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I am posting for the first time.
I am using Delphi10.3.3 and DOA4.1.3.5 to connect to Oracle19c.
Oracle's character code uses JA16SJIS.
I get an ORA-1480 error, "trailing null missing from STR bind value" when trying to INSERT a string of about 2000 bytes.
BytesPerCharacter of TOracleSession is set to bcAutoDetect.
Is there any way to solve this?
I searched the source code and found the following description in the relevant part.
"Q.SQL.Text := 'select length(chr(2000000000)) l4, length(chr(2000000)) l3, length(chr(20000)) l2, ''c'' c1 from dual';"
Could you tell me the meaning of this SELECT statement?
Thank you very much.

P.S.
The character string is a character string exceeding 2000 bytes in SJIS code including Japanese.
Also when I set BytesPerChanacter to bc1Byte I get no error.
Is it okay to set BytesPerChanacter to bc1Byte during normal use?

I'm not sure what could cause this. If forcing the character size to 1 byte per character fixes it, then this may be a solution.

Thank you for your reply.
I understand that setting 1 byte is not a problem.
By the way, I also wrote in the question,
”select length(chr(2000000000)) l4, length(chr(2000000)) l3, length(chr(20000)) l2, 'c' c1 from dual”
Can you tell me what this SELECT tells me?
Thank you.