Issue in query with inner join and concat() operation in mysql - php

I have two tables:
sk_accounts //details of user
acnt_user_id
acnt_fname //first name
acnt_lname
acnt_profile_picture
acnt_member_class
so on........
sk_following //table containing details of users who are following others
id
flwing_follower_id //id of the user who are followed by other followers
flwing_following_user_id
following_date
I want to display details of the follower based on the following Mysql code.Unfortunately it returns zero rows eventhough there are 3 rows.My query is like this:
$query_following = "SELECT sk_following.flwing_following_user_id,
sk_accounts.acnt_fname,
sk_accounts.acnt_lname,
sk_accounts.acnt_member_class,
sk_accounts.acnt_profile_picture
FROM sk_following
INNER JOIN sk_accounts
WHERE sk_following.flwing_follower_id='$id' AND sk_accounts.acnt_user_id=sk_following.flwing_following_user_id AND CONCAT(sk_accounts.acnt_fname,' ',sk_accounts.acnt_lname)='$name'";
$result_following = mysql_query($query_following);
$count_following = mysql_num_rows($result_following);
echo $count_following;
Note:$id and $name contain values
Kindly help me.Thanks in advance.

Try this,
"SELECT sk_following.flwing_following_user_id,
sk_accounts.acnt_fname,
sk_accounts.acnt_lname,
sk_accounts.acnt_member_class,
sk_accounts.acnt_profile_picture
FROM sk_following
LEFT JOIN sk_accounts ON sk_accounts.acnt_user_id=sk_following.flwing_following_user_id
WHERE sk_following.flwing_follower_id='$id'
AND CONCAT(sk_accounts.acnt_fname,' ',sk_accounts.acnt_lname)='$name'";
may this help you.

Hard to completely understand without seeing sample data and desired output, but should your JOIN be on the flwing_follower_id and not the flwing_following_user_id?
SELECT sk_following.flwing_following_user_id,
sk_accounts.acnt_fname,
sk_accounts.acnt_lname,
sk_accounts.acnt_member_class,
sk_accounts.acnt_profile_picture
FROM sk_following
INNER JOIN sk_accounts ON sk_accounts.acnt_user_id=sk_following.flwing_follower_id
WHERE sk_following.flwing_follower_id='$id'
AND CONCAT(sk_accounts.acnt_fname,' ',sk_accounts.acnt_lname)='$name'
Good luck.

Related

How to user SQL two table field.? PHP

Here I want to access two table field but I cant get success. Here is my little code. please check that. I want to access Analysis.Right and tabl3.right.
I am printing its with foreach loop. like $res['Right'] of Analysis and $res['right'] of tabl3. when I try to print this it's show me error
Undefind index Right.
any one can help me
$qry = "select Analysis.Q_Id, tabl3.Q_Id, Analysis.Right, tabl3.right from tabl3 INNER JOIN Analysis ON Analysis.Q_Id = tabl3.Q_Id where Analysis.Q_Id = 3";
please help..
you have tow column with right name related to different table so there is not a column name right but 'Analysis.Right ' or 'tabl3.right'
or you can assign an alias for set the column name equalt to Right where you need .. eg:
$qry = "select
Analysis.Q_Id
, tabl3.Q_Id
, Analysis.Right as Right
, tabl3.right as Right_t3
from tabl3
INNER JOIN Analysis ON Analysis.Q_Id = tabl3.Q_Id where Analysis.Q_Id = 3";
Your result set has columns with the same name. Give them different names:
select t3.Q_Id, a.Right as a_right, t3.right as t3_right
from tabl3 t3 inner join
Analysis a
on a.Q_Id = t3.Q_Id
where a.Q_Id = 3;
When you look for the names in your code, look for a_right and t3_right.
Note that you don't need to return Q_Id twice. The ON clause guarantees that the values are the same.

Left Join between two databases using PDO

I have two databases and I am trying to compare two tables. My code does not seem to be working, not sure what I am doing wrong.
Here is the code.
<?php
include 'connection.php';
/*
* This code compares between two tables
*/
//SQL call
$getData = $connection->prepare("SELECT `CustomerCity` FROM `auth` LEFT JOIN `tb_data.cobs.city` WHERE `CustomerCity` = `tb_data.cobs.city` LIMIT 3");
$getData->execute();
$gotData = $getData->fetchAll(PDO::FETCH_ASSOC);
print_r($gotData);
In my database I have two tables, on is cobs, the other is tb_data. tb_data has a table called cobs and auth is a table within a database called d_data. Both of these tables have a city column. I need get every record in auth that has a city that matches in the cobs table.
That looks like the query is using a mixture of explicit join syntax with obsolescent syntax for the join using the WHERE clause for the join conditions.
If so try:-
SELECT CustomerCity
FROM auth
LEFT JOIN tb_data.cobs
ON auth.CustomerCity = cobs.city
LIMIT 3
Others have pointed out that your query is wrong, but have not provided a correct answer. This is what you are likely looking for:
SELECT `auth.CustomerCity` FROM `auth`
LEFT JOIN `tb_data.cobs` ON `tb_data.cobs.city` = `auth.CustomerCity`
LIMIT 3
Try this :
Select *.auth, *.cobs from auth join cobs on auth.city = cobs.city limit 3
The query is incorrect, you need to specify the link betweeen the tables auth and tb_data.cobs.city. For example:
SELECT
*
FROM
FOOTABLE FOO
LEFT JOIN
BARTABLE BAR ON BAR.FOO_ID FOO.ID = -- here goes the link between them
WHERE
...

mysql How To join 2 column value into 2 column value

I have two tables with columns as follows:
khs (id, year, program, codemk)
subjects (id, year, program, codemk,namemk, tm, pr, lp)
I want to have a result containing:
codemk, namemk, tm, pr, lp
Note: Fields year, program and codemk in khs table each is not unique also in subjects table. But combine the 3 value of those fields make a unique value.
I tried this:
SELECT khs.id khs.codemk, subjects.namemk, subjects.tm, subject.pr, subjects.lp
FROM khs
RIGHT JOIN subjects
ON khs.year + khs.program +khs.codemk = subjects.year + subjects.program + subjects.codemk;
but the result for tm, pr and lp is not what I expected. What am I missing? Sorry I am new to MySQL and how do i create it to new table view.
Thanks in advance.
Maybe this:
SELECT khs.id khs.codemk, subjects.namemk, subjects.tm, subject.pr, subjects.lp
FROM khs
RIGHT JOIN subjects
ON khs.year=subjects.year, khs.program =subjects.program, khs.codemk = subjects.codemk;
But not sure if that is what you asked, otherwise:
SELECT khs.id khs.codemk, subjects.namemk, subjects.tm, subject.pr, subjects.lp
FROM khs
RIGHT JOIN subjects
ON CONCAT(khs.year,khs.program, khs.codemk) = CONCAT(subjects.year, subjects.program, subjects.codemk);
Why use a join? Why not try something like this:
SELECT codemk,namemk,tm,pr,lp
FROM khs,subjects
WHERE khs.year = subjects.year
I am not sure what is your result expectetions (could you provide it please? as well as samples of data tables) but you can try for now:
SELECT khs.id khs.codemk, subjects.namemk, subjects.tm, subject.pr, subjects.lp
FROM khs
INNER JOIN subjects
ON khs.year = subjects.year
AND khs.program = subjects.program
AND khs.codemk = subjects.codemk;

Mysql query working from command line but only half working in PHP

I have two tables
1.owners
id
firstname
lastname
2.product
id
id2
id3
item
SELECT * FROM owners LEFT JOIN product ON product.id=owners.id where firstname='Jezebel';
Works fine from the command line returning all relevant items from owners and product but using the following PHP
$result = mysql_query("SELECT * FROM owners LEFT JOIN product ON product.id=owners.id where firstname='".$_POST['fname']."'")
only returns results from the table owners.
I have googled extensively and don't see anyone else with this problem.
$fname= $_POST['fname'];
$result = mysql_query("SELECT * FROM owners LEFT JOIN product ON product.id=owners.id where firstname='$fname'")
First, make your query similar to this
$query = sprintf("SELECT * FROM owners LEFT JOIN product ON product.id=owners.id where firstname='%s'",mysql_real_escape_string(trim($_POST['fname'])));
$result = mysql_query($query) or die(mysql_error());
var_dump(mysql_fetch_assoc($result));
and let me know the result so I can update this answer.
First of all: You have two table which match on autoincrement column id?
However, try this?
SELECT tb1.id, tb1. firstname, tb1.lastname, tb2.id, tb2.id2, tb2.id3, tb2.item FROM owners AS tb1 LEFT JOIN product AS tb2 ON tb2.id=tb1.id where tb1.firstname=$fname
I have found the error. It was nothing to do with the select statement. I had a typo in the display code. It should have been like this
echo "</td><td>";
echo $row['id3'];
But was like this instead
echo "</td></td>";
echo $row['id3'];
Thank you all for your help.

Returning data from multiple tables in one query even if secondary tables do not apply

I have an issue getting data from three tables, which I want to return using one query.
I've done this before using a query something like this one:
$query = mysql_query("SELECT
maintable.`id`,
maintable.`somedata`,
maintable.`subtable1_id`,
subtable1.`somedata`,
subtable1.`subtable2_id`,
subtable2.`somedata`
FROM
`maintable` maintable,
`subtable1` subtable1,
`subtable2` subtable2
WHERE
maintable.`somedata` = 'some_search' AND
subtable1.`id` = maintable.`subtable1_id` AND
subtable2.`id` = subtable1.`subtable2_id`
")or die(mysql_error());
The problem this time is that the extra details might not actually apply. I need to return all results that match some_search in maintable, even if there is no subtable1_id specified.
I need something that will go along the lines of
WHERE
maintable.`somedata` = 'some_search'
AND IF maintable.`subtable1_id` IS NOT NULL (
WHERE subtable1.`id` = maintable.`subtable1_id` AND
subtable2.`id` = subtable1.`subtable2_id`
)
As you will probably guess, I am not an advanced mysql user! Try as I might, I cannot get the syntax right, and I have had no luck searching for solutions on the web.
Any help much appreciated!
It seems like the basic distinction you're looking for is between an INNER JOIN and a LEFT JOIN in MySQL.
An INNER JOIN will require a reference between the two tables. There must be a match on both sides for the row to be returned.
A LEFT JOIN will return matches in both rows, like an INNER, but it will also returns rows from your primary table even if no rows match in your secondary tables -- their fields will be NULL.
You can find example syntax in the docs.
If I got this right, you need to use MySQL LEFT JOIN. Try this:
SELECT
m.id,
m.somedata,
m.subtable1_id,
s1.somedata,
s1.subtable2_id,
s2.somedata
FROM
maintable m
LEFT JOIN
subtable1 s1
ON
m.subtable1_id = s1.id
LEFT JOIN
subtable2 s2
ON
s1.subtable2_id = s2.id
WHERE
m.somedata = 'some search'
This will return the data of maintable even if there's no equivalent data in subtable1 or 2 OR data of maintable and subtable1 if there's no equivalent data in subtable2.
How about this:
WHERE
maintable.`somedata` = 'some_search'
AND (maintable.`subtable1_id` IS NULL OR (
subtable1.`id` = maintable.`subtable1_id` AND
subtable2.`id` = subtable1.`subtable2_id` )
)
Keep in mind that this will result in a cross product of subtable1 and subtable2 with maintable when subtable1_id is NULL.

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