For solutions without WM_CONCAT in oraclexe
1. Download three files: owmctab.plb, owmaggrs.plb, owmaggrb.plb
2. Log in with sqlplus: sqlplus -logon sys/123 as sysdba
3. Execute @C:\Users\JOYTRAVEL\Desktop\WMSYS user\owmaggrb.plb;
If the execution result reports an error, saying that the WMSYS user cannot be found, then execute @C:\Users\JOYTRAVEL\Desktop\WMSYS user\owmctab.plb;
Execute owmaggrb and owmaggrs again