PHP MYSQL - ID AS category SUB_ID as Comment - php

I cant figure out how to get comments underneath mysql db entries..
For example There is one article witch id is 1 and then there are some (for example 3) comments in that article (ID - 1) [ARTICLE_ID][CATEGORY]
And the comments are like: [ID][ARTICLE_ID]
..
so it is like
| ID | SUB_ID | TITLE....
| 1 | 123 | THIS IS A ARTICLE
| 2 | 1 | COMMENT TO ARTICLE 1
| 3 | 1 | COMMENT 2 to article 1
| 4 | 1 | Comment 3 to Article 1
AND CEN_TYPE for all of thesese IDs, 1,2,3,4 is forumentry
I've tryed like this:
SELECT everthing from CNT_Entries_A WHERE CEN_TYPE is like forumentry - so everthing is fine here, but it doesnt put comments underneath (logically)
Putting all ID's AND SUB_ID's in to a array's
making foreach cycle, inside that checking if current ID is equal to arrays value if it is, check if that ID is in array - if is not then printing it out and putting it to an array..
SAME THING to SUB ID

I highly recommend to split the data into two data tables:
Articles
article_id | text
Comments
comment_id | article_id | comment
Then You won't have problem to do a simple SELECT + LEFT JOIN query...

This will give result as article and their comments so that u can then loop over:
find the implementation here
SELECT c1 . * , c2 . *
FROM comments AS c1
JOIN comments AS c2 ON ( c1.id = c2.sub_id
AND c1.id != c2.id )
WHERE c1.cen_type = 'forumentry'
+----+--------+-------------------+------------+----+--------+----------------------+------------+
| id | sub_id | title | cen_type | id | sub_id | title | cen_type |
+----+--------+-------------------+------------+----+--------+----------------------+------------+
| 1 | 1 | THIS IS A ARTICLE | forumentry | 2 | 1 | COMMENT TO ARTICLE 1 | forumentry |
| 1 | 1 | THIS IS A ARTICLE | forumentry | 3 | 1 | COMMENT 2 to article | forumentry |
| 1 | 1 | THIS IS A ARTICLE | forumentry | 4 | 1 | Comment 3 to Article | forumentry |
+----+--------+-------------------+------------+----+--------+----------------------+------------+

Related

is it safe to run a another query in side a mysql loop

I have a left join query to get posts liked by a users. if 2nd logged in user visit the 1st user profile will show the likes by 1st user and also will show a text on the post if 2nd user (logged in user) like the same post
user table
user_id | username
likes table
like_id | post_id | uid
MySQL
$SQL = "SELECT * FROM likes LEFT JOIN users ON users.user_id = likes.uid WHERE likes.uid = 'user1'"
If i run another query inside the while loop of above query it will work
$check_id = row['post_id']; //get post id from 1st loop
if(isset($_SESSION['userid'])){
$check = "SELECT * FROM likes WHERE post_id='$check_id' AND uid='LOGED-IN-USER-ID'"
}
Then i can get the num_rows and add text. This work perfectly fine but i like to know is there a better way to do this without running so many queries inside the while loop. Is there a way to combine the queries or do the 2nd query outside of the loop.
That's "safe" from "data consistency point of view", but querying in a while after a query is called a "1+N" and is typically a performance killer, you may easily find documentation about SQL 1+N problem.
The solution is to let the SQL server do the job for you in a single query, avoiding playing ping pong with it (read: TCP packets back-and-forth, query parsing, ...).
Given:
> SELECT * FROM user;
+---------+----------+
| user_id | username |
+---------+----------+
| 1 | root |
| 2 | user2 |
| 3 | user3 |
+---------+----------+
> SELECT * FROM `like`;
+---------+---------+---------+
| like_id | post_id | user_id |
+---------+---------+---------+
| 1 | 1 | 1 |
| 2 | 2 | 1 |
| 3 | 3 | 1 |
| 4 | 4 | 1 |
| 5 | 2 | 2 |
+---------+---------+---------+
> SELECT * FROM `post`;
+---------+--------+
| post_id | text |
+---------+--------+
| 1 | post 1 |
| 2 | post 2 |
| 3 | post 3 |
| 4 | post 4 |
+---------+--------+
There's multiple way to request what you want, but one way may be:
> SELECT like_id, like.post_id, text,
(SELECT 1 FROM `like`
WHERE post_id = post.post_id AND
user_id = 2 /* logged in user */) AS I_like_it_too
FROM `like`
JOIN post USING (post_id)
WHERE user_id = 1 /* user id of seen profile */;
+---------+---------+--------+---------------+
| like_id | post_id | text | I_like_it_too |
+---------+---------+--------+---------------+
| 1 | 1 | post 1 | NULL |
| 2 | 2 | post 2 | 1 |
| 3 | 3 | post 3 | NULL |
| 4 | 4 | post 4 | NULL |
+---------+---------+--------+---------------+
The use the I_like_it_too alias to display post differently as needed.
From a performance point of view you'll need an index on like.user_id to restrict the selected rows on a little subset, the dependent subquery will only be ran for this subset, so that's OK.
Another possibility may be:
> SELECT displayed.like_id, displayed.post_id, text, my_likes.like_id is not null AS i_also_like
FROM `like` AS displayed
JOIN post USING (post_id)
LEFT JOIN `like` AS my_likes ON
displayed.post_id = my_likes.post_id AND
my_likes.user_id = 2 /* logged user */
WHERE displayed.user_id = 1 /* user id of seen profile */;
+---------+---------+--------+-------------+
| like_id | post_id | text | i_also_like |
+---------+---------+--------+-------------+
| 1 | 1 | post 1 | 0 |
| 2 | 2 | post 2 | 1 |
| 3 | 3 | post 3 | 0 |
| 4 | 4 | post 4 | 0 |
+---------+---------+--------+-------------+
Do u mean like this ?
Table SO_LIKES ( ur "Like" Table )
like_id | post_id | uid
1 | 1 | 1
2 | 2 | 1
3 | 1 | 2
Table SO_USERS ( ur "Users" Table )
user_id | username
1 | User1
2 | User2
SQL
SELECT * FROM SO_LIKES as t1 LEFT JOIN SO_USERS as t2 ON t1.uid = t2.user_id INNER JOIN SO_LIKES as t3 ON t1.post_id = t3.post_id WHERE t2.user_id = 1 AND t3.uid = 2
SO Simply call the Same Table in ur query again and use the ID of user 2 there
WHERE t2.user_id = 1 AND t3.uid = 2
Output Looks then like this
like_id | post_id | uid | user_id | username | like_id | post_id | uid
1 | 1 | 1 | 1 | User1 | 3 | 1 | 2
SO u get the POST_id 1 That both Users has Liked

for each value of one table get and display count number of coresponding values from another table

unfortunately i have to do this in mysql / php . I looked for three days, and there is like 10.000 explantions of this but NONE (and I repeat NONE) works for me. I tried it all. I have to ask, sorry.
I have two tables - articles and control.
table "articles"
------------------
art_id | name |
------------------
1 | aaa |
2 | bbb |
3 | ccc |
4 | ddd |
table "control"
--------------------------------------------
con_id | art_id | data |
--------------------------------------------
1 | 1 | something-a |
2 | 2 | something-b |
3 | 1 | something-a |
4 | 2 | something-c |
5 | 3 | something-f |
art_id exists in both tables. Now what i wanted - for query:
"select * from articles order by art_id ASC" displayed in a table
to have also one cell displaying the count for each of art_id's from table CONTROL...
and so i tried join, left join, inner join - i get errors ... I also tried for each get only one result (for example 2 for everything)... this is semi-right but it displays the array of correct results and it's not even with join!!! :
$query = "SELECT art_id, count(*) as counting
FROM control GROUP BY art_id ORDER BY con_id ASC";
$result = mysql_query($query);
while($row=mysql_fetch_array($result)) {
echo $row['counting'];
}
this displays 221 -
-------------------------------------------------
art_id | name | count (this one from control) |
-------------------------------------------------
1 | aaa | 221 |
2 | bbb | 221 |
3 | ccc | 221 |
and it should be:
for art_id(value1)=2,
for art_id(2)=2,
for art_id(3)=1
it should be simple - like a count of values from CONTROL table displayed in query regarding the "articles" table...
The result query on page for table articles should be:
"select * from articles order by art_id ASC"
-------------------------------------------------
art_id | name | count (this one from control) |
-------------------------------------------------
1 | aaa | 2 |
2 | bbb | 2 |
3 | ccc | 1 |
So maybe i should go with JOIN or with join plus for each... Tried tha too, but then i'm not sure what is the proper thing to echo... all-in-all i'm completely lost here. Please help. Thank you.
So imagine this in two steps:
Get the counts per art_id from the control table
Using your articles table, pick up the counts from step 1
That will give you a query that looks like this:
SELECT a.art_id, a.name, b.control_count
FROM articles a
INNER JOIN
(
SELECT art_id, COUNT(*) AS control_count
FROM control
GROUP BY art_id
) b
ON a.art_id = b.art_id;
Which will give you the results you're looking for.
However, instead of using a subquery, you can do it all in one shot:
SELECT a.art_id, a.name, COUNT(b.art_id) AS control_count
FROM articles a
INNER JOIN control b
ON a.art_id = b.art_id
GROUP BY a.art_id, a.name;
SQL Fiddle demo
SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id DESC;
If I understood your question right, this query should do the trick.
Edit: Created the tables you have described, and it works.
SELECT * FROM articles;
+--------+------+
| art_id | name |
+--------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
| 4 | ddd |
+--------+------+
4 rows in set (0.00 sec)
SELECT * FROM control;
+--------+--------+------+
| con_id | art_id | data |
+--------+--------+------+
| 1 | 1 | NULL |
| 2 | 2 | NULL |
| 3 | 1 | NULL |
| 4 | 2 | NULL |
| 5 | 3 | NULL |
+--------+--------+------+
5 rows in set (0.00 sec)
SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id ASC;
+--------+------+----------------+
| art_id | name | count_from_con |
+--------+------+----------------+
| 1 | aaa | 2 |
| 2 | bbb | 2 |
| 3 | ccc | 1 |
| 4 | ddd | 0 |
+--------+------+----------------+
You haven't quite explained what you want to accomplish with the print out but here is an example in PHP: (Use PDO instead of mysql_)
$pdo = new PDO(); // Make your connection here
$stm = $pdo->query('SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id ASC');
while( $row = $stm->fetch(PDO::FETCH_ASSOC) )
{
echo "Article with id: ".$row['art_id']. " has " .$row['count_from_con'].' connected rows in control.';
}
Alternatively with the mysql_ extension:
$result = mysql_query('SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id ASC');
while( $row = mysql_fetch_assoc($result) )
{
echo "Article with id: ".$row['art_id']. " has " .$row['count_from_con'].' connected rows in control.';
}
This should be enough examples to help you accomplish what you need.

Query mysql when reach row then stop? show the queue number

I am doing a script want to calculate how many row record before an user record when t1.status is 1.
My table is t1, and the data as below:
+------+---------+------------+----------+----------+
| ID | name | desc | status | time |
+------+---------+------------+----------+----------+
| 1 | ABB | | 1 | 0325 |
| 2 | CCD | | 1 | 0236 |
| 3 | EEF | | 1 | 0325 |
| 4 | GGG | | 1 | 0000 |
| 5 | HIJ | | 2 | 1234 |
| 6 | KKK | | 1 | 5151 |
+---------------------------------------------------+
I was thinking about the query is something like (query row where status = 1 AND stop when reach $userid)
I would like to output to show user (Let's say username is GGG) as:
$userid = 'GGG';
then my output will be
<table><tr><td>Queue: GGG You came in 4 place, in front of you still got 3 person in queue, please be patient</td></tr></table>
How to I do the right query to get the number 4 and 3 ?
Thank you.
You can try something like this hope it helps :-
SELECT count(*) as COUNT FROM t1 WHERE id < (SELECT id FROM t1 WHERE userid = $userid)

Select foreign key (group) where is the biggest match

I have three tables group_sentences, group_sentences_attributes and group_senteces_categories.
I have an attributes array which I am using in query with IN (after implode).
Then I have one category ID because they are stored recursively, so no need for an array.
I need to select one group number where is the biggest match for $attributesArray and of course category too.
Here is table group_sentences_attributes
+-----+-------+-----------+
| id | group | attribute |
+-----+-------+-----------+
| 1 | 1 | 3564 |
| 2 | 1 | 3687 |
| 3 | 1 | 3689 |
| 4 | 2 | 3687 |
| 5 | 2 | 3564 |
+-----+-------+-----------+
Here is group_sentences_category
+-----+-------+----------+
| id | group | category |
+-----+-------+----------+
| 1 | 1 | 1564 |
| 2 | 1 | 1221 |
| 3 | 1 | 1756 |
| 4 | 2 | 1358 |
| 5 | 2 | 1125 |
+-----+-------+----------+
Here is my query, but I am afraid that it won't do the job done.
SELECT group_categories.group
FROM group_categories, group_attributes
WHERE group_categories.category = '$category'
AND group_attributes.attribute IN ($attributesArray)
GROUP BY group_categories.group
ORDER BY count(group_attributes.attribute)
Any help would be appreciated, thanks.
First, the table in your query do not match the tables in the question. I am guessing they are simply missing the "sentence". Then, you have no join clause. Simple rule: Never use commas in the from clause.
group is a lousy name for a column, because it is a keyword in SQL. The following may be what you are looking for:
SELECT gc.groupid
FROM group_sentences_attributes sa JOIN
group_sentences_category sc
ON sa.groupid = sc.groupid
WHERE sc.category = '$category' AND
sa.attribute IN ($attributesArray)
GROUP BY sa.groupid
ORDER BY count(sa.attribute);
If you only want one row, then add LIMIT 1 to the end.

how to merge multiple rows with same id mysql

I'm new posting here but the community have been my best resource on my projects so far.
I'm a dumb/dummy Mysql "wanna be" and I'm in the middle of a project that is making me go mad.
I have a table from wordpress plugin buddypress that pairs meta_key and meta_values in order to create something akin to a taxonomy. My duty is to use these paired values to implement an advanced group search. Here is the original table:
--------------------------------------------
id | group_id | meta_key | meta_value
--------------------------------------------
1 | 1 | time-zone | Kwajalein
2 | 1 | playstyle | hardcore
3 | 1 | recruiting-status | Open
4 | 1 | ilvl | 115
5 | 1 | main-raid | Final Coil of Bahamut
6 | 1 | voicechat | fc.teamspeak3.com
etc....
Using a view I managed to create a more friendly searchable table for begginers :
gid| time-zone| playstyle | main-raid
--------------------------------------------
1 | | |
1 |Kwajalein | |
1 | | hardcore |
1 | | |
1 | | | Final Coil of Bahamut
1 | | |
And here is the view code:
SELECT distinct
group_id AS 'gid',
IF(meta_key='recruiting-status',meta_value,'') AS 'Recruitment',
IF(meta_key='server',meta_value,'') AS 'server',
IF(meta_key='time-zone',meta_value,'') AS 'tzone',
IF(meta_key='main-raid',meta_value,'') AS 'raid',
IF(meta_key='raid-days',meta_value,'') AS 'days',
IF(meta_key='playstyle',meta_value,'') AS 'playstyle',
IF(meta_key='raid-progression',meta_value,'') AS 'progression',
IF(meta_key='raid-time',meta_value,'') AS 'time',
IF(meta_key='tanker-spot',meta_value,'') AS 'tank',
IF(meta_key='healer-spot',meta_value,'') AS 'healer',
IF(meta_key='melee-dps-spot',meta_value,'') AS 'melee',
IF(meta_key='ranged-dps-spot',meta_value,'') AS 'ranged',
IF(meta_key='magic-dps-spot',meta_value,'') AS 'magic',
IF(meta_key='ilvl',meta_value,'') AS 'ilvl',
IF(meta_key='voicechat',meta_value,'') AS 'voice',
IF(meta_key='voicechatpass',meta_value,'') AS 'voicep',
FROM wpstatic_bp_groups_groupmeta
The point is, I need to merge that result (view) so all the group_id=1 or 2 or 3, etc stand in one single row, like this:
gid| time-zone| playstyle | main-raid
--------------------------------------------
1 |Kwajalein | hardcore | Final Coil of Bahamut
2 |SaoPaulo | regular | Second Coil of Bahamut
etc
Can anyone help me there?
Just surround your IFs in a MAX, or another aggregate function that will capture the non-empty strings (e.g., GROUP_CONCAT), and add a GROUP BY group_id add the end. For example,
SELECT
group_id AS gid,
MAX(IF(meta_key='recruiting-status',meta_value,'')) AS 'Recruitment',
MAX(IF(meta_key='server',meta_value,'')) AS 'server',
...
FROM wpstatic_bp_groups_groupmeta
GROUP BY group_id

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