ORA-01858: a non-numeric character was found where a numeric was expected

Question

hi ,
This was the code which shows the sales rep invoice amount and collected amount but while running report thru concurrent program its showing the following error:
ORA-01858: a non-numeric character was found where a numeric was expected
WHERE TO_CHAR ( TO_DATE ( PS.GL_DATE , 'DD/MON/YY' ) , 'MON-YYYY' ) BETWEEN TO_CHAR ( TO_DATE ( : ==> P_todate , 'YYYY/MM/DD' ) , 'MON-YYYY' ) AND TO_CHAR ( TO_DATE ( : P_todate , 'YYYY/MM/DD' ) , 'MON-YYYY' ) AND ps.customer_id = cust.custome
The Actual Code was this
SELECT SUBSTR(SALES.name,1,50) salesrep_name_inv,
--ps.CLASS,
SUM(ABS(ps.acctd_amount_due_remaining)) acctd_amt,
SUM(ABS(ps.amount_due_remaining)) amt_due_remaining_inv,
SUM(ABS(ps.amount_adjusted)) amount_adjusted_inv,
SUM(ABS(ps.amount_applied)) amount_applied_inv,
SUM(ABS(ps.amount_credited)) amount_credited_inv,
          SALES.salesrep_id,
NULL "REMARKS"
-- ps.gl_date gl_date_inv,
FROM ra_cust_trx_types ctt,
ra_customers cust,
ar_payment_schedules ps,
ra_salesreps SALES,
ra_site_uses site,
ra_addresses addr,
ra_cust_trx_line_gl_dist gld,
gl_code_combinations c,
ra_customer_trx ct
WHERE TO_CHAR(TO_DATE(PS.GL_DATE,'DD/MON/YY'),'MON-YYYY')
BETWEEN TO_CHAR(TO_DATE(:P_todate,'YYYY/MM/DD'),'MON-YYYY') AND TO_CHAR(TO_DATE(:P_todate,'YYYY/MM/DD'),'MON-YYYY')
AND ps.customer_id = cust.customer_id
AND ps.customer_trx_id = ct.customer_trx_id
AND ps.cust_trx_type_id = ctt.cust_trx_type_id
AND NVL(ct.primary_salesrep_id, -3) = SALES.salesrep_id
AND ps.customer_site_use_id+0 = site.site_use_id(+)
AND site.address_id = addr.address_id(+)
AND TO_CHAR(TO_DATE(PS.GL_DATE_CLOSED,'DD/MON/YY'),'MON-YYYY')
BETWEEN TO_CHAR(TO_DATE(:P_todate,'YYYY/MM/DD'),'MON-YYYY') AND TO_CHAR(TO_DATE(:P_todate,'YYYY/MM/DD'),'MON-YYYY')
--AND    ps.gl_date_closed > TO_DATE(:P_todate,'MON-YYYY')
AND ct.customer_trx_id = gld.customer_trx_id
AND gld.account_class = 'REC'
AND gld.latest_rec_flag = 'Y'
AND gld.code_combination_id = c.code_combination_id
AND sales.salesrep_id is not null and sales.name is not null
-- and ps.payment_schedule_id+0 < 9999
-- AND SALES.salesrep_id ='1001'
GROUP BY SALES.name,
--ps.CLASS,
SALES.salesrep_id

Answer 1

So to_date function accepts a string as input and returns a date. When a date is input instead, it is implicity converted to the required type of the function paremeter, which is a string, so that to_date can convert it back to a date again.
If you are lucky with the implicit conversion, you get the same date back, if you are not you might get a different date or an error.
From your query it appears that this conversion from a date, to a string, to a date, and then back to a string using to_char this time, is being done to remove the time or day part of the date. The actual range comparison is being done on strings rather than dates, which is dangerous as strings sort differently than dates.
In this example if I sort by date, Jan 01 comes between Dec 00 and Feb 01 as you would expect.
SQL> select * from t order by d;
D
12-01-2000
01-01-2001
02-01-2001When converted to strings, Feb 01 comes between Dec 00 and Jan 01, which is probably not the desired result
SQL> select * from t order by to_char(d,'DD-MON-YY');
D
12-01-2000
02-01-2001
01-01-2001If you want to remove time and day parts of dates you should use the trunc function
trunc(d) removes the time, trunc(d,'mm') will remove the days to start of month.
http://download-east.oracle.com/docs/cd/B19306_01/server.102/b14200/functions201.htm#i79761