Question

我有两张表如下

CREATE TABLE messageTable (ID INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE, USERID INTEGER, FROMUSER TEXT, TOUSER TEXT, MESSAGEBODY TEXT, STATUS INTEGER, CREATEDTIME TEXT);

和

CREATE TABLE chatPersonTable (ID INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE, USERID INTEGER, NAME TEXT, IMAGEURL TEXT, LASTACTIVE TEXT, LOGEDINUSERID INTEGER, STATUS INTEGER);

我想从chatPersonTable.USERID = messageTable.USERID的messagetable中获取来自chatPersonTable for LOGEDINUSERID =“119”的所有列以及lastMessage（仅最后一条消息）我正在使用以下查询，但它不能正常工作

 SELECT 
m.ID as CHATID, p.USERID, p.NAME, p.IMAGEURL, p.LASTACTIVE, p.logedinuserid, p.status, m.MESSAGEBODY, m.CREATEDTIME 
from chatPersonTable as p join messageTable as m

 on p.USERID = m.USERID 
 where p.LOGEDINUSERID = "119" 
 group by m.USERID order by m.CREATEDTIME desc

Answer 1

您好，您可以使用以下查询来获取数据。这将使用自联接

获取数据

SELECT  m.ID as CHATID, p.USERID, p.NAME, p.IMAGEURL, p.LASTACTIVE, p.logedinuserid, p.status, m.MESSAGEBODY, m.CREATEDTIME ,**MAX(m.id)**
from chatPersonTable as p join messageTable as m on p.USERID = m.USERID where p.LOGEDINUSERID = "119" group by m.USERID

由于

SQLite查询无法在iphone中运行

1 个答案: