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)
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