拼接SQL字符串实现多条件查询，以前拼接的写法

set @sql=' select * from table where 1=1 '

if (@addDate is not null)

     set @sql = @sql+' and  addDate = '+ @addDate + '  '
if (@name <>'' and is not null)
    set @sql = @sql+ ' and name = ' + @name + ' '
exec(@sql)

下面是 不采用拼接SQL字符串实现多条件查询的解决方案

第一种写法是 感觉代码有些冗余
if (@addDate is not null) and (@name <> '')
      select * from table where addDate = @addDate and name = @name
else if (@addDate is not null) and (@name ='')
      select * from table where addDate = @addDate
else if(@addDate is  null) and (@name <> '')
      select * from table where and name = @name
else if(@addDate is  null) and (@name = '')
select * from table

第二种写法是

select * from table where (addDate = @addDate or @addDate is null) and (name = @name or @name = '')
第三种写法是

SELECT * FROM table where
addDate = CASE @addDate IS NULL THEN addDate ELSE @addDate END,
name = CASE @name WHEN '' THEN name ELSE @name END