Question

I am trying to count the total comments posted by single user. Here is the table structure of the comments table:

CREATE TABLE `PLD_COMMENT` (
   `ID` int(11) NOT NULL auto_increment,        
   `ITEM_ID` varchar(11) NOT NULL,
   `USER_ID` varchar(11) NOT NULL,
   `USER_NAME` varchar(255) NOT NULL, 
   `COMMENT` longtext,
   `COMMENT_TITLE` varchar(255) default NULL,
   `COMMENT_RATING` tinyint(1) default '1', 
   `TYPE` int(11) NOT NULL, 
   `DATE_ADDED` timestamp NOT NULL 
       default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
   `IPADDRESS` varchar(15) default NULL,
   `STATUS` varchar(11) NOT NULL, 
    PRIMARY KEY  (`ID`)  
) ENGINE=MyISAM AUTO_INCREMENT=4 DEFAULT CHARSET=latin1

Here is the table structure for user table

CREATE TABLE `pld_user`(
    `ID` int(11) NOT NULL auto_increment,
    `LOGIN` varchar(100) NOT NULL,
    `NAME` varchar(255) NOT NULL,
    `PASSWORD` varchar(46) NOT NULL,
    `LEVEL` tinyint(4) NOT NULL default '0',
    `RANK` tinyint(4) NOT NULL default '0',
    `ACTIVE` tinyint(4) NOT NULL default '0',
    `LAST_LOGIN` timestamp NOT NULL 
        default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
    `REGISTRATION_DATE` timestamp NOT NULL default '0000-00-00 00:00:00',
    `AUTH_IMG` varchar(255) default NULL,
    `AUTH_IMGTN` varchar(255) default NULL,
    `SUBMIT_NOTIF` tinyint(4) NOT NULL default '1', 
    `PAYMENT_NOTIF` tinyint(4) NOT NULL default '1', 
    `ADDRESS` varchar(255) default NULL, 
    `EMAIL` varchar(255) NOT NULL,
    `WEBSITE` varchar(255) default NULL, 
    `WEBSITE_NAME` varchar(255) default NULL,
    `INFO` varchar(255) default NULL, 
    `ANONYMOUS` tinyint(4) NOT NULL default '0', 
    `LANGUAGE` varchar(2) default NULL, 
    `AVATAR` varchar(100) default NULL,
    `ICQ` varchar(15) default NULL, 
    `AIM` varchar(255) default NULL, 
    `YIM` varchar(255) default NULL, 
    `MSN` varchar(255) default NULL, 
    `CONFIRM` varchar(10) default NULL,
    `NEW_PASSWORD` varchar(46) default NULL,
    `EMAIL_CONFIRMED` int(11) NOT NULL default '1', 
    `LNAME` varchar(255) default NULL,
    `CITY` varchar(255) default NULL, 
    `STATE` varchar(255) default NULL,
    `DOB` date default NULL,
    `UTYPE` tinyint(1) NOT NULL default '0',
    PRIMARY KEY  (`ID`) 
) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=latin1 
 COMMENT='Stores all the users with informations'

Here is my query:

SELECT count(c.USER_ID) as total_commments_user , 
  c.*, u.NAME, l.TITLE as LINK_TITLE, u.AUTH_IMG
FROM `PLD_COMMENT` c
left outer join `PLD_USER` u ON (u.ID = c.USER_ID) 
left outer join `PLD_LINK` l ON (l.ID = c.ITEM_ID AND l.STATUS='2') 
WHERE c.TYPE = '1' 
  AND c.STATUS = '2' 
group by c.ID ORDER BY c.ID DESC LIMIT 0 , 3

When I run this query I got 1 in each row under total_comments_user.

Any idea?

Answer 1

You need to add all the columns you are selecting in the SELECT clause except the c.USER_ID to the GROUP BY clause, like this:

group by c.ID, c.otherfields, l.title,..

EDIT: I think the following will work properly:

SELECT count(c.USER_ID) as total_commments_user , 
       c.*, u.NAME, l.TITLE as LINK_TITLE, u.AUTH_IMG
FROM `PLD_COMMENT` c 
left outer join `PLD_USER` u ON (u.ID = c.USER_ID) 
left outer join `PLD_LINK` l ON (l.ID = c.ITEM_ID) 
group by c.ITEM_ID, c.USER_ID
ORDER BY c.USER_ID, l.ID 

Example:
If you have the following sample data:

• PLD_LINK:

  ID   STATUS   TITLE    
  1      1      title1
  2      2      title2
  

• PLD_USER:

  ID     NAME
  8    Mahmoud
  9     Ahmed
  

• PLD_COMMENT:

  ID   ITEM_ID USER_ID   STATUS
  4      1        8        1
  5      1        8        1
  6      1        8        1
  7      2        8        2
  8      2        8        2
  9      1        9        1
  10     1        9        1
  

---

Case 1: the user Mahmoud is displayed twice:

Then, the previous query will give you the count of the comments for each User and for each item too, like this:

total_commments_user  ID  ITEM_ID   USER_ID   Name
         3            4      1         8     Mahmoud
         2            7      2         8     Mahmoud
         2            9      1         9      Ahmed

Notice that the user Mahmoud is displayed twice with a different count, becouse he has different Item_Id.

---

Case 2: the user Mahmoud is diplayed only one time:

If you want to get the count of comments for each user for all items then you will need to group by only the USER_ID and you will got:

total_commments_user  ID  ITEM_ID   USER_ID   Name  
         5            4      1         8     Mahmoud
         3            9      1         9      Ahmed

As you can see now the user Mahmoud is displayed only one time, becouse we ingonred Item_Id.

You can then filter by status or what ever.