deptno||'' d number + varchar=varcharSQL> select dump(1) from dual;DUMP(1)------------------Typ=2 Len=2: 193,2SQL> select dump(1||'') from dual;DUMP(1||'')---------------Typ=1 Len=1: 49
显示全部deptno||'' d number + varchar=varchar
SQL> select dump(1) from dual;
DUMP(1)
------------------
Typ=2 Len=2: 193,2
SQL> select dump(1||'') from dual;
DUMP(1||'')
---------------
Typ=1 Len=1: 49
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