Query gives me ORA-01722 invalid number

Question

I'm on Release 12 and when I run this query I get ORA-01722 invalid number:
select api.invoice_num,
to_char(api.invoice_date,'MM/DD/YYYY'),
to_char(api.terms_date,'MM/DD/YYYY'), to_char(glh.posted_date,'MM/DD/YYYY'),
NVL(glj.entered_dr,0)-NVL(glj.entered_cr,0) expense,
cc.segment1 BFY, cc.segment2 FUND,cc.segment3 ORG, cc.segment4 PROG, cc.segment5 BOC,
cc.segment6 GL_ACCT, cc.segment7 ACT, cc.segment8 PROJ,glj.period_name
from gl.gl_je_headers glh, gl.gl_je_lines glj, ap.ap_invoices_all api, gl.gl_code_combinations cc
where glj.code_combination_id = cc.code_combination_id
and glh.je_header_id = glj.je_header_id
and api.invoice_id(+) = glj.reference_2
and cc.segment6 = '9235423';
But when I comment out the api.invoice_num it runs fine:
select --api.invoice_num,
to_char(api.invoice_date,'MM/DD/YYYY'),
to_char(api.terms_date,'MM/DD/YYYY'), to_char(glh.posted_date,'MM/DD/YYYY'),
NVL(glj.entered_dr,0)-NVL(glj.entered_cr,0) expense,
cc.segment1 BFY, cc.segment2 FUND,cc.segment3 ORG, cc.segment4 PROG, cc.segment5 BOC,
cc.segment6 GL_ACCT, cc.segment7 ACT, cc.segment8 PROJ,glj.period_name
from gl.gl_je_headers glh, gl.gl_je_lines glj, ap.ap_invoices_all api, gl.gl_code_combinations cc
where glj.code_combination_id = cc.code_combination_id
and glh.je_header_id = glj.je_header_id
and api.invoice_id(+) = glj.reference_2
and cc.segment6 = '610001';
I don't get it because ap.invoice_num is a character field, so why would it be checking to see if it's a number? What could be the problem?

Answer 1

Welcome to the forums !
Pl post details of database version, along with an explain plan for this statement (with and without the first field being selected)
Master Note: Recommended Method for Obtaining a Formatted Explain Plan (Doc ID 235530.1)
https://supporthtml.oracle.com/ep/faces/secure/km/DocumentDisplay.jspx?id=235530.1&h=Y
HTH
Srini