我的 WHERE 子句（使用 SQL 2008）有一些问题。我必须创建一个基于 7 个参数返回结果列表的存储过程，其中一些参数可能为空。有问题的是@elements、@categories 和@edu_id。它们可以是 id 列表，也可以为 null。您可以在我的 where 子句中看到，如果参数不为空，我的特定代码可以工作。如果它们为空，我不确定如何对 sql 进行编码。这些字段在数据库中是 INT。
我希望我的问题足够清楚。下面是我的查询。
BEGIN
DECLARE @elements nvarchar(30)
DECLARE @jobtype_id INT
DECLARE @edu_id nvarchar(30)
DECLARE @categories nvarchar(30)
DECLARE @full_part bit
DECLARE @in_demand bit
DECLARE @lang char(2)
SET @jobtype_id = null
SET @lang = 'en'
SET @full_part = null -- full = 1, part = 0
SET @elements = '1,2,3'
SET @categories = '1,2,3'
SET @edu_id = '3,4,5'
select
jobs.name_en,
parttime.fulltime_only,
jc.cat_id category,
je.element_id elem,
jt.name_en jobtype,
jobs.edu_id minEdu,
education.name_en edu
from jobs
left join job_categories jc
on (jobs.job_id = jc.job_id)
left join job_elements je
on (jobs.job_id = je.job_id)
left join job_type jt
on (jobs.jobtype_id = jt.jobtype_id)
left join education
on (jobs.edu_id = education.edu_id)
left join
(select job_id, case when (jobs.parttime_en IS NULL OR jobs.parttime_en = '') then 1 else 0 end fulltime_only from jobs) as parttime
on jobs.job_id = parttime.job_id
where [disabled] = 0
and jobs.jobtype_id = isnull(@jobtype_id,jobs.jobtype_id)
and fulltime_only = isnull(@full_part,fulltime_only)
-- each of the following clauses should be validated to see if the parameter is null
-- if it is, the clause should not be used, or the SELECT * FROM ListToInt... should be replaced by
-- the field evaluated: ie if @elements is null, je.element_id in (je.element_id)
and je.element_id IN (SELECT * FROM ListToInt(@elements,','))
and jc.cat_id IN (SELECT * FROM ListToInt(@categories,','))
and education.edu_id IN (SELECT * FROM ListToInt(@edu_id,','))
order by case when @lang='fr' then jobs.name_fr else jobs.name_en end;
END