Join tables horizontally and dynamically - php

I need some help from joining tables horizontally my tables are
+---------+---------+
| Candidates Table |
+---------+---------+
| can_id | Name |
+---------+---------+
| 1 | Liza |
| 2 | Sarah |
| 3 | Jane |
| | |
+---------+---------+
+---------+---------+
| Judges Table |
+---------+---------+
| id | Name |
+---------+---------+
| 1 | judge1 |
| 2 | judge2 |
| 3 | judge3 |
+-------------------+
+---------+---------------+--------+-------+
| Score Table |
+---------+-------+------------------------|
| sco_id | can_id| jud_id |crit_id |score|
+---------+--------+-----------------------+
| 1 | 1 | 2 | 1 | 87 |
| 2 | 1 | 3 | 1 | 89 |
| 3 | 1 | 1 | 1 | 80 |
+------------------------------------------+
I need an output of something like this one..
+---------+---------------+-------------+
| Score board |
+---------+---------+-------------------|
| Name | judge1 | judge2 | judge3 |
+---------+---------+-------------------|
| Liza | 80 | 87 | 89 |
|some data|some data|some data|some data|
|some data|some data|some data|some data|
+---------------------------------------+
notes: crit_id is criteria id from criteria table.
Normally I would use some joins and subqueries but my problems is I need the output dynamically where in if I add a new judges it will automatically generate a new column. I need at least 1 candidate data with all of the judges scores then just loop it with parameters on php to get the other candidates data something like
php loop start
<td>name</td>
<td>judge1 score</td>
<td>judge2 score</td>
php end loop
or if i could get the whole candidates table with judges score much better for me not to loop them per candidate
I've tried to research similar questions like
Concatenate more than two tables horizontally in SQL Server
I've tried to code myself but I got stuck with joining the judges..
SELECT s.sco_id,c.Name,c.Municipalities
FROM `tbl_scoring` s
LEFT JOIN tbl_candidates c ON c.`can_id` = s.`can_id`
WHERE s.can_id = 11
AND crit_id = 1
ORDER BY s.jud_id asc
I need a query that would generate dynamically depending on the number of judges either get candidate data with scores of judge then loop it on php or much way better if i get all the data without looping

Initialize the following arrays:
$judges = [];
$scores = [];
$candidates = [];
Then execute your query, and loop the results. Set those values for each iteration:
$judges[$row['jud_id']] = 1;
$candidates[$row['can_id']] = $row['Name'];
$scores[$row['can_id']][$row['jud_id']] = $row['score'];
Now you want to get the participant judges names, so let's run a SQL query:
$sql = 'SELECT Name FROM judges WHERE id IN (' . implode(',', array_keys($judges)) . ')';
And on every iteration set the judge's name in the $judges array:
$judges[$row['id']] = $row['Name'];
Then for the output:
echo '<tr>';
echo '<td>Name</td>';
ksort($judges);
foreach ($judges as $name) {
echo '<td>Judge: ' . $name . '</td>';
}
echo '</tr>';
foreach ($scores as $candidateId => $data) {
echo '<tr>';
echo "<td>$candidates[$candidateId]</td>";
ksort($data);
foreach ($data as $score) {
echo "<td>$score</td>";
}
echo '</tr>';
}
I used ksort on $judges and $data so the score will fit each judge.

first, we retrieve the judges' ids and name that exist on the score table.
$judges = [];
$query = "SELECT id, name FROM Judges WHERE id IN ( SELECT DISTINCT jud_id FROM Score )";
// execute the query and store the results in the $judges array.
we retrieve the candidates' ids and name that exist on the score table.
$candidates = [];
$query = "SELECT id FROM Candidate WHERE id IN ( SELECT DISTINCT can_id FROM Score )";
// execute the query and store the results in the $candidates array.
then, we join the candidate and score table.
$candidate_score = [];
$query = "SELECT Candidate.name, Candidate.id as candidate_id , Score.jud_id, Score.score FROM Candidate JOIN Score ON Score.can_id = Candidate.id";
// execute the query and store it in the $candidate_score array.
now, for each candidate, we fill its score on the $score_board array.
$score_board = [];
foreach ( $candidates as $candidat )
{
$score_board[$candidat] = [];
foreach ( $judges as $judge )
{
$judge_name = $judge['name'];
$judge_id = $judge['id'];
$score_board[$candidat][$judge_name] = get_judge_score($candidate_score,$candidat,$judge_id);
}
}
this is how the get_judge_score will work:
function get_judge_score ( $scores , $candidate , $judge )
{
$score_filtred = array_filter($scores, function ($score) use ($candidate,$judge) {
return $score['jud_id'] == $judge && $score['candidate_id'] = $candidate;
});
return count($score_filtred) > 0 ? $score_filtred[0]['score'] : 0;
}

Related

Check if a certain element is in a table MySQL database

I need to check if a certain element is in the table.
Table I am using:
+----------+------------+-------------------+
| ClientId | ClientName | ClientCountryName |
+----------+------------+-------------------+
| 1 | Chris | UK |
| 2 | David | AUS |
| 3 | Robert | US |
| 4 | Mike | ENG |
+----------+------------+-------------------+
This is the code I made, is there a better way?
$c=0;
$sql = "SELECT * FROM users";
$result = $conn->query($sql);
while($row = $result->fetch_assoc()) {
if('US'==$row['ClientCountryName']){
$c=$c+1; //If the element is in the table, increment c
}
}
if($c!=0){ //if c is incremented means that the element is one or multiple times in the table
echo 'Element is in the table';
}
else{ //if c is not incremented then the element is not in the table
...
}
You can use count to return count of elements containing US
select count(*)
from users
where ClientCountryName like 'US'
Thanx!

How to query based on multiple relations between columns - MySQL?

I have four columns in a properties table: property_id, value, id, material_id.
I also have an array of properties: Array $properties
The schema is a bit complicated, because I want to find the material_id based on the matching properties.
An example:
$properties = array(['property_id'=>1,'value'=>3],['property_id'=>2,'value'=>6],['property_id'=>3,'value'=>4]);
Example table output:
+----+-------------+-------------+-------+
| id | material_id | property_id | value |
+----+-------------+-------------+-------+
| 1 | 1 | 3 | 5 |
| 2 | 1 | 3 | 5 |
| 3 | 1 | 3 | 5 |
| 4 | 2 | 1 | 3 |
| 5 | 2 | 2 | 6 |
| 6 | 2 | 3 | 4 |
| 10 | 4 | 1 | 9 |
| 11 | 4 | 2 | 3 |
| 12 | 4 | 3 | 6 |
+----+-------------+-------------+-------+
Now, I need material_id that satisfies all the properties. How can I do that..? Do I need to use exist statement of MySQL?
Now, for each element in your array you will want to run a statement that looks like this:
SELECT material_id FROM properties WHERE property_id = 2 AND value = 3;
Do you need help on the php code also? You could run a for each loop, but I will need to know what way you are using to communicate with your database for more specifics.
edit
foreach ($properties as $foo => $bar)
{
$sql = 'SELECT material_id FROM properties WHERE ';
foreach ($bar as $key => $value)
{
$sql .= $key .' = '. $value .' AND ';
}
$sql .= 'true';
*run your PDO code on $sql here*
}
On behalf of performance, it's not a good idea to run a query per array's value. If you have an oversized array things can get pretty slower.
So, best solution can be to build a single query including all conditions presented on $properties array:
<?php
$properties = array(['property_id'=>1,'value'=>3],['property_id'=>2,'value'=>6],['property_id'=>3,'value'=>4]);
$qCondition = [];
foreach($properties as $prop) {
$q = sprintf("(property_id = %d AND value = %d)", $prop["property_id"], $prop["value"]);
$qCondition[] = $q;
}
// assuming that your database table name is 'materials'
$sql = sprintf("SELECT * FROM materials WHERE (" . implode(" OR ", $qCondition) . ")");
echo $sql;
Result:
SELECT * FROM materials
WHERE ((property_id = 1 AND value = 3) OR (property_id = 2 AND value = 6) OR (property_id = 3 AND value = 4))
Therefore, you need to run only one single query to get all desired rows.
You can play with suggested solution here: http://ideone.com/kaE4sw

Count same values in different column mysql

I need to count how many times in ripeted the same values in different columns for the same id..
I'll try to clarify with an example:
TABLE:
+-----+-----+-----+-----+-----+
| id | d01 | d02 | d03 | d04 |
+=====+=====+=====+=====+=====+
| 1 | A | A | B | B |
+-----+-----+-----+-----+-----+
| 2 | A | A | A | A |
+-----+-----+-----+-----+-----+
| 3 | B | B | A | A |
+-----+-----+-----+-----+-----+
| 4 | A | A | A | A |
+-----+-----+-----+-----+-----+
| 5 | A | A | A | A |
+-----+-----+-----+-----+-----+
| 6 | B | A | A | A |
+-----+-----+-----+-----+-----+
I need to know how many times the value "B" is repeating for any person (ID)..
Is that possible to do that? RESULTS
+-----+-----+-----+
| id | count B |
+=====+=====+=====+
| 1 | 2 |
+-----+-----+-----+
| 2 | 0 |
+-----+-----+-----+
| 3 | 2 |
+-----+-----+-----+
I was thinking to use the function "SUM" but I have no idea how to display just the single ID.
Thanks in advance, hope the question is clear enough!
If there are only four columns:
SELECT id, (d01 = 'B') + (d02 = 'B') + (d03 = 'B') + (d04 = 'B')
FROM tablename
No there are 31 columns
That's a problem which you can solve in two ways:
Repeat the condition for the other 27 columns :)
Normalize your structure so that each value is dependent on both the id and a numeric value that represents a calendar.
The PHP way
You can also fetch all columns and let PHP solve this for you:
$res = $db->query('SELECT * FROM tablename');
foreach ($res->fetchAll(PDO::FETCH_ASSOC) as $row) {
$id = $row['id'];
unset($row['id']); // don't count the id column
$count = count(array_keys($row, 'B', true));
printf("ID %d: %d\n", $id, $count);
}
Since you seem to be using mysql_*:
// SHOW COLUMNS returns all the columns and constrains of the defined table
// We only need the column names so we will be later calling it by 'Field'
$sql = mysql_query("SHOW COLUMNS FROM table"); //your table name here
$val_to_count = 'B'; //value to count here
$id = 1; //id to search for
$new_sql = 'SELECT id, ';
// In this loop we will construct our SELECT query using the columns returned
// from the above query
while($row=mysql_fetch_array($sql)){
if($row['Field']!='id'){
$new_sql .= ' ('.$row['Field'].' = "'.$val_to_count.'") + ';
}
}
//Removing the last "+ " produced in the select query
$new_sql = rtrim($new_sql,"+ ");
$new_sql .= ' as count FROM table WHERE id = '.$id; //table name here again
// so $new_sql now has an output like:
// SELECT ID, (d01 = 'B') + (d02 = 'B') ... WHERE id = 1
$sql2 = mysql_query($new_sql);
//executing the constructed query with the output below
while($row2=mysql_fetch_array($sql2)){
echo 'ID - '.$row2['id']."<br>";
echo 'Count - '.$row2['count']."<br>";
}
Note:
mysql_* is deprecated, please consider to migrate to mysqli_*

confusion about result structure from joining tables when each row has multiple correspondence on the second table

lets say i have a simple poll aplication
and each user only can choose one option from poll
my poll table
+-----------+---------------------+
| poll_id | question |
+-----------+---------------------+
| 1 | q1? |
+-----------+---------------------+
| 2 | q2? |
+-----------+---------------------+
| 3 | q3? |
+-----------+---------------------+
my options table
+-----------+---------------------+---------+---------+
| option_id | poll_id | option | counter |
+-----------+---------------------+---------+---------+
| 1 | 1 | yes | 254 |
+-----------+---------------------+---------+---------+
| 2 | 1 | no |392333337|
+-----------+---------------------+---------+---------+
| 3 | 2 | yes | 1000 |
+-----------+---------------------+---------+---------+
right now i do something like this to show all the polls i one page
$polls = $db->query("select * from polls ");
foreach ($polls as $poll)
{
echo $poll->question;
$options = $db->query("select * from options where poll_id = '$poll->id' ");
foreach($options as $op )
{
echo '<checkbox />'.$op->option;
}
}
now if i want to do this using joine and one query
$query = "select p.* , o.* from polls p JOIN options o ON p.poll_id = o.poll_id ";
what data structure is going to be used to represent the result ? perhaps a multidimensional array ? i'm not sure how can i printout the result
like in this example result is going to be
resul_array (
poll_id poll_question option option
1 q1 ys no
2 q2 no
}
if i get the result as an array row one would have columns with similar name ? i'm confused
In my opinion, you just need to add "order by" in your query, and store result in an array, and then process the logic on it.
Something like:
$polls = $db->query("select p.* , o.* from polls p JOIN options o ON p.poll_id = o.poll_id order by p.poll_id");
$currentPoll = $polls[0];
foreach ($polls as $poll)
{
if($poll->poll_id != $currentPoll->poll_id) {
echo $poll->question;
$currentPoll = $poll;
}
echo '<checkbox />'.$poll->option;
}
HTH.

PHP and MySQL, array associated with 2 keys

I have this scenario.
I input $groupid="1";
main table
----------------------
| groupid | postid |
|---------------------|
| 1 | 1 |
| 2 | 2 |
| 1 | 3 |
$query = "SELECT postid FROM `mainl` WHERE groupid='$groupid'";
$result = mysql_query($query);
// a group of postids belonging to that groupid which should hold [1, 3] for groupid=1
while($row = mysql_fetch_array($result)) {
$postids[] = $row["postid"];
}
second table
-------------------------------------------
| postid | commentid | comment |
-------------------------------------------
| 1 | 1 | testing 1 |
| 1 | 2 | testing 2 |
| 1 | 3 | what? |
| 2 | 1 | hello |
| 2 | 2 | hello world |
| 3 | 1 | test 3 |
| 3 | 2 | begin |
| 3 | 3 | why? |
| 3 | 4 | shows |
$query = "SELECT * FROM `second`";
$result = mysql_query($query);
while ($row = mysql_fetch_array($result)) {
if (in_array($row["postid"], $postids)) {
$comments[$row["postid"]] = $row["comment"];
But how should I take care of commented
I want the postid array to be [1,3] and my comment array to be
[commentid: comment] [1:testing1, 2: testing2, 3: what?] for postid=1
and
[1:test3, 2:begin, 3: why? 4:shows] for postid=3
how should be arrange everything such comment are associated with commentid and postid?
First I would follow rokdd suggestion and make 1 query
SELECT m.groupid , s.postid, s.commentid, s.comment FROM `main1` m JOIN `second` s USING (postid) where m.groupid = 1
Then I would make a multi-dimensional array
while ($row = mysql_fetch_array($result))
$groups[$row['groupid'][$row['postid']][$row['commentid']=$row['comment'];
then to iterate through the array
foreach($groups as $group)
foreach($group as $post)
foreach($post as $comment)
echo $comment;
This will keep track of groups also (if you ever want to select by more than 1 group.
If you don't care about groups just drop off the first part of the array.
while ($row = mysql_fetch_array($result))
$posts[$row['postid']][$row['commentid']=$row['comment'];
foreach($posts as $post)
foreach($post as $comment)
echo $comment;
I guess to use the join in sql so that you will have one statement:
SELECT * FROM second as second_tab LEFT join main as main_table ON main_table.post_id=second_table.post_id WHERE main_table.group_id="3"
Well not tested now but thats a way to solve some of your problems!

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