Problème BLOB mysql

Question

Cela fonctionne très bien.

SET @postrownum = 0, @postrank = 1, @postprev_val = NULL, @postprev_postnum = NULL; 

SELECT @postrownum := @postrownum + 1 AS row, 
@postrank := IF(@postprev_val!=postcount,@postrownum,@postrank) AS postrank, 
c.user_id, 
@postprev_postnum := IF(@postprev_val!=postcount,@postprev_val-postcount,@postprev_postnum) as morepost, 
@postprev_val := postcount as postcount, 
postcount*5 as postpoint from 

(
select user_id,count(user_id) as postcount from post group by user_id order by postcount desc) as c 

Ce ne marche pas beau travail

SET @postrownum = 0, @postrank = 1, @postprev_val = NULL, @postprev_postnum = NULL; 

select id,postrank,morepost,postcount,postpoint from user as a left join 

(SELECT @postrownum := @postrownum + 1 AS row, 
@postrank := IF(@postprev_val!=postcount,@postrownum,@postrank) AS postrank, 
c.user_id, 
@postprev_postnum := IF(@postprev_val!=postcount,@postprev_val-postcount,@postprev_postnum) as morepost, 
@postprev_val := postcount as postcount, 
postcount*5 as postpoint from 

(
select user_id,count(user_id) as postcount from post group by user_id order by postcount desc) as c) as b on a.id=b.user_id 

morepost retournera avec [blob-1B], bizarre. Puis-je avoir une aide s'il vous plait!

Answer 1

bizarre, le problème est avec ceci.

@postprev_postnum = NULL;

i réglé sur

@postprev_postnum = 0;

et cela fonctionne pour le 2ème code.

Ne comprend pas pourquoi tu.