Question

我有这个select语句，它根据某些条件在我的表中找到重复项。

选择是：

select  DIVISION, FIPS_COUNTY_CODE, LAST, SUFFIX, FIRST, TITLE, BIRTHDATE, count(*)
  from work
  group by  DIVISION, FIPS_COUNTY_CODE, LAST, SUFFIX, FIRST, TITLE, BIRTHDATE
  having count(*) > 1

我想将此转换为将字母附加到表格中的字段的更新。例如，

UPDATE [WORK] SET BAD_CODES = BAD_CODES  & 'D'

有关如何制作此更新声明的任何想法？

Answer 1

我相信这应该做到，但我对Access不是很熟悉：

UPDATE [WORK] 
SET BAD_CODES = BAD_CODES  & 'D'
WHERE EXISTS (SELECT DIVISION, FIPS_COUNTY_CODE, LAST, SUFFIX, FIRST, TITLE, BIRTHDATE, COUNT(*)
              FROM work b
              WHERE [WORK].DIVISION = b.DIVISION
                AND [WORK].FIPS_COUNTY_CODE = b.FIPS_COUNTY_CODE
                AND [WORK].LAST = b.LAST
                AND [WORK].SUFFIX = b.SUFFIX
                AND [WORK].FIRST = b.FIRST
                AND [WORK].TITLE = b.TITLE
                AND [WORK].BIRTHDATE = b.BIRTHDATE
              GROUP BY DIVISION, FIPS_COUNTY_CODE, LAST, SUFFIX, FIRST, TITLE, BIRTHDATE
              HAVING COUNT(*) > 1
             )

这应该是等效的，但是如果您想在更新中使用子查询中的值，则非常有用：

UPDATE T 
SET    BAD_CODES = BAD_CODES  & 'D'
FROM   work AS T 
JOIN (SELECT DIVISION, FIPS_COUNTY_CODE, LAST, SUFFIX, FIRST, TITLE, BIRTHDATE, COUNT(*)
      FROM work                      
      GROUP BY DIVISION, FIPS_COUNTY_CODE, LAST, SUFFIX, FIRST, TITLE, BIRTHDATE
      HAVING COUNT(*) > 1
      ) AS S
  ON  T.DIVISION = S.DIVISION
  AND T.FIPS_COUNTY_CODE = S.FIPS_COUNTY_CODE
  AND T.LAST = S.LAST
  AND T.SUFFIX = S.SUFFIX
  AND T.FIRST = S.FIRST
  AND T.TITLE = S.TITLE
  AND T.BIRTHDATE = S.BIRTHDATE

如何将此select duplicates语句转换为更新？

1 个答案: