Question

我在SQL Server 2012上选择查询，其中有多个where条件，这是我的代码：

   SELECT *
    FROM ##TempGet a
    LEFT JOIN Techs b ON a.TECH = b.TechID
    --LEFT JOIN (SELECT * FROM OPENQUERY (Serv,  'SELECT * FROM Hist order by histdate desc')) as c on a.CUST_ACCT = c.CUST_ACCT and c.HISTDATE >= a.sch_date
    LEFT JOIN (SELECT ParamId, ParamType, Value1, Value2, Value3, Status, UpdateBy, UpdateDate FROM Parameter AS Parameter_3 WHERE (ParamType = 'SCABranch')) AS p ON LEFT (SCHAREAS, 1) = p.Value1
WHERE WSTAT = 'P/TC' 
AND (a.CUST_ACCT NOT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM NOT IN (SELECT OFFERNUM from TC))
OR (a.CUST_ACCT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM  IN (SELECT OFFERNUM from TC ) and a.sch_date not in (SELECT SCH_DATE from TC where CUST_ACCT = a.CUST_ACCT and OFFERNUM = a.Offernum))
OR (a.CUST_ACCT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM NOT IN (SELECT OFFERNUM from TC ) and a.sch_date not in (SELECT SCH_DATE from TC where CUST_ACCT = a.CUST_ACCT and OFFERNUM = a.Offernum))

主要发布是法规太复杂的地方，

 WHERE WSTAT = 'P/TC' 
    AND (a.CUST_ACCT NOT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM NOT IN (SELECT OFFERNUM from TC))
    OR (a.CUST_ACCT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM  IN (SELECT OFFERNUM from TC ) and a.sch_date not in (SELECT SCH_DATE from TC where CUST_ACCT = a.CUST_ACCT and OFFERNUM = a.Offernum))
    OR (a.CUST_ACCT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM NOT IN (SELECT OFFERNUM from TC ) and a.sch_date not in (SELECT SCH_DATE from TC where CUST_ACCT = a.CUST_ACCT and OFFERNUM = a.Offernum))

是和它结合还是真的？因为我选择的某些数据不会显示，但它应该在那里显示。

Answer 1

无论

你的括号是对的吗？在这三行中，您打算对这三行进行“或”操作吗？例如。如果WSTAT ='P / TC'应该只应用接下来的三行中的一行？如果是这样，请在括号中包含3

    WHERE WSTAT = 'P/TC' 
        AND  (  -- added bracket
           (a.CUST_ACCT NOT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM NOT IN (SELECT OFFERNUM from TC))
        OR (a.CUST_ACCT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM  IN (SELECT OFFERNUM from TC ) and a.sch_date not in (SELECT SCH_DATE from TC where CUST_ACCT = a.CUST_ACCT and OFFERNUM = a.Offernum))
        OR (a.CUST_ACCT IN (SELECT CUST_ACCT FROM TC) AND a.OFFERNUM NOT IN (SELECT OFFERNUM from TC ) and a.sch_date not in (SELECT SCH_DATE from TC where CUST_ACCT = a.CUST_ACCT and OFFERNUM = a.Offernum))  
             ) -- added bracket

这一切都归结为谓词。简单来说谓词是一个事实陈述，通常在查询的where部分（可以在其他地方完成 - 在INNER / OUTER的ON部分加入HAVING子句。）每个必须为true，并且只有每个谓词为真时才会你得到一个结果。所以你要问

        Get me <the columns I've listed>
    from <the tables I've listed>
    where 
      predicate 1 -- something you've written
      predicate 2 -- WHERE WSTAT = 'P/TC' 
      predicate 3 -- the AND line
      predicate 4 -- the OR line
      predicate 4 -- the other OR

我怀疑你想要

        Get me <the columns I've listed>
    from <the tables I've listed>
    where 
      predicate 1 -- something you've written
      predicate 2 -- WHERE WSTAT = 'P/TC' 
      predicate 3 -- the AND line or the first OR or the 2nd OR

或

对于这样的查询逻辑问题，有时它有助于注释掉查询的一部分，几乎总是一个where子句，以识别哪一个阻止了您的预期数据被返回。然后深入讨论相关部分。

通过多个条件简化选择查询

1 个答案: