MySQL条件查询

Question

我正在尝试编写查询以从表中选择一行（附带的屏幕截图）。这是特殊的，*表示任何价值。我需要选择Amount应该在开始金额和结束金额之间的行，而部门应该是IT。

Country和Sub Department的条件有点棘手。如果所选国家/地区不在Country列中，则查询应该返回*的记录，子部门也是如此。

我尝试了一种基于Department和数量选择列的方法

Select * from table_name where Department = 'IT' 
and 1000 BETWEEN Start Amount AND End Amount

但是，在此之后我不知道如何以低于条件获得结果。

如果国家不是印度，那么我应该得到所有*个结果。

Answer 1

我相信你想要的东西：

  SELECT * 
    FROM table_name 
   WHERE Department = 'IT' 
     AND 1000 BETWEEN `Start Amount` AND `End Amount`
     AND country IN ('India','*')
     AND `Sub Department` IN ('SD2','*')
ORDER BY country = 'India' DESC,
         `Sub Department` = 'SD2' DESC
   LIMIT 1

Answer 2

使用union all按优先顺序将组号分配给country / sub_department的每个允许组合，即(India,SD1) (India,*) (*,*)，然后只选择组号最小的行。

select t1.* from (
    Select t1.* ,
    if(@minGroup > groupNumber, @minGroup := groupNumber, @minGroup) minGroupNumber
    from (
        Select t1.*, 1 groupNumber from table_name t1
        where Department = 'IT' 
        and 1000 BETWEEN `Start Amount` AND `End Amount`
        and country = 'India'
        and sub_department = 'SD1'

        union all

        Select t1.*, 2 groupNumber from table_name t1
        where Department = 'IT' 
        and 1000 BETWEEN `Start Amount` AND `End Amount`
        and country = 'India'
        and sub_department = '*'

        union all

        Select t1.*, 3 groupNumber from table_name t1
        where Department = 'IT' 
        and 1000 BETWEEN `Start Amount` AND `End Amount`
        and country = '*'
        and sub_department = '*'
    ) t1 cross join (select @minGroup := 3) t2
) t1 where groupNumber = @minGroup

Answer 3

重新发送bcz，明星被截断

选择NVL（tc.Country，'*'）Country_Column_name，         NVL（tsd.Sub_Dept，'*'）Sub_Dept_Column_name 来自table_name tn LEFT OUTER JOIN table_country tc ON tn.Country = tc.Country LEFT OUTER JOIN table_sub_dept tsd ON tn.Sub Dept = tsd.Sub Dept 哪个部门='IT' 和1000开始金额和结束金额

注意：国家和地区Sub Dpt表应该具有唯一列，并且应该在连接中使用。