分享：我的oracle9i学习笔记(三)

######### Managing Privileges ############# grant create table,create session to user_name; grant create any table to user_name; revoke create any table from user_name; /*授予权限语法,public 标识所有用户,with admin option答应能将权限授予第三者的权限*/ grant system_privs,[......] to [user/role/public],[....] [with admin option]; select * from v$pwfile_users; /*当 O7_dictionary_Accessiblity参数为True时，标识select any table时，包括系统表也能select ,否则，不包含系统表;缺省为false*/ show parameter O7; /*由于 O7_dictionary_accessiblity为静态参数，不能动态改变，故加scope=spfile,下次启动时才生效*/ alter system set O7_dictionary_accessiblity=true scope=spfile; /*授予对象中的某些字段的权限，如select 某表中的某些字段的权限*/ grant [object_privs(column,....)],[...] on object_name to user/role/public,... with grant option; /*Oracle不答应授予select某列的权限,但可以授insert ,update某列的权限*/ 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; /*db/os/none 审计被记录在 数据库/操作系统/不审计 缺省是none*/ show parameter audit_trail; /*启动对表的select动作*/ audit select on user.table_name by session; /*by session在每个session中发出command只记录一次，by access则每个command都记录*/ 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 /*取消审计*/ noaudit select on user.table_name; /*查被审计信息*/ select * from all_def_audit_opts/dba_stmt_audit_opts/dba_priv_audit_opts/dba_obj_audit_opts; /*获取审计记录*/ 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; /*建立default role,用户登录时，缺省激活default role*/ 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 /*使用字符函数(右边截取,字段中包含某个字符,左边填充某字符到固定位数,右边填充某字符到固定位数)*/ select substr(col1,-3,5),instr(col2,'g'),LPAD(col3,10,'$'),RPAD(col4,10,'%') from table_name; /*使用数字函数(往右/左几位四舍五入,取整,取余)*/ select round(col1,-2),trunc(col2),mod(col3) from table_name ; /*使用日期函数(计算两个日期间相差几个星期,两个日期间相隔几个月,在某个月份上加几个月,某个日期的下一个日期, 某日期所在月的最后的日期,对某个日期的月分四舍五入，对某个日期的月份进行取整)*/ 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; /*使用NULL函数(当eXPr1为空取expr2/当expr1为空取expr2,否则取expr3/当expr1=expr2返回空)*/ 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)] [LEFTRIGHTFULL 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 /*建立外键*/ 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 /*删除列，并级联删除此列下的约束条件*/ 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] [FORCENOFORCE] 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 /*使用别名*/ Create or replace view testview as select col1,sum(col2) col2_alias from table_name; /*创建复杂视图*/ 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; /*当用update修改数据时，必须满足视图的col1>;10的条件，不满足则不能被改变.*/ Create or replace view view_name as select * from table_name where col1>;10 with check option; /*改变视图的值.对于简单视图可以用update语法修改表数据，但复杂视图则不一定能改。如使用了函数，group by ,distinct等的列*/ update view_name set col1=value1; /*TOP-N分析*/ select [column_list],rownum from (select [column_list] from table_name order by Top-N_column) where rownum<=N; /*找出某列三条最大值的记录*/ 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 /*union 操作，它将两个集合的交集部分压缩，并对数据排序*/ select col1,col2,col3 from table1_name union select col1,col2,col3 from table2_name; /*union all 操作，两个集合的交集部分不压缩，且不对数据排序*/ select col1,col2,col3 from table1_name union all select col1,col2,col3 from table2_name; /*intersect 操作，求两个集合的交集,它将对重复数据进行压缩，且排序*/ select col1,col2,col3 from table1_name intersect select col1,col2,col3 from table2_name; /*minus 操作，集合减,它将压缩两个集合减后的重复记录, 且对数据排序*/ select col1,col2,col3 from table1_name minus select col1,col2,col3 from table2_name; /*EXTRACT 抽取时间函数. 此例是抽取当前日期中的年*/ select EXTRACT(YEAR FROM SYSDATE) from dual; /*EXTRACT 抽取时间函数. 此例是抽取当前日期中的月*/ 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: /*其结果看起来象对col1做小计*/ select col1,col2,sum(col3) from table group by rollup(col1,col2); /*复合rollup表达式*/ 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: /*其结果看起来象对col1做小计后，再对col2做小计，最后算总计*/ select col1,col2,sum(col3) from table group by cube(col1,col2); /*复合rollup表达式*/ select col1,col2,sum(col3) from table group by cube((col1,col2)); /*混合rollup,cube表达式*/ select col1,col2,col3,sum(col4) from table group by col1,rollup(col2),cube(col3); /*GROUPING(expr)函数，查看select语句种以何字段聚合，其取值为0或1*/ 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); /*grouping sets操作，对group by结果集先对col1求和，再对col2求和，最后将其结果集并在一起*/ select col1,col2,sum(col3) from table group by grouping sets((col1),(col2))