MYSQL-列值出现的未分组计数器
Mysql表按键asc排序: 表中不存在列出现\u计数器。 我想进行查询,它可以告诉我每行的发生\u计数器的值:MYSQL-列值出现的未分组计数器,mysql,Mysql,Mysql表按键asc排序: 表中不存在列出现\u计数器。 我想进行查询,它可以告诉我每行的发生\u计数器的值: // pseudo-code: foreach(row) { if(isFirstOccurenceOfKey(current_key)) { current_OCCURENCE_COUNTER = 1; } else { current_OCCURENCE_COUNTER = previous_OCCURENCE_COUNTER +
// pseudo-code:
foreach(row) {
if(isFirstOccurenceOfKey(current_key)) {
current_OCCURENCE_COUNTER = 1;
} else {
current_OCCURENCE_COUNTER = previous_OCCURENCE_COUNTER + 1;
}
}
我不希望按键分组出现内容。我只想取消分组
在这种情况下,一个查询或一些子查询可以完成吗?我希望,我正确理解了您的问题。事件内容是您在问题中定义的表
select c.*,
( select count(*)
from occurence_conter c1
where c1.key = c.key
and c1.id <= c.id ) as OccurenceCounter
from occurence_conter c;
我希望,我正确地理解了你的问题。事件内容是您在问题中定义的表
select c.*,
( select count(*)
from occurence_conter c1
where c1.key = c.key
and c1.id <= c.id ) as OccurenceCounter
from occurence_conter c;
可能的重复可能的重复可能的重复