返回一个最终记录

here is the table:

create table t1 (code varchar2(10), language varchar2(10),

dscr varchar2(10));

with this data:

insert into t1 values ('X','EN','english_dscr');

insert into t1 values ('X','FR','french_dscr');

how can i write a query or create a view to return the english record

when i do not in clude the language column in the where part of the query.

example.

select * from t1 where code='X';

to return the english record.

or

select * from t1 where code='X' and language='FR'

to return the french record.

thanks for your solution.

Unfortunately, it won't solve my problem.

i need to query, not based on my default language but on the language as

requested by the user who desires the info.

------------------------------------------------------------------------------------

You can use your "own" context as well via create context -- this uses the

default one that is there for all (but could be unreliable for the same reason

-- anything could change it) -- but shows the concept:

ops$tkyte@ORA9IR2 drop table t1;

Table dropped.

ops$tkyte@ORA9IR2

ops$tkyte@ORA9IR2

ops$tkyte@ORA9IR2 create table t1 (code varchar2(10), language varchar2(10),

2dscr varchar2(20));

Table created.

ops$tkyte@ORA9IR2

ops$tkyte@ORA9IR2 insert into t1 values ('X','EN','english_dscr');

1 row created.

ops$tkyte@ORA9IR2 insert into t1 values ('X','FR','french_dscr');

1 row created.

ops$tkyte@ORA9IR2

ops$tkyte@ORA9IR2 create or replace view v

2as

3select * from t1

4where language = case when sys_context( 'userenv', 'client_info') in (

'EN', 'FR' )

5then sys_context( 'userenv', 'client_info' )

6else 'EN'

7 end;

View created.

ops$tkyte@ORA9IR2

ops$tkyte@ORA9IR2 select * from v;

CODE LANGUAGE DSCR

---------- ---------- --------------------

XEN english_dscr

ops$tkyte@ORA9IR2 exec dbms_application_info.set_client_info( 'FR' );

PL/SQL procedure sUCcessfully completed.

ops$tkyte@ORA9IR2 select * from v;

CODE LANGUAGE DSCR

---------- ---------- --------------------

XFR french_dscr

ops$tkyte@ORA9IR2