '/u01/oradata/db01/undo_01_db01.dbf' SIZE 40M
default temporary tablespace TEMP
tempfile '/u01/oradata/db01/temp_01_db01.dbf' SIZE 20M
extent management local uniform size 128k
character set AL32UTE8
national character set AL16UTF16
set time_zone='America/New_York';
############### 数据字典##########
set wrap off
select * from v$dba_users;
grant select on table_name to user/rule;
select * from user_tables;
select * from all_tables;
select * from dba_tables;
revoke dba from user_name;
shutdown immediate
startup nomount
select * from v$instance;
select * from v$sga;
select * from v$tablespace;
alter session set nls_language=american;
alter database mount;
select * from v$database;
alter database open;
desc dictionary
select * from dict;
desc v$fixed_table;
select * from v$fixed_table;
set oracle_sid=foxconn
select * from dba_objects;
set serveroutput on
execute dbms_output.put_line('sfasd');
############# 控制文件###########
select * from v$database;
select * from v$tablespace;
select * from v$logfile;
select * from v$log;
select * from v$backup;
alter tablespace users begin backup;
select * from v$archived_log;
select * from v$controlfile;
alter system set control_files='$ORACLE_HOME/oradata/u01/ctrl01.ctl',
'$ORACLE_HOME/oradata/u01/ctrl02.ctl' scope=spfile;
cp $ORACLE_HOME/oradata/u01/ctrl01.ctl $ORACLE_HOME/oradata/u01/ctrl02.ctl
startup pfile='../initSID.ora'
select * from v$parameter where name like 'control%' ;
show parameter control;
select * from v$controlfile_record_section;
select * from v$tempfile;
alter database backup controlfile to '../filepath/control.bak';
alter database backup controlfile to trace;
############### redo log ##############
archive log list;
alter system archive log start;--启动自动存档
alter system switch logfile;--强行进行一次日志switch
alter system checkpoint;--强制进行一次checkpoint
alter tablspace users begin backup;
alter tablespace offline;
show parameter fast;
show parameter log_checkpoint;
alter database add logfile group 3 ('/$ORACLE_HOME/oracle/ora_log_file6.rdo' size 10M);
alter database add logfile member '/$ORACLE_HOME/oracle/ora_log_file6.rdo' to group 3;
alter database drop logfile group 3;
alter databse drop logfile member '$ORACLE_HOME/oracle/ora_log_file6.rdo';
alter database clear logfile '$ORACLE_HOME/oracle/ora_log_file6.rdo';
alter database clear logfile group 3;
alter database clear unarchived logfile group 3;
alter database rename file '$ORACLE_HOME/oracle/ora_log_file6.rdo' to '$ORACLE_HOME/oracle/ora_log_file6a.rdo';
show parameter db_create;
alter system set db_create_online_log_dest_1='path_name';
select * from v$log;
select * from v$logfile;
alter database noarchivelog/archivelog;
achive log start;---启动自动归档
alter system archive all;－－手工归档所有日志文件
select * from v$archived_log;
show parameter log_archive;
###### 分析日志文件logmnr ##############
1) 在init.ora中set utl_file_dir 参数
2) 重新启动oracle
3) create 目录文件
desc dbms_logmnr_d;
dbms_logmnr_d.build;
4) 加入日志文件 add/remove log file
dhms_logmnr.add_logfile
dbms_logmnr.removefile
5) start logmnr
dbms_logmnr.start_logmnr
6) 分析出来的内容查询 v$logmnr_content --sqlredo/sqlundo
实践：
desc dbms_logmnr_d;
update 表 set qty=10 where stor_id=6380;
delete 表 where stor_id=7066;
utl_file_dir的路径
execute dbms_logmnr_d.build('foxdict.ora','$ORACLE_HOME/oracle/admin/fox/cdump');
execute dbms_logmnr.add_logfile('$ORACLE_HOME/oracle/ora_log_file6.log',dbms_logmnr.newfile);
execute dbms_logmnr.start_logmnr(dictfilename=>'$ORACLE_HOME/oracle/admin/fox/cdump/foxdict.ora');
######### tablespace ##############
select * form v$tablespace;
select * from v$datafile;
select t1.name,t2.name from v$tablespace t1,v$datafile t2 where t1.ts#=t2.ts#;
alter tablespace users add datafile 'path' size 10M;
select * from dba_rollback_segs;
alter user user_name quota 10m on tablespace_name;
create tablespace xxx [datafile 'path_name/datafile_name'] [size xxx] [extent management local/dictionary] [default storage(xxx)];
exmple: create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M AUTOEXTEND ON NEXT 5M MAXSIZE 200M;
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management dictionary default storage(initial 100k next 100k pctincrease 10) offline;
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local uniform size 1m;
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local autoallocate;
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local uniform size 1m segment space management auto;
alter tablespace userdata mininum extent 10;
alter tablespace userdata default storage(initial 1m next 1m pctincrease 20);
create undo tablespace undo1 datafile '$ORACLE_HOME/oradata/undo101.dbf' size 40M extent management local;
show parameter undo;
create temporary tablespace userdata tempfile '$ORACLE_HOME/oradata/undo101.dbf' size 10m extent management local;
alter database default temporary tablespace tablespace_name;
alter tablespace tablespace_name offline/online;
alter tablespace tablespace_name read only;
alter tablespace tablespace_name rename datafile '$ORACLE_HOME/oradata/undo101.dbf' to '$ORACLE_HOME/oradata/undo102.dbf';
alter database rename file '$ORACLE_HOME/oradata/system01.dbf' to '$ORACLE_HOME/oradata/system02.dbf';
drop tablespace userdata including contents and datafiles;---drop tablespce
alter database datafile '$ORACLE_HOME/oradata/undo102.dbf' autoextend on next 10m maxsize 500M;
alter database datafile '$ORACLE_HOME/oradata/undo102.dbf' resize 50m;
alter tablespace userdata add datafile '$ORACLE_HOME/oradata/undo102.dbf' size 10m;
alter system set db_create_file_dest='$ORACLE_HOME/oradata';
create tablespace userdata;---use OMF status to create tablespace;
drop tablespace userdata;---user OMF status to drop tablespace;
select * from dba_tablespace/v$tablespace/dba_data_files;
alter table table_name move partition partition_name tablespace tablespace_name;
###### ORACLE storage structure and relationships #########
alter table kong.test12 allocate extent(size 1m datafile '$ORACLE_HOME/oradata/undo102.dbf');
alter table kong.test12 deallocate unused; ---释放表中没有用到的分区
show parameter db;
alter system set db_8k_cache_size=10m; ---配置8k块的内存空间块参数
select * from dba_extents/dba_segments/data_tablespace;
select * from dba_free_space/dba_data_file/data_tablespace;
select sum(bytes) from dba_extents where onwer='kong' and segment_name ='table_name';
############ UNDO Data ################
show parameter undo;
alter tablespace users offline normal;
alter tablespace users offline immediate;
recover datafile '$ORACLE_HOME/oradata/undo102.dbf';
alter tablespace users online ;
select * from dba_rollback_segs;
alter system set undo_tablespace=undotbs1;
alter system set undo_suppress_errors=true;
create rollback segment rbs1 tablespace undotbs;
desc dbms_flashback;
execute dbms_flashback.enable_at_time('26-JAN-04:12:17:00 pm');
execute dbms_flashback.disable;
select end_time,begin_time,undoblks from v$undostat;
select * from dba_rollback_segs/v$rollname/v$rollstat/v$undostat/v$session/v$transaction;
show parameter transactions;
show parameter rollback;
create public rollback segment prbs1 tablespace undotbs;
alter rollback segment rbs1 online;----在手工管理模式
########## Managing Tables ###########
select rowid,dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_row_number(rowid) from table_name;
create table test2
(
id int,
lname varchar2(20) not null,
fname varchar2(20) constraint ck_1 check(fname like 'k%'),
empdate date default sysdate)
) tablespace tablespace_name;
create global temporary table test2 on commit delete/preserve rows as select * from kong.authors;
create table user.table(...) tablespace tablespace_name storage(...) pctfree10 pctused 40;
alter table user.tablename pctfree 20 pctused 50 storage(...);---changing table storage
alter table user.table_name allocate extent(size 500k datafile '...');
alter table table_name deallocate unused;
alter table table_name deallocate unused keep 8k;
alter table user.table_name move tablespace new_tablespace_name;
create index index_name on user.table_name(column_name) tablespace users;
alter index index_name rebuild;
drop table table_name [CASCADE CONSTRAINTS];
alter table user.table_name drop column col_name [CASCADE CONSTRAINTS CHECKPOINT 1000];---drop column
alter table user.table_name set unused column comments CASCADE CONSTRAINTS;
alter table user.table_name drop unused columns checkpoint 1000;
ALTER TABLE USER.TABLE_NAME DROP COLUMNS CONTINUE CHECKPOINT 1000;
select * from dba_tables/dba_objects;
######## managing indexes ##########
example:
create index index_name on table_name(column_name) tablespace tablespace_name;
create bitmap index index_name on table_name(column_name1,column_name2) tablespace tablespace_name;
create [bitmap] index index_name on table_name(column_name) tablespace tablespace_name pctfree 20 storage(inital 100k next 100k) ;
create [bitmap] index index_name table_name(column_name1,column_name2) tablespace_name pctfree 20 storage(inital 100k next 100k) nologging;
create index index_name on table_name(column_name) reverse;
create index index_name on table_name(function_name(column_name)) tablespace tablespace_name;
create table user.table_name(column_name number(7) constraint constraint_name primary key deferrable using index storage(initial 100k next 100k) tablespace tablespace_name,column_name2 varchar2(25) constraint constraint_name not null,column_name3 number(7)) tablespace tablespace_name;
show parameter create_bit;
alter index index_name pctfree 30 storage(initial 200k next 200k);
alter index index_name allocate extent (size 200k datafile '$ORACLE/oradata/..');
alter index index_name deallocate unused;
alter index index_name rebuild tablespace tablespace_name;
alter index index_name rebuild tablespace tablespace_name reverse;
alter index index_name rebuild online;
alter index index_name COALESCE;
analyze index index_name validate structure;
desc index_state;
drop index index_name;
alter index index_name monitoring usage;-----监视索引是否被用到
alter index index_name nomonitoring usage;----取消监视
select * from dba_indexes/dba_ind_columns/dbs_ind_expressions/v$object_usage;
########## 数据完整性的管理(Maintaining data integrity) ##########
alter table table_name drop constraint constraint_name;----drop 约束
alter table table_name add constraint constraint_name primary key(column_name1,column_name2);-----创建主键
alter table table_name add constraint constraint_name unique(column_name1,column_name2);---创建唯一约束
alter table table_name add constraint constraint_name foreign key(column_name1) references table_name(column_name1);
alter table table_name add constraint constraint_name check(column_name like 'B%') enable/disable novalidate/validate;
alter table table_name modify constraint constraint_name initially deferred;
alter table table_name modify constraint constraint_name initially immediate;
alter session set constraints=deferred/immediate;
drop table table_name cascade constraints;
truncate table table_name;
alter table table_name disable constraint constraint_name;
alter table table_name enable novalidate constraint constraint_name;
alter table table_name add constraint constraint_name check(column_name >15) enable validate exceptions into exceptions;
start $ORACLE_HOME/rdbms/admin/utlexcpt.sql;
select * from user_constraints/dba_constraints/dba_cons_columns;
################## managing password security and resources ####################
alter user user_name account unlock/open;----锁定/打开用户;
alter user user_name password expire;---设定口令到期
create profile profile_name limit failed_login_attempts 3 password_lock_times 1/1440;
create profile profile_name limit failed_login_attempts 3 password_lock_time unlimited password_life_time 30 password_reuse_time 30 password_verify_function verify_function password_grace_time 5;
create profile prfile_name limit session_per_user 2 cpu_per_session 10000 idle_time 60 connect_time 480;
alter user user_name profile profile_name;
alter profile profile_name limit password_lock_time 1/24;
alter profile profile_name limit password_lift_time 2 password_grace_time 3;
alter profile profile_name limit password_reuse_time 10[password_reuse_max 3];
alter user user_name identified by input_password;-----修改用户口令
drop profile profile_name;
drop profile profile_name CASCADE;
alter system set resource_limit=true;---启用自愿限制,缺省是false
alter profile profile_name limit cpu_per_session 10000 connect_time 60 idle_time 5;
alter profile profile_name limit cpu_per_call 1000 logical_reads_per_call 10;
desc dbms_resouce_manager;---资源管理器包
select * from dba_users/dba_profiles;
###### Managing users ############
show parameter os;
create user testuser1 identified by kxf_001;
grant connect,createtable to testuser1;
alter user testuser1 quota 10m on tablespace_name;
create user user_name identified by password default tablespace tablespace_name temporary tablespace tablespace_name quota 15m on tablespace_name password expire;
alter database default temporary tablespace tablespace_name;
alter database default tablespace tablespace_name;
create user user_name identified by externally default OPS$tablespace_name tablespace_name temporary tablespace tablespace_name quota 15m on tablespace_name password expire;
alter user user_name quota 5m on tablespace_name;
drop user user_name [CASCADE];
desc dba_ts_quotas;select * from dba_ts_quotas where username='...';
alter user user_name default tablespace tablespace_name;
######### Managing Privileges #############
grant create table,create session to user_name;
grant create any table to user_name; revoke create any table from user_name;
grant system_privs,[......] to [user/role/public],[....] [with admin option];
select * from v$pwfile_users;
show parameter O7;
alter system set O7_dictionary_accessiblity=true scope=spfile;
grant [object_privs(column,....)],[...] on object_name to user/role/public,... with grant option;
grant insert(column_name1,column_name2,...) on table_name to user_name with grant option;
select * from dba_sys_privs/session_privs/dba_tab_privs/user_tab_privs/dba_col_privs/user_col_privs;
show parameter audit_trail;
audit select on user.table_name by session;
audit [create table][select/update/insert on object by session/access][whenever successful/not successful];
desc dbms_fga;---进一步设计，则可使用dbms_fgs包
noaudit select on user.table_name;
select * from all_def_audit_opts/dba_stmt_audit_opts/dba_priv_audit_opts/dba_obj_audit_opts;
select * from dba_audit_trail/dba_audit_exists/dba_audit_object/dba_audit_session/dba_audit_statement;
########### Managing Role #################
create role role_name; grant select on table_name to role_name; grant role_name to user_name; set role role_name;
create role role_name;
create role role_name identified by password;
create role role_name identified externally;
set role role_name ; ----激活role
set role role_name identified by password;
alter role role_name not identified;
alter role role_name identified by password;
alter role role_name identified externally;
grant priv_name to role_name [WITH ADMIN OPTION];
grant update(column_name1,col_name2,...) on table_name to role_name;
grant role_name1 to role_name2;
alter user user_name default role role_name1,role_name2,...;
alter user user_name default role all;
alter user user_name default role all except role_name1,...;
alter user user_name default role none;
set role role1 [identified by password],role2,....;
set role all;
set role except role1,role2,...;
set role none;
revoke role_name from user_name;
revoke role_name from public;
drop role role_name;
select * from dba_roles/dba_role_privs/role_role_privs/dba_sys_privs/role_sys_privs/role_tab_privs/session_roles;
########### Basic SQL SELECT ################
select col_name as col_alias from table_name ;
select col_name from table_name where col1 like '_o%'; ----'_'匹配单个字符
select substr(col1,-3,5),instr(col2,'g'),LPAD(col3,10,'$'),RPAD(col4,10,'%') from table_name;
select round(col1,-2),trunc(col2),mod(col3) from table_name ;
select (sysdate-col1)/7 week,months_between(sysdate,col1),add_months(col1,2),next_day(sysdate,'FRIDAY'),last_day(sysdate),
round(sysdate,'MONTH'),trunc(sysdate,'MONTH') from table_name;
select nvl(expr1,expr2),nvl2(expr1,expr2,expr3),nullif(expr1,expr2) from table_name;
select column1,column2,column3, case column2 when '50' then column2*1.1
when '30' then column2*2.1
when '10' then column3/20
else column3
end as ttt
from table_name ; ------使用case函数
select table1.col1,table2.col2 from table1
[CROSS JOIN table2] | -----笛卡儿连接
[NATURAL JOIN table2] | -----用两个表中的同名列连接
[JOIN table2 USING (column_name)] | -----用两个表中的同名列中的某一列或几列连接
[JOIN table2
ON (table1.col1=table2.col2)] |
[LEFT|RIGHT|FULL OUTER JOIN table2 ------相当于(+)=,=(+)连接,全外连接
ON (table1.col1=table2.col2)]; ------SQL 1999中的JOIN语法;
example:
select col1,col2 from table1 t1
join table2 t2
on t1.col1=t2.col2 and t1.col3=t2.col1
join table3 t3
on t2.col1=t3.col3;
select * from table_name where col1 < any (select col2 from table_name2 where continue group by col3);
select * from table_name where col1 < all (select col2 from table_name2 where continue group by col3);
insert into (select col1,col2,col3 form table_name where col1> 50 with check option) values (value1,value2,value3);
MERGE INTO table_name table1
USING table_name2 table2
ON (table1.col1=table2.col2)
WHEN MATCHED THEN
UPDATE SET
table1.col1=table2.col2,
table1.col2=table2.col3,
...
WHEN NOT MATCHED THEN
INSERT VALUES(table2.col1,table2.col2,table2.col3,...); -----合并语句
##################### CREATE/ALTER TABLE #######################
alter table table_name drop column column_name ;---drop column
alter table table_name set unused (col1,col2,...);----设置列无效，这个比较快。
alter table table_name drop unused columns;---删除被设为无效的列
rename table_name1 to table_name2; ---重命名表
comment on table table_name is 'comment message';----给表放入注释信息
create table table_name
(col1 int not null,col2 varchar2(20),col3 varchar2(20),
constraint uk_test2_1 unique(col2,col3))); -----定义表中的约束条件
alter table table_name add constraint pk_test2 primary key(col1,col2,...); ----创建主键
create table table_name (rid int,name varchar2(20),constraint fk_test3 foreign key(rid) references other_table_name(id));
alter table table_name add constraint ck_test3 check(name like 'K%');
alter table table_name drop constraint constraint_name;
alter table table_name drop primary key cascade;----级联删除主键
alter table table_name disable/enable constraint constraint_name;----使约束暂时无效
alter table table_name drop column column_name cascade constraint;
select * from user_constraints/user_cons_columns;---约束条件相关视图
############## Create Views #####################
CREATE [OR REPLACE] [FORCE|NOFORCE] VIEW view_name [(alias[,alias]...)]
AS subquery
[WITH CHECK OPTION [CONSTRAINT constraint_name]]
[WITH READ ONLY [CONSTRAINT constraint_name]]; ------创建视图的语法
example: Create or replace view testview as select col1,col2,col3 from table_name; ------创建视图
Create or replace view testview as select col1,sum(col2) col2_alias from table_name;
Create view view_name (alias1,alias2,alias3,alias4) as select d.col1,min(e.col1),max(e.col1),avg(e.col1) from table_name1 e,table_name2 d where e.col2=d.col2 group by d.col1;
Create or replace view view_name as select * from table_name where col1>10 with check option;
update view_name set col1=value1;
select [column_list],rownum from (select [column_list] from table_name order by Top-N_column) where rownum<=N;
example: select rownum as rank ,col1 ,col2 from (select col1 ,col2 from table_name order by col2 desc) where rownum<=3;
############# Other database Object ###############
CREATE SEQUENCE sequence_name [INCREMENT BY n]
[START WITH n]
[{MAXVALUE n | NOMAXVALUE}]
[{MINVALUE n | NOMINVALUE}]
[{CYCEL | NOCYCLE}]
[{CACHE n | NOCACHE}]; -----创建SEQUENCE
example:
CREATE SEQUENCE sequence_name INCREMENT BY 10
START WITH 120
MAXVALUE 9999
NOCACHE
NOCYCLE;
select * from user_sequences ;---当前用户下记录sequence的视图
select sequence_name.nextval,sequence_name.currval from dual;-----sequence的引用
alter sequence sequence_name INCREMENT BY 20
MAXVALUE 999999
NOCACHE
NOCYCLE; -----修改sequence,不能改变起始序号
drop sequence sequence_name; ----删除sequence
CREATE [PUBLIC] SYNONYM synonym_name FOR object; ------创建同义词
DROP [PUBLIC] SYNONYM synonym_name;----删除同义词
CREATE PUBLIC DATABASE LINK link_name USEING OBJECT;----创建DBLINK
select * from object_name@link_name; ----访问远程数据库中的对象
select col1,col2,col3 from table1_name union select col1,col2,col3 from table2_name;
select col1,col2,col3 from table1_name union all select col1,col2,col3 from table2_name;
select col1,col2,col3 from table1_name intersect select col1,col2,col3 from table2_name;
select col1,col2,col3 from table1_name minus select col1,col2,col3 from table2_name;
select EXTRACT(YEAR FROM SYSDATE) from dual;
select EXTRACT(MONTH FROM SYSDATE) from dual;
########################## 增强的 group by 子句 #########################
select [column,] group_function(column)...
from table
[WHERE condition]
[GROUP BY [ROLLUP] group_by_expression]
[HAVING having_expression];
[ORDER BY column]; -------ROLLUP操作字，对group by子句的各字段从右到左进行再聚合
example:
select col1,col2,sum(col3) from table group by rollup(col1,col2);
select col1,col2,sum(col3) from table group by rollup((col1,col2));
select [column,] group_function(column)...
from table
[WHERE condition]
[GROUP BY [CUBE] group_by_expression]
[HAVING having_expression];
[ORDER BY column]; -------CUBE操作字，除完成ROLLUP的功能外，再对ROLLUP后的结果集从右到左再聚合
example:
select col1,col2,sum(col3) from table group by cube(col1,col2);
select col1,col2,sum(col3) from table group by cube((col1,col2));
select col1,col2,col3,sum(col4) from table group by col1,rollup(col2),cube(col3);
select [column,] group_function(column)...,GROUPING(expr)
from table
[WHERE condition]
[GROUP BY [ROLLUP] group_by_expression]
[HAVING having_expression];
[ORDER BY column];
example:
select col1,col2,sum(col3),grouping(col1),grouping(col2) from table group by cube(col1,col2);
select col1,col2,sum(col3) from table group by grouping sets((col1),(col2));
