Sql 我的查询筛选没有按我希望的方式工作

我有3种过滤方法：

名字

按列表

向大家展示

我正在使用ASP.NET3.5和SQLServer2008。使用ADO.NET和存储过程

我将列表作为表值参数传递（但我使用表变量进行测试），并将名称作为nvarchar传递。我将“show all”设置为ISNULL（@var，column）=column。显然，我质疑这一点的方式不是利用短路，也不是我对子句如何工作的理解不足。所发生的事情是，如果我将@var='somestring'设置为空，并在表变量中插入null，那么它将正确过滤。如果我设置@var=null并在表变量中插入'some string'，那么我会得到每一条记录，在这里我应该得到'some string'

守则：

declare @resp1 nvarchar(32)
set @resp1 = null
declare @usersTable table
(responsible nvarchar(32))
--insert into @usersTable (responsible) values (null)
insert into @usersTable (responsible) values ('ssimpson')
insert into @usersTable (responsible) values ('kwilcox')
select uT.responsible, jsq.jobnumber, jsq.qid, aq.question, aq.section, aq.seq, answers.* 
from answers
inner join jobno_specific_questions as jsq on answers.jqid = jsq.jqid
inner join apqp_questions as aq on jsq.qid = aq.qid
left join @usersTable as uT on uT.responsible = answers.responsible
where answers.taskAction = 1 and (uT.responsible is not null or ISNULL(@resp1, Answers.responsible) = Answers.responsible)
order by aq.section, jsq.jobnumber, answers.priority, aq.seq

declare @filterPick bit 
declare @usersTable table
(responsible nvarchar(32))
insert into @usersTable (responsible) values (null)
--insert into @usersTable (responsible) values ('ssimpson')
--insert into @usersTable (responsible) values ('kwilcox')
if exists (select * from @usersTable where responsible is not null)
   begin
      set @filterPick = 1
   end
else
   begin
      set @filterPick = 0
   end
select *
from answers
inner join jobno_specific_questions as jsq on answers.jqid = jsq.jqid
inner join apqp_questions as aq on jsq.qid = aq.qid
left join @usersTable as uT on answers.responsible = uT.responsible
where answers.taskAction = 1 and (uT.responsible is not null or (isnull(uT.responsible, answers.responsible) = answers.responsible and @filterPick = 0))
order by aq.section, jsq.jobnumber, answers.priority, aq.seq

这就是我想到的。虽然很难看

declare @resp1 nvarchar(32)
set @resp1 = 'rrox'
declare @filterPick int
declare @usersTable table
(responsible nvarchar(32))
insert into @usersTable (responsible) values (null)
--insert into @usersTable (responsible) values ('ssimpson')
--insert into @usersTable (responsible) values ('kwilcox')
if @resp1 is null 
begin
   set @filterPick = 2
end
else
begin
   set @filterPick = 1
end
select uT.responsible, jsq.jobnumber, jsq.qid, aq.question, aq.section, aq.seq, answers.* 
from answers
inner join jobno_specific_questions as jsq on answers.jqid = jsq.jqid
inner join apqp_questions as aq on jsq.qid = aq.qid
left join @usersTable as uT on uT.responsible = answers.responsible
where answers.taskAction = 1 and 
(case
    when uT.responsible is not null then 2
    when ISNULL(@resp1, Answers.responsible) = Answers.responsible then 1          
 end = @filterPick )
order by aq.section, jsq.jobnumber, answers.priority, aq.seq

嗯。我想我明白了。我删除了@resp1，因为它不是必需的，我只是使用表值参数@usersTable（但这里我使用一个表变量进行测试）。我添加了一个标志@filterPick，这样我就可以只显示@usersTable或answers.taskAction=1的每个记录中的值

守则：

declare @resp1 nvarchar(32)
set @resp1 = null
declare @usersTable table
(responsible nvarchar(32))
--insert into @usersTable (responsible) values (null)
insert into @usersTable (responsible) values ('ssimpson')
insert into @usersTable (responsible) values ('kwilcox')
select uT.responsible, jsq.jobnumber, jsq.qid, aq.question, aq.section, aq.seq, answers.* 
from answers
inner join jobno_specific_questions as jsq on answers.jqid = jsq.jqid
inner join apqp_questions as aq on jsq.qid = aq.qid
left join @usersTable as uT on uT.responsible = answers.responsible
where answers.taskAction = 1 and (uT.responsible is not null or ISNULL(@resp1, Answers.responsible) = Answers.responsible)
order by aq.section, jsq.jobnumber, answers.priority, aq.seq

declare @filterPick bit 
declare @usersTable table
(responsible nvarchar(32))
insert into @usersTable (responsible) values (null)
--insert into @usersTable (responsible) values ('ssimpson')
--insert into @usersTable (responsible) values ('kwilcox')
if exists (select * from @usersTable where responsible is not null)
   begin
      set @filterPick = 1
   end
else
   begin
      set @filterPick = 0
   end
select *
from answers
inner join jobno_specific_questions as jsq on answers.jqid = jsq.jqid
inner join apqp_questions as aq on jsq.qid = aq.qid
left join @usersTable as uT on answers.responsible = uT.responsible
where answers.taskAction = 1 and (uT.responsible is not null or (isnull(uT.responsible, answers.responsible) = answers.responsible and @filterPick = 0))
order by aq.section, jsq.jobnumber, answers.priority, aq.seq

---

您是否考虑过将WHERE子句更改为类似以下内容：

WHERE Answers.taskAction = 1 
AND(ISNULL(@resp1, Answers.responsible) = Answers.responsible 
    OR Answers.responsible IN (SELECT responsible FROM uT))

---

不是加入表值参数？

我对你的问题有点困惑，但我将试一试

首先，我怀疑返回错误记录的问题与比较空值有关。要演示我所说的内容，请查询您想要的任何表并将其添加到末尾：

WHERE null = null

不会返回任何记录。在您的代码中，我将更改：

where answers.taskAction = 1 and (uT.responsible is not null or ISNULL(@resp1, Answers.responsible) = Answers.responsible)

到

---

然后查看是否返回所需的结果。

您能提供一些您正在处理的示例数据吗？我很难理解你想问什么。另外，我不相信SQLServer使用任何短路：您到底想过滤什么？您似乎有一个变量（脚本中有@resp1）和一个表。因此，如果@resp1变量不为null，您希望对其进行筛选；如果@resp1为null，您希望对表中的所有内容进行筛选？我正在尝试对@resp1或@userTable进行筛选。所以要么按一个名字过滤，要么按一组名字过滤。@安德鲁：是的，这就是我想做的。它似乎不起作用。不幸的是它不起作用。但我不知道我在哪里比较空值。ISNULL返回第一个非null值是否正确？