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.