请帮我一个MySQL查询,使用PHP访问DATABSE和处理数据:MySQL查询Ø检索基于以下条件的记录
我有变量
1) $content_number_of_characters
2) $number_of_comments
和mysql表名:udjacomments
表udjacomments的
领域:id, full_name, content, comment_url, is_published, and time_added
我想检索每个进入的数组。对于内容,我只想得到内容达到字符$content_number_of_characters
(换句话说,如果$ content_number_of_characters是120,内容是300个字符,我只想要前120个字符)。
(我不知道我怎么能使用mysql LEFT(STR,LEN)进入查询)
然后,我只是想从ID的递减顺序记录($number_of_comments
)编号,并在现场is_published == 1
实施例:
我有记录ID为:50,51,52,53,54,55,56个 所有记录is_published == 1,与ID为55的记录除外;记录ID 55 is_published == 0,最后,可变$number_of_comments
== 3
查询将检索记录56,54,和53
谢谢
THANK YOU可以在查询是:$查询=“选择ID,FULL_NAME,如果(CHAR_LENGTH(内容)> $ content_number_of_characters,SUBSTR(内容,1,$ content_number_of_characters),内容),comment_url,is_published和time_added FROM udjacomments where is_published = 1 order by id desc limit $ number_of_comments“换句话说,我可以将两个查询合并为一个...我正在测试 – IberoMedia
THANX我使用了您的建议,并合并了查询。这是我的最后一个查询:\t $ query =“SELECT id,full_name,if(CHAR_LENGTH(content)>”。$ content_number_of_characters。“,SUBSTR(content,1,”。content_number_of_characters。“),content),comment_url,time_added FROM udjacomments where is_published = 1 order by ID DESC limit“。$ number_of_comments; – IberoMedia