We have a table with a column name A with type nvarchar(23).

following query will always return 23 which means that the actual length of all records are 23.

select length(trim(req.A)), count(*)
  from tableName req
group by length(trim(req.A));
|23                 |1006    |

But when we select from this table with following query it behaves different and it seems that the last character is always removed in result Gridview in the pl/sql developer.

select LENGTHB(req.A) lenb, length(req.A) len, req.* from tableName req
where req.A = 'NHBBBBB1398052635902235'; -- Note to the equal sign and the last charactar (5) of the where clause

the result is:

|lenb|len|          A           |
|46  |23 |NHBBBBB139805263590223|

As you can see the last character (5) is removed in the select result.

Also when we rewrite previous query with to_char() or run it in sqlplus it works fine & return correct result with the length of 23 and (5) as the last character.

select LENGTHB(req.A) lenb, length(req.A) len, to_char(req.A) from tableName req
where req.A = 'NHBBBBB1398052635902235';

the result is:

|lenb|len|    to_char(req.A)     |
|46  |23 |NHBBBBB1398052635902235|

Can you please explain whats happen!? Is this related to pl/sql configs? How to solve this?

  • What happens when you run the queries in sqlplus? Aug 18, 2019 at 12:03
  • @Colin'tHart unfortunately, the db is on our customer environment and we don't have direct access to it. They denied to run this query in sqlplus.
    – Ziaa
    Aug 18, 2019 at 13:58
  • What is the datatype of the column in question? What is the database character set?
    – mustaccio
    Aug 18, 2019 at 14:07
  • What if you try this? ``` select LENGTHB(req.A) lenb, length(req.A) len, req.* from tableName req where req.A = N'NHBBBBB1398052635902235'; ``` A literal in between quotes is created as VARCHAR2. If you put the "N" before the quote, it will be created as NVARCHAR2.
    – Max
    Aug 24, 2019 at 17:09

1 Answer 1


It seems that the problem was an old version of PL/SQL Developer which our customers used. When they updated to the newer version, the problem has been solved.

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