In mySQL I have a table with 8 rows, id and status.
$make=mysql_query("SELECT id, status FROM data order by id");
My question is how can I avoid using the foreach or any loop to echo the data, but instead to ave something like
<?php echo $row['status with the id 5']; ?>
and in another place of the page to echo the status with id 8 ?
You can utilize the following pattern:
$contents = [];
foreach($results as $result) {
$contents[$result->id] = $result;
}
$results contains the MySQL result set. $contents will be the associative array. It would be more comfortable if you swapped that to a function or class which works for all the tables you want to access applying this pattern. Depending on which database class you use, it might be necessary to cast the key to an integer, otherwise there will be problems accessing the index if it is passed as a string.
Note that you furthermore should migrate your code to MySQLi or PDO first.
If your table is likely to become very big, you should not implement this. Instead, it would be better if you checked in the first place which entries will be needed and load those explicitly with an IN() query.
Related
I am trying to figure out how to delete all ids in the database that do not exist in an array. I have been trying to use NOT IN in my query but I am not sure why it wont work when running it in a script the same way it works when I manually enter it into mysql. Here is an example.
mysqli_query($con, "DELETE FROM table WHERE id NOT IN ($array)");
$array is a list of ids from a json api. I use CURL to fetch the ids and I am trying to delete all ids in the database that do not match the ids in $array.
First I use another simple CURL script to scrape the apis and insert the ids found into the database and what I am trying to do here is basically make a link/data checker.
If the ids in the database are not found in the array when rechecking them then I want them deleted.
I thought that the query above would work perfect but for some reason it doesn't. When the query is ran from a script the mysql log shows the queries being ran as this.
Example:
DELETE FROM table WHERE id NOT IN ('166')
or this when I am testing multiple values.
DELETE FROM table WHERE id NOT IN ('166', '253', '3324')
And what happens is it deletes every row in the table every time. I don't really understand because if I copy/paste the same query from the log and run it manually myself it works perfect.
I have been trying various ways of capturing the array data such as array_column, array_map, array_search and various functions I have found but the end result is always the same.
For right now, just for testing I am using these 2 bits of code for testing 2 different apis which gives me the same sql query log output as above. The functions used are just a couple random ones that I found.
//$result is the result from CURL using json_decode
function implode_r($g, $p) {
return is_array($p) ?
implode($g, array_map(__FUNCTION__, array_fill(0, count($p), $g), $p)) :
$p;
}
foreach ($result['data'] as $info){
$ids = implode_r(',', $info['id']);
mysqli_query($con, "DELETE FROM table WHERE id NOT IN ($ids)");
}
And
$arrayLength = count($result);
for($i = 0; $i < $arrayLength; $i++) {
mysqli_query($con, "DELETE FROM table WHERE id NOT IN ('".$result[$i]['id']."')");
}
If anyone knows what is going on i'd appretiate the help or any suggestions on how to achieve the same result. I am using php 7 and mysql 5.7 with innodb tables if that helps.
It probably doesn't work because your IN value is something like this
IN('1,2,3,4');
When what you want is this
IN('1','2','3','4')
OR
IN( 1,2,3,4)
To get this with implode include the quotes like this
$in = "'".implode("','", $array)."'";
NOTE whenever directly inputting variables into SQL there is security Implications to consider such as SQLInjection. if the ID's are from a canned source you're probably ok, but I like to sanitize them anyway.
You can't mix array and string.
This works:
mysqli_query($con, "DELETE FROM table WHERE id NOT IN (".implode(',', $ids).")");
I have an external database that I am trying to access from within a Drupal page, I have successfully queried the database and output data to the page using fetchAssoc(), however this only returns the first row in the database. I would like to return all rows into an array for processing, so I'm attempting to use fetchAllAssoc(), this however results in an exception. The database has the following SQL fields:
id, model, manufacturer, url, date_modified
My test code is as follows:
<?php
db_set_active('product_db');
$query = db_select('product', 'p')->fields('p');
$sqlresults = $query->execute()->fetchAllAssoc('id');
foreach($sqlresults as $sqlresult)
{
printf($sqlresult);
}
db_set_active();
?>
I'm thinking that it is the key field 'id' that I am specifying with fetchAllAssoc() that is the problem, as fetchAssoc() prints values correctly. All documentation I have found seems to say that you pass a database field as the key but I have also passed a numeric value with no success.
Many thanks in advance for any advice, I'm sure I'm just missing something stupid.
I think it should work in this way, but within the foreach you want to print the $sqlresult variable as a string, but it is an object (it causes the error).
printf function needs a string as the first parameter, see:
http://php.net/manual/en/function.printf.php
Use for instance var_dump instead:
var_dump($sqlresult);
Is there any way to print the resource_id without mysql_fetch_array.I dont want to loop through result.I want print only the first row at top.I know mysql has been depreciated.This is for old project.
You can make use of arrays in your case
$all_rows = array();
.
. // your query
.
while($dbrow = mysql_fetch_array($query))
{
$all_rows[] = $dbrow;
}
$first_row_array = $all_rows[0]; // first row will be stored here
/*
uncomment the below line if you do not want to use the
first row again while looping through the remaining
rows
*/
/* unset($all_rows[0]); */
foreach($first_row_array as $first_row)
{
// do something with first row data
}
foreach($all_rows as $dbrow)
{
// loop through all the rows returned including the first row
}
A resource in itself is a pretty meaningless type. It only means something to specific functions, like mysql_*. When querying the database, there are certain resources allocated on the MySQL server which hold your requested result; PHP doesn't really have access to those results yet. To give you a handle on those resources on the MySQL server, you get a resource type variable. It's basically just your ticket, saying "if you ever want to access that data waiting for you on the MySQL server, use this number."
So, if you want to output the data from the MySQL server, you will have to fetch it from there, e.g. with mysql_fetch_assoc. That then returns the data to you which you can print.
If you just want the first result, just call that function once.
I'm brand new to the PDO syntax and I'm liking the learning curve! I'm refactoring code - migrating over from archaic mysqli_* methods.
Predictably, I've run into some snags, being a novice. One of the big ones is (forgive if this is a dumb question) retrieving data from the DB and echoing it out on the page. Here is what I have so far:
$getURLid = $_GET['id'];
$idQuery = $connection->prepare("SELECT * FROM pages WHERE page_id = :getURLid");
$idQuery->execute(array(':getURLid' => $getURLid));
$idRetrieved = $idQuery->fetchAll(); // This is the part I'm unclear on.
When I echo $idRetrieved['value'] to the page, nothing shows up. I'm missing something or misunderstanding how it works. Maybe fetchAll isn't what I should be using.
If it is, is a loop necessary to retrieve all rows? I was under the impression that fetchAll would loop through them automatically based on what I've read.
Thanks for the help.
Read the doco for PDOStatement::fetchAll closely. It returns an array of row data.
The type of data representing each row depends on your fetch mode which by default is PDO::FETCH_BOTH. This would mean each row is an array with both numeric and associative keys. If you're only going to access the data associatively, I'd recommend using PDO::FETCH_ASSOC, eg
$idRetrieved = $idQuery->fetchAll(PDO::FETCH_ASSOC);
You would then either need to loop or access each row via its index, eg
foreach ($idRetrieved as $row) {
echo $row['value'];
}
// or
echo $idRetrieved[0]['value']; // assuming there's at least one row.
I've read through PHP PDO Book and now have some basic questions:
If i understood correctly, i'll have to use begin_transaction() in order to turn off autocommit. If i am okay with autocommit, i am always good to go with a simple query()Is this correct?
Did i get it right, that there is basically no difference between query() and exec(), except of the above asked topic?
I made a query like this one:
foreach ($db->query('SELECT * from user') as $row) {
$row = json_encode($row);
echo $row;
}
Which returns a JSON Object:
{
"alias":"tk",
"0":"tk",
"password":"pw",
"1":"pw",
}
This is basically correct, however, why is each value returned twice, once with my chosen keyword and another time with an Integer key?
why is each value returned twice, once with my chosen keyword and another time with an Integer key?
The array has the values both with the column names as keys, and the column ordinals too. So you could access the values from the result set by using the number of which column you want. (of course, that does not seem to be of too much use with a select * statement...)
You can affect this behaviour with PDOStatement::setFetchMode(). The constants starting with PDO::FETCH_ are applicable here. Their documentation can be found here