Get selected value from database table? - php

im new in field of manipulating databases so i have a problem.
So after making a query to select all values from a table row with something like :
while($row = $result->fetch_assoc()) { }
For example if table has names in it we would get :
John
Bob
Steve
Mark
If we put these results in a form of a link or a button, is there any way to get their value?
i tried something like :
if (isset($_POST['result_button'])) {
$value =$row['name'];
}
I tried this when i put all the results from query in to a form of button, but that only pulls the last value from table row.
I tried putting results into array like :
$result= array();
$result[]=$row['name'];
echo $result[2];
I don't fully understand how arrays works so might have done something wrong there but from what i tried this works only if i put echo$result[0];

Ok, firstly:
$row = $result->fetch_assoc()
This does not work how you're expecting it to. What this is basically saying, is that for each returned value (from the MySQL query), store in $row for this iteration of the while loop.
So, in you're example, $row will first be John, then Bob, then Steve and finally Mark. They are not all stored in the variable at the same time. Bob overwrites John, etc.
I'm going to skip your second bit of code, as it's clear you do not have an understanding of arrays.
Arrays
There is plenty of material about arrays on the web. I'm not sure why you had to post the question here, however...
To define an array:
$my_array = array();
An array with values:
$my_array = array(
"bar",
"foo"
);
Assign variables to an array:
$my_array = array();
$my_array[0] = "Help" // $my_array[0] now contains "Help"
$my_array[1] = "Me"; // $my_array[0] now contains "Me"
So, taking you're final example:
$result= array();
$result[]=$row['name'];
echo $result[2];
You haven't stored anything in the 2nd element of the array.
This would be more appropriate:
$result= array();
$result[0] = $row['name'];
echo $result[0]; // This would print what was stored in $row['name']

Related

Looping through resultings record and getting duplicates in foreach

So I am trying what I feel is a simply loop through a record result. My query returns one row of data. I am attempting to simply pull the value of each row from the returning record into a variable called $questions. However, my var $questions when printed out has duplicates in every space. It should read something like Bob|Ted|Joe|Sally and instead it is reading Bob|Bob|Ted|Ted|Joe|Joe|Sally|Sally. Why is the code below running twice in the foreach loop?
while ($row = mssql_fetch_array($result)){
foreach ($row as $col => $value) {
$questions.=$value."|";
}
}
echo "Questions: ".$questions."<br/>";
Here is all you need to do:
$questions = "";
while ($row = mssql_fetch_array($result)){
$questions .= $row['fieldName']."|";
}
echo "Questions: ".$questions."<br/>";
The foreach() in addition to the while() is unnecessary.
The mssql_fetch_array according to PHP doc:
In addition to storing the data in the numeric indices of the result
array, it also stores the data in associative indices, using the field
names as keys.
The result includes a normal array [0...n] with one element for each column, but also an associative array where each value is represented by a key named after the column name.
So if your first column is Id, you could get id from a row in two ways:
$id = $row[0];
# or you could do this
$id = $row['Id'];
This is why you get each value twice when looping through row.

PHP multidimensional array from database results

I'm a bit new to multidimensional arrays, and would like to see if I'm doing it right. preferably, I'd like to name the arrays within the main array for ease of use.
$unique_array = array(
username=>array(),
user_id=>array(),
weeknumber=>array()
);
and then I have a while loop which checks some database results:
while($row = mysql_fetch_array($query)) //yes, I know mysql is deprecated
{
$unique_array[] = username=>$row['username'], user_id=>$row['user_id'], week number=>['weeknumber'];
}
I'm not sure if I am placing the values in the array from within the while loop correctly, or if it needs to be done some other way. I couldn't find any resources I could easily understand on SO or elsewhere to deal with query results within a named array within a multidimensional array.
EDIT FOLLOW UP QUESTION: I also need to check the array for duplicate values, because there will be multiple values that are exactly the same, but I only want one of them.
Any help is appreciated!
EDIT SOLUTION:
By modifying the answer I was able to create code to fit my needs.
Array initialization:
$unique_array = array(
'username'=>array(),
'user_id'=>array(),
'weeknumber'=>array()
);
Building the array from within a while loop:
while($row = mysql_fetch_array($query))
{
$unique_array[] = array('username'=>$row['username'], 'user_id'=>$row['user_id'], 'weeknumber'=>$row['weeknumber']);
}
And finally, I need to make sure the array values are unique (there are duplicates entries as a result of database and query limitations), after the while loop I have:
print_r(multi_unique($unique_array));
Is the top level an associative array or a numeric array?
If it is an associative array, it should have structure like this:
$unique_array = array(
'username'=>array('John','Mike',...),
'user_id'=>array(1,2,3,...),
'week_number'=>array(1,2,3,...)
);
Or if it is a numeric array, it should have structure like this:
$unique_array = array(
array('username'=>'John', 'user_id'=>1, 'week_number'=>1),
array('username'=>'Mike', 'user_id'=>2, 'week_number'=>2),
array('username'=>'Sam', 'user_id'=>3, 'week_number'=>3),
...
)
for the first type use the code below:
while ($row = mysql_fetch_assoc($query)) {
$unique_array['username'][] = $row['username'],
$unique_array['user_id'][] = $row['user_id'],
$unique_array['week_number'][] = $row['week_number'],
}
for the second type, it is something like your code. But there are some syntax problems:
while($row = mysql_fetch_array($query)) //yes, I know mysql is deprecated
{
$unique_array[] = array('username'=>$row['username'], 'user_id'=>$row['user_id'], 'week_number'=>$row['weeknumber']);
}

while loop into in array

What am I trying to do is collect data from a while loop, store it into a variable. Then later in my code I see if some variable is equal to one of the values in the array and then to echo out the two other column values I got from the while loop but equal to the row that the value came from. I have tried a bunch different things and am so close but cant get it exactly.
while($row = mysql_fetch_assoc($query)){
$team[] .= "{$row['team']}";
$winslosses .= "({$row['wins']} - {$row['losses']})";
}
this returns something like
$team = (bears, badgers, wildcats)
$winslosses = ((42-24), (55-23), (32-21))
Then later in my code I want to see if its equal to a value in the array then echo $winslosses.
if(in_array(bears, $team) ) {echo '$winslosses';}
This shows all the wins and losses from each team. I want it only show me the record of the bears.
Any help would be great.
You can use array_search() to get the index of an item in an array. You can then use that index when querying $winlosses:
$team = array(bears, badgers, wildcats);
$winslosses = array("(42-24)", "(55-23)", "(32-21)");
$key=array_search(bears, $team);
echo $winslosses[$key]
results in:
(42-24)
Your best bet would be to store them in an associative array.
while($row = mysql_fetch_assoc($query)){
$winslosses[$row['team']] = "({$row['wins']} - {$row['losses']})";
}
Hope this helps
Your main problem is that you currently have $winslosses as a string, not an array, so you can't easily pull out the win/loss record for just one team.
There are several ways you could do this. The one that seems easiest to me would be to put it together as one array up front.
Something like...
while($row = mysql_fetch_assoc($query)){
$teams[$row['team']] = "({$row['wins']} - {$row['losses']})";
}
Then later on...
if(array_key_exists("bears",$teams)) {
echo $teams["bears"];
}
Or even better, store the wins/losses as a sub-array, so you have structured data that you can format however you want later on.
while($row = mysql_fetch_assoc($query)){
$teams[$row['team']] = array("wins" => $row['wins'], "losses" => $row['losses']);
}
echo $teams['bears']['wins']; // for example
Use associative array:
while($row = mysql_fetch_assoc($query)){
$team[] = {$row['team']};
$winslosses[$row['team']] = "{$row['wins']} - {$row['losses']}";
}
Then retrieve it like this:
if(in_array(bears, $team) ) {
echo $winslosses['bears'];
}
As a matter of fact, if you do not need the names of the teams in a separate array, you can just use one associative array and then retrieve it.
if (array_key_exists('bears', $winslosses)) {
echo $winslosses['bears'];
}

Trying to get field data to fit into if inarray() check

Just wondering if anyone can help me with this problem...
I want to be able to check if a certain ID (user for example is logged on) The ID's of these users will be pulled from a table, and then fed into an array and then checked if it is in there.
However when I pull the data the if inarray() no longer works as it would if I just typed it in straight within the code instead of pulling it.
I want to pull approved ID's through so they can access a certain link essentially!
Any help would be appreciated! Thanks!
<?php
mssql_select_db("$ins", $con);
$result = mssql_query("SELECT ID FROM Event WHERE EventPublic LIKE 'Yes' AND EventDate >= GETDATE() -1 ORDER BY EventDate ASC ");
while($row = mssql_fetch_array($result))
{
$test = "". $row['ID'] .",";
}
$tests = explode(',', $test);
if (in_array("2, 48", $tests)) {
echo "WOO";
}
else
{
echo "BOO";
}
mssql_close($con);
?>
in array should be an actual array
in_array(array('2', '48'), $tests)
also, it would be better to put
$tests = array();
before the while loop, then change the code inside the loop to read
$tests[] = $row['ID'];
then you can do away with the '$tests = explode(...' line.
Your having the issue with your in_array test because you are comparing an array and with a string in the following line:
if (in_array("2, 48", $tests))
The above line checks if the string "2, 48" exist in the array. But the array will have 2 as one element and 48 as a separate element. To fix this you can search for each element individually with something like:
if(in_array('2',$tests) || in_array('48',$tests))

PHP: Unexpected behavior: foreach... {$array['country'][] = $value['country']}

Why does the operator
$array['country'][] return what logically would be $array[]['country']?
What I am saying is this. If you want to extract from a MySQL array, the value of ['country'] for every row, [1],[2]...[n], you have to use
$array['country'][]
despite fact that they are ordered as
$array['row#']['country']
Is this because PHP is reading something backwards, or because I am just lacking some fundamental array information?
FULL-ish code here
$result = array();
foreach($data as $value){
$array['country'][] = $value['country'];
$array['report'][] = $value['report'];
}
$data = $array;
Let me know if I am just dumb... I can't really grasp why this is working this way.
get an id from the db
SELECT id,country,report from yourdb
while ($row = mysql_fetch_array($result)) {
$array['country'][$row['id']] = $row['country'];
$array['report'][$row['id']] = $row['report'];
}
create an id
SELECT country,report from yourdb
$i=0
while ($row = mysql_fetch_array($result)) {
$array['country'][$i] = $row['country'];
$array['report'][$i] = $row['report'];
$i++
}
Why does the operator
$array['country'][]
return what
logically would be
$array[]['country']?
It is because you are constructing the array in that way:
If you use $array['country'][] = $value['country'];, you are adding a new value to the sub-array which is part of the containing array under the country key. So it will be mapped to $array['country'][], you cannot expect otherwise.
If you want it to map to array[]['country'], then (using part of code from
#Lawrence's answer), you'd have to add the new values using explicit numerical indexes as the key:
SELECT country,report from yourdb
$i=0;
while ($row = mysql_fetch_array($result)) {
$array[$i]['country'][] = $row['country'];
$array[$i]['report'][] = $row['report'];
$i++;
}
Assuming that $data has been built by you using a loop like what you pasted in the comments (while($row=mysql_fetch_assoc($result)){$data[]=$row;}) then my answer would be because that's exactly what you asked PHP to do.
The notion $data[] = some-value-here means take that value and add it with to the end of $data array with an auto-generated key I just don't care. That is, PHP will basically see what the last item's key is, add 1 and use that as the key for the item you are adding to the array.
So what you are doing with that loop is building an array whose keys are numbers starting from 0 and incrementing (+1 each cycle, this is the [] effect) and using these keys for the rows you are getting off the database result set.
If you want to access $data in the way you described, then you have to change the way you are building it. See Lawrence Cherone's answer for that.

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