어떻게 Oracle 의 Decode 함 수 를 사용 하여 다 중 값 판단 을 합 니까?

decode (expression, search_1, result_1)

decode (expression, search_1, result_1, search_2, result_2)

decode (expression, search_1, result_1, search_2, result_2, ...., search_n, result_n)



decode (expression, search_1, result_1, default)

decode (expression, search_1, result_1, search_2, result_2, default)

decode (expression, search_1, result_1, search_2, result_2, ...., search_n, result_n, default)

SQL> create table t as select username,default_tablespace,lock_date from dba_users;



Table created.



SQL> select * from t;



USERNAME                       DEFAULT_TABLESPACE             LOCK_DATE

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

SYS                            SYSTEM

SYSTEM                         SYSTEM

OUTLN                          SYSTEM

CSMIG                          SYSTEM

SCOTT                          SYSTEM

EYGLE                          USERS

DBSNMP                         SYSTEM

WMSYS                          SYSTEM                         20-OCT-04



8 rows selected.





SQL> select username,decode(lock_date,null,'unlocked','locked') status from t;



USERNAME                       STATUS

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

SYS                            unlocked

SYSTEM                         unlocked

OUTLN                          unlocked

CSMIG                          unlocked

SCOTT                          unlocked

EYGLE                          unlocked

DBSNMP                         unlocked

WMSYS                          locked



8 rows selected.



SQL> select username,decode(lock_date,null,'unlocked') status from t;



USERNAME                       STATUS

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

SYS                            unlocked

SYSTEM                         unlocked

OUTLN                          unlocked

CSMIG                          unlocked

SCOTT                          unlocked

EYGLE                          unlocked

DBSNMP                         unlocked

WMSYS



8 rows selected.