mysql_query returns nulls - php

I've got a php script which queries mysql for a certain row based on it's id.
This works fine for the first 3 rows , but on the 4th it returns nulls on all fields.
Here's the query:
mysql_query("SELECT ind,title,body,img,tags,live FROM project WHERE ind = '".$curid."' ")
let me know if you need to see more code.

I'm going to take a guess that the forth row doesn't have the id you think it does. Return them all (remove the where statement) and output them to the screen to check, or use a database browsing tool, if you have one.

Try some debugging..
$q = "SELECT ind,title,body,img,tags,live FROM project WHERE ind = '".$curid."' ";
$rs = mysql_query($q) or die("MySQL error in Query: ". $q ."<br><br>The error is:<br>".mysql_error());

when you execute query, change $curid by value that you consider is correct. verify result, if yet get null values, you can do it:
mysql_query("SELECT ind,title,body,img,tags,live FROM project WHERE ind = '".$curid."' " and
ind IS NOT NULL and title IS NOT NULL
)
for example

Related

how to show a SUM column in PHP

I have been trying to show a summaries of a column with the SUM() function in PHP.
I'm using $pointsummary= "SELECT SUM(points) FROM result WHERE id=$val"; to call my SUM function but i cant show it in my PHP. I've tried $test = mysqli_fetch_array($pointsummary); and then echo $test[0]; but it wont work.
When i do this i get:
mysqli_fetch_array() expects parameter 1 to be mysqli_result
What should i do?
Your error is caused by the fact that $pointsummary is a string and not a mysqli_result object. you need to use mysqli_query first and use what that returns. eg.
$resultObj = mysqli_query($con, $pointsummary); // <--- $con is what you got from mysqli_connect()
$resultArr = mysqli_fetch_array($resultObj);
Another note is that with SELECT SUM(points) FROM result i would suggest aliasing SUM(points) with a name you'll recognize so that instead of having to var_dump the key/values of the mysqli_fetch_array to find what the array key is for SUM(points) you'll know before hand.
to do this use AS. ie
SELECT SUM(points) AS `summary` FROM result
#Memor-X answer is good but I have a feeling that you have missed at least one step in the normal flow of event when querying a database in PHP using mysqli_
// create a query as a text string
$pointsummary = "SELECT SUM(points) as `tot_points`
FROM result
WHERE id=$val";
// issue the query to the MySQL Server for execution
// this should create a result set as long as the query is valid
$result = mysqli_query($con, $pointsummary);
// Check that the query had no errors
if ( ! $result ) {
echo mysqli_error($con);
exit;
}
// request the first row from the result set
// as we know this query will only return one row
// we dont need to do this in a loop
$row = mysqli_fetch_assoc($result);
echo $row['tot_points'];

Comparing a PHP variable to values in MySQL column

Just a little assistance, This is a pretty simple problem but it doesn't seem to work right. I am just comparing the value in a variable with all the values in a sql column. Same as if I were to compare a username input to the list of usernames in a sql column. This however is just to compare that the item id being stored in the column for that row is not an item id that is already in use.
I tested the value that I am getting back from the sql query and it is equal to the item id I typed in the input. What you will see below is the actual test to see if the id I am getting back is the one that I am looking for as well as the id of the row I can find that value in. The results I get is
2, 000002 (which is correct) that is what I am looking for.
$itemId = $_POST['itemId'];
if($sqlItemId = $dbCon->query("SELECT * FROM CVCinStoreCoins WHERE itemId = '$itemId'")){
while($data = $sqlItemId->fetch_assoc()){
printf("<p>%s, %s</p>", $data['id'], $data['itemId']);
die();
}
Then I took this out and tried to compare the value in the variable which is the same itemId already stored (000002). that is where I am going wrong.
I modified the code to look like this for further testing. Seems straight forward yet i am getting a FALSE response providing the latter echo statement "Item Id is not in use" But it is in the DB. I tried it a few different ways based on what I read in stackoverflow but none are giving me the right answer.
$sqlItemId = $dbCon->query("SELECT * FROM CVCinStoreCoins WHERE itemId = '$itemId'");
if($itemId == $sqlItemId){
echo "This item id is already in use. \n";
die();
} else {
echo "Item Id is not in use:";
die();
}
At one point I even tried a while statement to fetch the associated values prior to testing it but that didn't turn up a positive result either. Any suggestions?
Inside $sqlItemId you have the full table row (if any), not only its ID; change the SQL into a count and check the number of rows returned (if greater than 0 you have a duplicate):
$rowsCount = $dbCon->query("
SELECT COUNT(*)
FROM CVCinStoreCoins
WHERE itemId = '$itemId'
");
I don't know what $dbCon is (Doctrine DBAL? mysqli?) so I can't tell you how to use query's result.
Wy don't you just count it,
$result = $dbCon->query("SELECT COUNT(itemId) FROM CVCinStoreCoins WHERE itemId = $itemId");
if $result > 0

passing parameter to select statement from url

I have a database with a table which has two columns, lets say aa_id and bb_id - each of the the columns is a foreign key relating to another table and both columns are making a composite key for this particular table. there are several rows containing either the same aa_id and different bb_id or the same bb_id and different aa_id.
using pdo I want to extract the rows of the same - let's say - aa_id and I want to do this passing the parameter value in url. so the result of the select statement should be several rows and they should be saved as - for example - an array.
I have tried to do this with following code:
$sql = sprintf("select aa_id, bb_id from a_table where aa_id=:aa_id");
$res = $db->query($sql);
$rows = $res->fetch(PDO::FETCH_ASSOC);
foreach($rows as $key=>$value)
{
echo $key . " - " . $value . "</br>";
}
And it give no result.
I does work if I state the value of aa_id in the query like this
$sql = sprintf("select aa_id, bb_id from a_table where aa_id=191919");
, but it extracts no data if I put the value in url.
I am not really sure what to search for in the web because I don't know what's the notation called (if it is). If somebody could tell me what may be wrong with the code or give me directions to what I should look for in the web among tutorials or documentation I will be grateful. Perhaps somebody could recommend a good source of knowledge about mysql, php and pdo... Thanks in advance.
Well yeah, :indicator doesn't just automatically load in $_GET['indicator'], you need to manually bind it.
Assuming the URL ends with, ?aa_id=191919, your code might look something like this:
$sql = "select aa_id, bb_id from a_table where aa_id=:aa_id";
$res = $db->prepare($sql);
$res->bindValue(':aa_id', $_GET['aa_id'], PDO::PARAM_INT);
$res->execute();
$rows = $res->fetch(PDO::FETCH_ASSOC);
while($row=$res->fetch(PDO::FETCH_ASSOC))
{
print_r($row);
}

PHP query returns no results

I'm probably missing something obvious but when I try to execute this query, it returns no results. I plugged it directly into MySQL and also tried replacing the variable with a valid row value and I get the correct output. When I use a variable, it gives me no results. Anyone have any thoughs?
$query = "SELECT title FROM le7dm_pf_tasks WHERE project = (SELECT id FROM le7dm_pf_projects WHERE title = '".$ws_title."') ORDER BY title DESC LIMIT 1";
$result_query = mysql_query($query) or die("Error: ".mysql_error());
while ($row = mysql_fetch_assoc($result_query)) {
$result_title = $row['title'];
}
$result_title = substr($result_title,0,6);
echo $result_title;
Your SQL could do with some rework (though not the reason for your issue). No need for the nested select (which can also cause an error if it returns > 1 row). Try a join.
$sql = "
SELECT title FROM le7dm_pf_tasks t
INNER JOIN le7dm_pf_projects p ON t.project = p.id
WHERE p.title = '{$ws_title}'
ORDER BY title DESC LIMIT 1
";
You are also iterating over an unknown number of rows using the while statement. And then you exit and attempt a substring. How do you know that the last row iterated in the while had a value.
Try outputting $result_title inside the while loop itself to confirm data.
echo $result_title;
If you truly only have a single row, there is no need for the while loop. Just do
$row = mysql_fetch_assoc($result_query);
strip_tags($ws_title); - is what did it! The title was wrapped in an anchor tag that linked to that particular project page.
Thanks for all the good suggestions though. I'm gonna use some of them in the future when bug testing.

how to return array for mysql_query?

// make empty array
$sqlArray=array();
$jsonArray=array();
// START NEED FAST WORKING ALTERNATİVES -----------------------------------------------------
// first 20 vistors
$query = "SELECT user_id FROM vistors LIMIT 20";
$result = mysql_query ($query) or die ($query);
// make vistors user query array
while ($vstr_line = mysql_fetch_array($result)){
array_push($sqlArray, $vstr_line['user_id']);
}
// implode vistors user array
$sqlArray_impl = implode("', '", $sqlArray);
// END NEED FAST WORKING ALTERNATİVES -----------------------------------------------------
// Get vistors information
$query = "SELECT id, username, picture FROM users WHERE id IN ('$sqlArray_impl')";
$qry_result = mysql_query($query) or die($query);
while ($usr_line = mysql_fetch_array($qry_result)){
array_push($jsonArray, $usr_line['id'].' - '.$usr_line['username'].' - '.$usr_line['picture']);
}
print_r($sqlArray);
echo '<br><br>';
print_r($jsonArray);
see this my functions..
i need a replacement for fast working alternatives..
function within the range specified above, to me, running faster than the alternative.
the query will return back array ?
thx for all helpers !
Can you use a JOIN or SUB SELECT to reduce the query count from 2 to 1? Might not give much of a boost but worth a shot and a cleaner implementation.
Where is the bottleneck? Most likely the db and not the php code.
Are the tables/columns properly indexed? Run EXPLAIN on both queries.
Easiest would be to include first query as subquery eliminating one turn to the DB and a lot of code:
// Get vistors information
$query = "SELECT id, username, picture FROM users WHERE id IN (SELECT user_id FROM vistors LIMIT 20)";
$qry_result = mysql_query($query) or die($query);
Unless there is more reason to have the first one seperate, but that is not visible in your code example.
If you use PDO (recommended anyway...), you can return the result array all at once using fetchAll().
For your second query, you can use string concatenation in MySQL to directly return the result you want.

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