Question

我正在尝试在Microsoft Access SQL中编写此查询，但就我而言，我无法弄清楚代码中的语法错误。

SELECT base.study_group, base.NPI,inv.log_date AS invite_date, rec.log_date as
recieved_date, rej.log_date as reject_date
FROM CODAAC_master AS base
LEFT JOIN Pre_Log AS inv ON base.NPI = inv.NPI AND inv.tracking_event='INVA'
LEFT JOIN Pre_Log AS rec ON base.NPI = rec.NPI AND rec.tracking_event='RECA'
LEFT JOIN Pre_Log AS rej ON base.NPI = rej.NPI AND rej.tracking_event='REJA'
WHERE base.study_year = '2013'
ORDER BY base.study_group, base.NPI;

我得到的错误是：

"Syntax error (missing operator) in query expression"

Answer 1

MS Access需要围绕多个联接的括号：

SELECT base.study_group, 
  base.NPI,
  inv.log_date AS invite_date, 
  rec.log_date as recieved_date, 
  rej.log_date as reject_date
FROM ((CODAAC_master AS base
LEFT JOIN Pre_Log AS inv 
  ON base.NPI = inv.NPI AND inv.tracking_event='INVA')
LEFT JOIN Pre_Log AS rec 
  ON base.NPI = rec.NPI AND rec.tracking_event='RECA')
LEFT JOIN Pre_Log AS rej 
  ON base.NPI = rej.NPI AND rej.tracking_event='REJA'
WHERE base.study_year = '2013'
ORDER BY base.study_group, base.NPI;

Answer 2

您需要在连接之间添加括号，因为它在MS Access上是必不可少的。（这在其他RDBMS上是可选的）

SELECT  base.study_group, 
        base.NPI,
        inv.log_date AS invite_date, 
        rec.log_date as recieved_date, 
        rej.log_date as reject_date
FROM  ((CODAAC_master AS base LEFT JOIN Pre_Log AS inv 
            ON base.NPI = inv.NPI AND inv.tracking_event='INVA')
        LEFT JOIN Pre_Log AS rec 
            ON base.NPI = rec.NPI AND rec.tracking_event='RECA')
        LEFT JOIN Pre_Log AS rej 
            ON base.NPI = rej.NPI AND rej.tracking_event='REJA'
WHERE base.study_year = '2013'
ORDER BY base.study_group, base.NPI;

Extra Source: Multiple LEFT JOINs in MS Access

无法弄清楚Access SQL语法错误

2 个答案: