如何从表中获取唯一数据？

Question

我有一个在mysql中有bus_id和cus_id的表。我想从表中得到B108作为返回值，因为我想要的结果的值不等于C108而C108也有B109。所以我也不想要第3行的价值。我希望只得到第2行作为我的结果。请建议我这些表的选择查询。

我的表是：

Answer 1

您可以单独使用组表并检测每列的重复值，然后使用这些值过滤表。

    select * from table 
    where cus_id not in
    (select cus_id from table 
    group by cus_id
    having count(*) > 1)
    and
    bus_id not in
    (select bus_id from table 
    group by bus_id
    having count(*) > 1)

Answer 2

试试这个：

select bus_id from table where bus_id not in (select bus_id from table where cus_id='c108')

Answer 3

我还没有测试过，但这样的事情可能有用

SELECT bus_id FROM table WHERE bus_id NOT IN（SELECT bus_id FROM table WHERE cus_id = C108）

Answer 4

您可以根据自己的情况使用mysql DISTINCT 功能。

例如。 从table_name中选择distinct（column_name）WHERE cus_id＆lt;＆gt; 'C108'AND bus_id＆lt;＆gt; 'B109';

Answer 5

尝试此查询

CREATE TABLE BUS
    (`cb_id` int, `bus_id` varchar(4), `cus_id` varchar(4))
;

INSERT INTO BUS
    (`cb_id`, `bus_id`, `cus_id`)
VALUES
    (1, 'B101', 'C108'),
    (2, 'B108', 'C101'),
    (3, 'B109', 'C102'),
    (24, 'B109', 'C108')
;




SELECT
    * 
FROM BUS B
WHERE cus_id<>'C108'
AND NOT EXISTS(SELECT * FROM BUS B1 
        WHERE 
             B1.BUS_ID=B.BUS_ID 
         AND B1.cus_id='C108')

Answer 6

如果您的意思是忽略列bus_id或cus_id中有2个或更多数据的记录，也许您可​​以使用此查询：

select * from buscus a where
   a.bus_id not in (select b.bus_id from (select count(bus_id) as cb, bus_id FROM BusCus group by bus_id) b where    b.cb > 1) 
and
   a.cus_id not in (select c.cus_id from (select count(cus_id) as cc, cus_id FROM BusCus group by cus_id) c where c.cc >    1)