还有一种可能性是在SQLPLUS或者其他IDE(例如PL/SQL DEVELOPER下)存在&(AND)符号时，客户端将&理解为变量，如： SQL> create user maclean_password1 identified by "0000&a"; Enter value for a: 此时只需要将define修改为非&的其他符号即可，例如：

SQL> set define +

SQL> show define define "+" (hex 2b)

SQL> create user maclean_password1 identified by "0000&a"; User created.

SQL> grant connect to maclean_password1;

Grant succeeded.

SQL> conn maclean_password1/"0000&a" Connected.

SQL> set define +
SQL> set define +
SP2-0317: expected symbol name is missing
SQL> alter user rick identified by "Ods&Report_2022";

User altered.

SQL> show define;
define "+" (hex 2b)
SQL> set define +
SP2-0317: expected symbol name is missing
SQL> set define +
SP2-0317: expected symbol name is missing
SQL> set define .
SQL>