what does '#@' means in oracle query

Question

I have oracle query below

SELECT   
tr.hetid,   
tr.hfncd,   
tr.op_code,   
tr.bps_batch_seq,   
substr(op_code, -3) add_del_flag,   
tr.ack_msg,   
'#@' seg_data   
from table_name   
where <condition>   

I don't understand, what '#@' means in the query

Answer 1

'#@'是一个简单的text literal
就像其他文字文字一样。

SELECT 
    'some name' As name,
    'Some text' as Text,
    'This is some string' As String,
    '#@' As seg_data   
FROM dual

NAME      TEXT      STRING              SE
--------- --------- ------------------- --
some name Some text This is some string #@