Question

这是示例表：

Column             | 1st record | 2nd record | 3rd record | 4th record | etc<br />
id (primary)       | 1          | 5          | 8          | 12         | etc<br />
name               | name 1     | name 2     | name 3     | name 4     | etc<br />
date               | date 1     | date 2     | date 3     | date 4     | etc<br />
callValue (unique) | val1       | val2       | val3       | val4       | etc

我选择一行作为要显示的数据（例如：具有callValue的行：val3）。但我无法找到解决方案：
我需要选择上一行和下一行。所以，在这个例子中，我需要从行vallValue：val4和callValue：val2，或id：5和id：12获取数据。

id = id + - 1无法完成，因为id因删除行而不必连续。

Answer 1

试试这个：

select * from test where callValue = 'val3'  
union all  
(select * from test where callValue < 'val3' order by id desc limit 1) 
union all  
(select * from test where callValue > 'val3' order by id asc limit 1)

或

select * from test where id = 8
union all  
(select * from test where id < 8 order by id desc limit 1) 
union all  
(select * from test where id > 8 order by id asc limit 1)

Answer 2

获得身份8后，您应该可以对以下内容进行修改：

select * from mytable
where id < 8
order by id desc
limit 1

和

select * from mytable
where id > 8
order by id asc
limit 1

表示上一张和下一张唱片。

Answer 3

这有效：

select a.id, a.name, a.date, a.callValue 
FROM
(
    select @r0 := @r0 + 1 as rownum, id, name, date, callValue from TABLE
    , (SELECT @r0 := 0) r0
) a,
(
    select @r1 := @r1 + 1 rownum, id, name, date, callValue from TABLE
    , (SELECT @r1 := 0) r1 
) b
where b.callValue = val3 and b.rownum between (a.rownum-1 and a.rownum+1)

它将表扩展为2维，因此您可以将第一个表中的行与第二个表中的任何行进行比较。

Answer 4

select *
from callvalue
where id <  maxd
(
select max(id) as maxd
from callvalue
where id = maxd
)

MySQL在行之后选择

4 个答案: