当我在 Python 中运行 SQL MERGE 语句时，如何知道哪些记录会导致问题

Question

我在 python 中运行下面的代码。它正在从一个表合并到另一个表。但有时由于重复，它给了我错误。我如何知道哪些记录已合并，哪些未合并，以便我可以跟踪记录并修复它。或者至少，如何让我的代码日志提示错误消息以便我可以跟踪它？

# Exact match client on NAME/DOB (not yet using name_dob_v)
    sql = """
    merge into nf.es es using (
        select id, name_last, name_first, dob 
        from fd.emp
        where name_last is not null and name_first is not null and dob is not null
    ) es6
    on (upper(es.patient_last_name) = upper(es6.name_last) and upper(es.patient_first_name) = upper(es6.name_first)
        and es.patient_dob = ems6.dob)
    when matched then update set 
        es.client_id = ems6.id
      , es.client_id_comment = '2 exact name/exact dob match'
    where
           es.client_id is null -- exclude those already matched
       and es.patient_last_name is not null and es.patient_first_name is not null and es.patient_dob is not null 
       
       and es.is_lock = 'Locked' and es.is_active = 'Yes' and es.patient_last_name NOT IN ('DOE','UNKNOWN','DELETE', 'CANCEL','CANCELLED','CXL','REFUSED')
    """
        log.info(sql)
        curs.execute(sql)
        msg = "nf.es rows updated with es6 client_id due to exact name/dob match: %d" % curs.rowcount
        log.info(msg)
        emailer.append(msg)

Answer 1

你不知道，merge 不会告诉你的。您必须真正找到他们并采取适当的行动。

也许选择不同的值会有所帮助：

 merge into nf.es es using (
        select DISTINCT                       --> this
          id, name_last, name_first, dob 
        from fd.emp
        ...

---

如果它仍然不起作用，则将表与using 子句中的表合并到您已经在执行的所有列上，并查看哪些行是重复的。像这样的：

  SELECT *
    FROM (SELECT d.id,
                 d.name_last,
                 d.name_first,
                 d.dob
            FROM fd.emp d
                 JOIN nf.es e
                    ON     UPPER (e.patient_last_name) = UPPER (d.name_last)
                       AND UPPER (e.patient_first_name) = UPPER (d.name_first)
           WHERE     d.name_last IS NOT NULL
                 AND d.name_first IS NOT NULL
                 AND d.dob IS NOT NULL)
GROUP BY id,
         name_last,
         name_first,
         dob
  HAVING COUNT (*) > 2;