在Oracle SQL查询中比较日期时出错

Question

我正在写一个SQL查询，我需要将varchar列值转换为日期并在where子句中使用它。

以下是我正在尝试的查询；

SELECT *
FROM
  ( SELECT DISTINCT t1.record_id,
    t1.column_name,
    t1.value,
    t1.row_index,
    t1.start_date,
    t1.end_date,
    t2.value AS val
   FROM sf_monthly_fin_exp t1,
    sf_monthly_fin_exp t2
  WHERE t1.row_index         = t2.row_index
  AND t1.generated_report_id = t2.generated_report_id
  AND t1.generated_report_id =11700
  AND t2.column_name         = 'Date'
  AND t2.value              <> 'Total'
  AND t1.column_name = 'xyz'
  ORDER BY t1.row_index
  )
WHERE TO_DATE(val, 'dd/mm/YYYY') = TO_DATE('05/01/2014', 'dd/mm/YYYY');

我在比较时将值转换为日期类型，但出现以下错误；

ORA-01858: a non-numeric character was found where a numeric was expected
01858. 00000 - a non-numeric character was found where a numeric was       expected.

我在查询中做错了什么，任何帮助将不胜感激。

Answer 1

您尝试将“ t2.value”转换为日期。 可能您想转换“ t1.value”：

WHERE TO_DATE(value, 'dd/mm/YYYY') = TO_DATE('05/01/2014', 'dd/mm/YYYY');