I'm trying to do 2 things.
1) Get the amount of rows in this query
SELECT
COUNT(*)
FROM
`my_table`
WHERE
`column_1` = 152
AND
`column_2` = 42
ORDER BY
`column_3`
As you can see that is no problem ^^
2) Determine the number within the range of rows that is returned by id
Ex: ID 765 is Item 4 of 7 where column_1 = 152 and column_3 = 42
Does anyone have any basic solutions to this problem with almost pure MySQL? I'd like to avoid iterating through all the rows and setup a counter to increment until it matches current id like this:
$sql = '
SELECT
*
FROM
`my_table`
WHERE
`column_1` = 152
AND
`column_2` = 42
ORDER BY
`column_3`
';
$query = mysqli_query($sql);
$current_id = 2523;
$i = 1;
while ($row = mysqli_fetch_assoc($query)) {
if ($row['id'] == $current_id) {
$current_position = $i;
}
$i++;
}
print 'Current position in range is: '. $current_position;
Also please don't worry about the actual syntax, I won't be using this exact script, but you get the logic that I'd like to avoid using. If anyone has a better solution, please let me know. Thanks in advance!!
Related
I have a table called feedbacks that looks like this:
id user type
1 JOhnT Positive
2 JOhnT Negative
3 Sarah Positive
4 JOhnT Positive
5 JOhnT Neutral
....................
I need to get the percentage of POSITIVE feedback for each user using PHP.
I tried something like this which i know it is wrong:
$sql = "SELECT type, count(*),
concat(round(( count(*)/(SELECT count(*) FROM feedbacks WHERE user='JOhnT' AND type='POSITIVE') * 100 ),2),'%') AS percentage
FROM feedback
WHERE user='$email' AND type='positive' GROUP BY type";
$query = mysqli_query($db_conx, $sqlJ);
echo $sql;
Could someone please advice on how to achieve this?
EDIT:
Based on the comments, this is what i have so far:
$sql = "SELECT * FROM feedbacks WHERE user='JOhnT' AND type='POSITIVE'";
$query = mysqli_query($db_conx, $sql) or die(mysqli_error($db_conx));
$productCount = mysqli_num_rows($query);
if ($productCount > 0) {
while($row = mysqli_fetch_array($query, MYSQLI_ASSOC)){
///do I need to calculate the percentage here?//
//if so, how?////
}
}
I ended up creating an array and push each $row in my whole loop into the array and then calculate the percentage like this:
$c = count($values);
$array = $values;
function array_avg($array, $round=1){
$num = count($array);
return array_map(
function($val) use ($num,$round){
return array('count'=>$val,'avg'=>round($val/$num*100, $round));
},
array_count_values($array));
}
$rating = 0;
if($c > 0){
$avgs = array_avg($array);
$rating = $avgs["positive"]["avg"];
}
This works fine for now.
You can do this a conditional average. In MySQL, you could phrase this as:
select user, avg(type = 'Positive') positive_ratio
from feedback
group by user
This gives you, for each user, a value between 0 and 1 that represents the ratio of positive types. You can multiply that by 100 if you want a percentage.
If you want this information for a single user, you can filter with a where clause (and there is no need to group by):
select user, avg(type = 'Positive') positive_ratio
from feedback
where user = 'JOhnT'
Side note: user is a MySQL keyword, hence not a good choice for a column name.
I would like get number of records in a table then divide them by 4, after dividing them by 4 i want to create sql statements with limit ranges based on my result. For example I have a table with 8 records I divide by 4, I will create 2 sql statements with a limit range like limit 0,4 and limit 4,8
Final results will look like
Select * from prop where id=123 LIMIT 0,4
Select * from prop where id=123 LIMIT 4,8
My approach was to have for loop which will count the number of sql statements to be made.
Then in the loop: first circle 0-4 and second will be 4-8
Am struggling on the limit 0-4 and limit 4-8
PHP script
include('connect.php');
$query_1 = "Select COUNT(*) as Total from prop where ref = 'SB2004'";
$results_query_1 = mysql_query($query_1);
while($row_query_1 = mysql_fetch_array($results_query_1))
{
$cnt = $row_query_1['Total'];
}
echo $cnt;
echo "<br>";
$num_grps = 0;
if ($cnt % 4 == 0 )
{
echo $num_grps = $cnt / 4 ;
}
$count_chk= $num_grps * 4;
for ($i=1;$i<=$num_grps;$i++)
{
//for loop for range
for()
{
$range = '0,4';
echo "SELECT prop_ref from prop limit".$range;
}
}
Either you've not understood the problem or haven't explained it very well.
The most immediate problem here is that you have misunderstood the syntax for the LIMIT clause. The first argument specifies the offset to start at and the second defines the number of rows to return, hence LIMIT 4,8 will return 8 rows (assuming there are 12 or more rows in the dataset).
The next issue is that you've not said if the results need to be reproducible - e.g. if you have rows with primary keys 1 and 2, should these always be returned in the same query. In the absence of an explicit ORDER BY clause, the rows will be returned based on the order in which they are found by the query.
The next issue is that you've not explained how you want to deal with the last case when the total number of rows is not an even multiple of 4.
The code you've provided counts the number of rows where ref = 'SB2004' but then creates queries which are not filtered - why?
The code you've provided does not change the limit in the queries - why?
The next issue is that there is never a good reason for running SELECT queries inside a loop like this. You didn't exlpain what you intend doing with the select queries. But based on the subsequent update....
include('connect.php');
$query_1 = "Select COUNT(*) as Total from prop where ref = 'SB2004'";
$cnt = mysql_fetch_assoc(mysql_query($query_1));
$blocks=$cnt['Total']/4 + (0 == $cnt['Total'] % 4 ? 0 : 1);
$qry2="SELECT * FROM prop where ref='SB2004' ORDER BY primary_key";
$res=mysql_fetch_assoc($qry2);
for ($x=0; $x<$blocks; $x++) {
print "<div>\n$block<br />\n";
for ($y=0; $y<4; $y++) {
print implode(",", #mysql_fetch_assoc($res)). "\n";
}
print "</div>\n";
}
It's trivial to refine this further to only issue a single query to the database.
If you really must generate individual SELECTs....
include('connect.php');
$query_1 = "Select COUNT(*) as Total from prop where ref = 'SB2004'";
$cnt = mysql_fetch_assoc(mysql_query($query_1));
$blocks=$cnt['Total']/4 + (0 == $cnt['Total'] % 4 ? 0 : 1);
for ($x=0; $x<$blocks; $x++) {
$y=$x*4;
print "SELECT * FROM prop where ref='SB2004'
ORDER BY primary_key LIMIT $y,4<br />\n"
}
sorry about the title, i really did not know what I should call it, but hopefully you will be able to aid me with my script.
What I am trying to achieve (with my less than 5 hour total experience with any sort of "programming", hence the horrid coding) is to send one query X times, and then put a new query into those newly created rows.
if(isset($_SESSION['email'])) { // IF LOGGED IN
$sql = mysql_query("SELECT max(ordrenr) FROM antalstabel") or die(mysql_error());
$maxordrenr = mysql_query($sql);
$nextnumber = $maxordrenr + 1;
$maxplusantal = $maxordrenr + $antal;
$antal = count($items); // COUNTS DIFFERENT ITEMS IN CART.
for ($i = $maxordrenr; $i <= $maxplusantal; $i++) {
$sql = mysql_query("INSERT INTO antalstabel (ordrenr) VALUES ('$nextnumber')") or die(mysql_error());
}
}
This is my first query, what this does (or what I want it to do) is to get the max ID of the table "antalstabel" add +1 and then count a certain amount up which is defined as $items untill it has executed X rows.
My first issue here, is the fact that my table consists of two key primaries, so returning a query like this would result in an error since after one return the two rows would be identical and will not execute.
The second issue is the fact that the next value in the table should not be inserted X times after each other, but rather be certain IDs added in afterwards.
What I am trying to achieve ultimately (not only by this script, but this is the current issue) is something like this:
ordrenr(key)varenr(key) antal
1 3 1
1 2 2
2 1 4
3 1 1
3 2 1
3 3 1
Does this make any sense whatsoever for anyone and can anyone tell me whether my method of doing this is jsut hopeless or have some better ideas for me to use as execution for ending up with something like this?
Should I not use primary keys or how does this work?
Thank you for even taking the time to read this :)
-Victor
EDIT for future:
changed script to this for it to work:
if(isset($_SESSION['email'])) { // IF LOGGED IN
$sql = mysql_query("SELECT * FROM antalstabel ORDER BY ordrenr DESC LIMIT 1") or die(mysql_error());
$row = mysql_fetch_assoc($sql);
$maxordrenr = $row['ordrenr'];
$nextnumber = $maxordrenr + 1;
$maxplusantal = $maxordrenr + $antal;
$antal = count($items); // COUNTS DIFFERENT ITEMS IN CART.
for ($i = $maxordrenr; $i <= $maxplusantal; $i++) {
$sql = mysql_query("INSERT INTO antalstabel (ordrenr, varenr) VALUES ('$nextnumber','1236')") or die(mysql_error());
}
$maxordrenr = mysql_query($sql);
should be
$maxordrenr = mysql_result($sql,0);
I have an issue with my code. I have 2 tables. First employee_id:
|Employee id|
1
2
3
And the second table called employee_times:
|Employee_id|Hours_dev|hours_pm|
|1|2|3|
|1|3|4|
|2|3|3|
What I am trying to do is to calculate the total time that each employee has worked (hours_dev+hours_pm). For example employee_id 1 has worked 12 hours
So far I have tried to retrieve all the employee_id from the first table and use a for loop to go through the employee_times in an SQL statement (SEE CODE BELOW). However the code does not work as it prints 0 for both employee_id and total_hours.
I am using MYSQL on a localhost server.
$sql = "SELECT employee_id FROM employee";
$result = mysql_query($sql);
while($row = mysql_fetch_array)
{
$employee_id = $row['employee_id'];
}
$employee_id_length = sizeof($employee_id);
for($i = 0; $i < $employee_id_length; $i++)
{
$sql4 = "SELECT employee_id, hours_dev, hours_pm FROM employee_times WHERE employee_id= '$employee_id[$i]'";
$result = mysql_query($sql4);
while($info = mysql_fetch_array($result));
{
$employee_id = $info['employee_id'];
$hours_dev=$info['hours_dev'];
$hours_pm=$info['hours_pm'];
$total_hours = ($total_hours + $hours_dev + $hours_pm );
}
//print "$employee_id worked for $total_hours";
}
Any help is much appreciated.
you can get sum directly
select employee_id, sum(hours_dev)+ sum(hours_pm) as total
from employee_times WHERE employee_id= '1'
group by employee_id
refer this Fiddle Demo
this should get the data you need
SELECT
hours_dev,
hours_pm,
sum(hours_dev) + sum(hours_pm) as total_hours
FROM
employee_times
WHERE
employee_id = 123
GROUP BY
employee_id
Take a look at aggregate functions:
http://www.w3schools.com/sql/sql_functions.asp
http://www.w3schools.com/sql/sql_func_sum.asp
This SQL query should pull the info much quicker than by script;
SELECT Employee_id, SUM(Hours_dev), SUM(Hours_pm), SUM(Hours_dev + Hours_pm)
FROM employee_times
GROUP BY Employee_id
I have this MySQL query :
while ($x <= 9) {
$data_1 = "SELECT scene FROM star WHERE star LIKE '%".$star."%' ORDER BY RAND() LIMIT 1";
$result_1 = mysql_query ($data_1) OR die("Error: $data_1 </br>".mysql_error());
while($row_1 = mysql_fetch_object($result_1)) {
$scene = $row_1->scene;
$x = $x + 1;
}
}
I want to get everytime a new scene for each execution, but I always get the same scene. Whats the issue? Can someone make me a few pointers in which direction I have to search ?
What you need to do is tie a random seed to each row, and tie a new one each time. Do this by assigning a random value as an aliased transient column to your table, and then select from it.
SELECT s.scene as scene FROM (
SELECT stars.scene as scene, RAND() as seed
FROM stars
WHERE star LIKE '%".$star."%'
ORDER BY seed
) s
LIMIT 1;
Using PDO it's going to look something like this:
function getScene() {
$sql = 'SELECT s.scene as scene FROM ( SELECT stars.scene as scene, RAND() as seed FROM stars WHERE star LIKE '%:star%' ORDER BY seed ) s LIMIT 1;';
$query = $this->db->prepare($sql);//'db' is the PDO connection
$query->execute(array(':star' => "Allison Brie"));
foreach ($conn->query($sql) as $row) {
print $row['scene'] . "\t";
}
}
I'm not sure what you were trying to accomplish with the rest of your code, but it mostly looks like cruft.