PLSQL里能使用DECODE语句吗答:BEGIN n:=DECODE(1,2,3,4,5);END;/ n:=DECODE(1,2,3,4,5);ERROR at line 4:ORA-06550: line 4, column 5:PLS-00204: function or pseudo-column 'DECODE' may be used inside a SQL statement only ORA-06550: line 4, column 2:PL/SQL: Statement ignored 但是放到select语句里...