Question

ORA-30004 when using SYS_CONNECT_BY_PATH function, cannot have seperator as part of the column

Action: Use another seperator which does not occur in any column
value, then retry.

Error on:

select ...
Sys_Connect_By_Path(myVariable || ':' || mySecondVariable, ' --> ') "myNewVar",
...

Works:

select ...
Sys_Connect_By_Path(myVariable || ':' || mySecondVariable, ' -> ') "myNewVar",
...

In the data we found some text like this

• SomeText B--More Text
• SomeText A--More Text

Since there is no '-->' or for that mater no ‘-->‘ in the data why does the first one error? The second one has a space in front and on the end.

Answer 1

Thats because -- is a part of --> separator but not a part of -> separator.

Even if your data value has --> this query should not error. Like below.

SQL> select Sys_Connect_By_Path('SomeText B-->More Text' || ':' || 'SomeText A-->More Text', ' --> ') "myNewVar"
from dual
connect by  rownum<=3;

myNewVar                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
----------------------------------------------------
--> SomeText B-->More Text:SomeText A-->More Text                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
--> SomeText B-->More Text:SomeText A-->More Text --> SomeText B-->More Text:SomeText A-->More Text                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
--> SomeText B-->More Text:SomeText A-->More Text --> SomeText B-->More Text:SomeText A-->More Text --> SomeText B-->More Text:SomeText A-->More Text

The separator above is -->, notice the whitespace. This whitespace is considered as part of the separator i.e. chr(1)||chr(45)||chr(45)||chr(62)||chr(1). This entire string is not a part of your data or column value.

Where as below would error

SQL> select Sys_Connect_By_Path('SomeText B-->More Text' || ':' || 'SomeText A-->More Text', '-->') "myNewVar"
from dual
connect by  rownum<=3;

ORA-30004: when using SYS_CONNECT_BY_PATH function, cannot have seperator as part of column value
30004. 00000 -  "when using SYS_CONNECT_BY_PATH function, cannot have seperator as part of column value"
*Cause:    
*Action:   Use another seperator which does not occur in any column value,
           then retry.

The separator above is -->, notice there is no whitespace i.e. chr(45)||chr(45)||chr(62). This entire string is indeed a part of your data or column value and hence the error.

And here’s a solution (performance un-tested)

select regexp_replace(Sys_Connect_By_Path('SomeText B-->More Text' || ':' || 'SomeText A-->More Text', ' -> '),' -> ','-->') "myNewVar"
from dual
connect by  rownum<=3;

myNewVar                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
--------------------------------------
-->SomeText B-->More Text:SomeText A-->More Text                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
-->SomeText B-->More Text:SomeText A-->More Text-->SomeText B-->More Text:SomeText A-->More Text                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
-->SomeText B-->More Text:SomeText A-->More Text-->SomeText B-->More Text:SomeText A-->More Text-->SomeText B-->More Text:SomeText A-->More Text 

Explanation – Here(in the query above) -> (with space) is not part of the data here i.e. -->. Once the column is conected by path the regexp_replace replaces all occurences of -> with --> so this way you still get to have --> as your separator instead of ->.