PHP and encapsulating MySQL rows into a JSON array - php

I'm playing with a guestbook/chatroom idea and have a MySQL table setup with three columns:
1 - id - Primary Key auto increment
2 - name - String
3 - comment - string
I have very little experience with PHP but this is what I've put together for this operation:
$result = mysql_query("SELECT * FROM guestbook");
$i = 0;
while($row = mysql_fetch_array($result))
{
//add the row to the $chat array at specific index of $i
$chat[$i] = $row;
$i += 1;
}
$encode = json_encode($chat);
echo "$encode";
However, output from this looks pretty awful:
[{"0":"1","id":"1","1":"Justin ","name":"Justin ","2":"Comment 1","comment":"Comment 1"},
{"0":"2","id":"2","1":"Justin ","name":"Justin ","2":"Another comment","comment":"Another comment"},
{"0":"3","id":"3","1":"Justin ","name":"Justin ","2":"Look at this comment!","comment":"Look at this comment!"},
{"0":"4","id":"4","1":"Justin ","name":"Justin ","2":"Ok I'm done talking","comment":"Ok I'm done talking"}]
I was hoping to get three fields: id, name, and comment, but it looks like things doubled. Can anyone help?
Thanks!

To paraphrase Marc, Just replace this line:
while($row = mysql_fetch_array($result))
With this:
while($row = mysql_fetch_array($result, MYSQL_ASSOC))
To get cleaner JSON. By default mysql_fetch_array() will return both an integer index and an associative index, you only want the associative index.

mysql_fetch_array returns a compound array: indexed AND keyed. To fetch just one or the other, use mysql_fetch_row() (indexed only), mysql_fetch_assoc() (keyed only), or use the extra argument on fetch_array to specify which you want: mysql_fetch_array($result, MYSQL_BOTH);

Related

Separating mysql fetch array results

i have a mysql table the contains an index id, a data entry and 10 other columns called peso1, peso2, peso3...peso10. im trying to get the last 7 peso1 values for a specific id.
like:
$sql = mysql_query("SELECT * FROM table WHERE id='$id_a' ORDER BY data DESC LIMIT 0, 7");
when i try to fetch those values with mysql_fetch_array, i get all values together.
example:
while($line = mysql_fetch_array($sql)) {
echo $line['peso1'];
}
i get all peso1 values from all 7 days together. How can i get it separated?
They will appear all together because you are not separating them as you loop through them.
for example, insert a line break and you will see them on separate lines
while($line = mysql_fetch_array($sql)) {
echo $line['peso1'] ."<br />";
}
You could key it as an array like so
$myArray = array();
$i = 1;
while($line = mysql_fetch_array($sql)) {
$myArray['day'.$i] = $line['peso1'];
$i++;
}
Example use
$myArray['day1'] // returns day one value
$myArray['day2'] // returns day two value
It's not clear what you mean by "separated" so I'm going to assume you want the values as an array. Simply push each row field that you want within your while loop onto an array like this:
$arr = array();
while($line = mysql_fetch_array($sql)) {
$arr[]=$line['peso1'];
}
print_r($arr);//will show your peso1 values as individual array elements

mysql_fetch_array fetch date fetch each element twice

i hope to iterate the elements fetched from datebase
But the result looks very unexpected .
I found the code below print the $value and echo "<td id=".$key.$tag.">".$value."</td>";twice. Is there anything i misunderstood?
function selectTable($table){
$sql= "SELECT * FROM ".$table ;
$result=mysql_query($sql)
or die(mysql_error());
return $result;
}
$table = 'battery_con';
$result = selectTable($table);
unset($table);
while($row = mysql_fetch_array($result)){
......
foreach ($row as $key => $value) {
print $value;
echo "<td id=".$key.$tag.">".$value."</td>";
}
.....
}
You are using mysql_fetch_array which by default returns an array with two elements per column (this is what the second (optional) paramter means: result_type = MYSQL_BOTH).
One is indexed with an integer representing the column index, one is indexed with the column name.
That's why you get two entries in your list. You would set the second parameter to MYSQL_ASSOC to get just one value per column.
Please use mysql_fetch_assoc() place of mysql_fetch_array()
I hope it will help
In addition to #Andreas's answer by default mysql_fetch_array gives both associative and numeric indexes, if you don't want this you can limit it with the second parameter in your while loop:
$row = mysql_fetch_array($result, MYSQL_NUM); // numeric keys only
$row = mysql_fetch_array($result, MYSQL_ASSOC); // associative keys only
As previously mentioned by #sonusindhu you can also use mysql_fetch_row to only get numeric keys, or mysql_fetch_assoc to only get associative keys.
Update
The mysql_xxx() functions being deprecated you should consider using the mysqli_xxx() functions instead.
See the example 1 of the php manual for more details:
http://php.net/manual/en/mysqli-result.fetch-array.php

making three dimensional array that has an unknown amount of arrays inside

I'm trying to store data from a table, and I do not know how many lines will be in said table. My idea was to make a main array called data, a sub array for each line with just numeric labels (1,2,3,etc) and then inside each of those would be the actual data from each line, so it would be like this:
data
->1
->item1
->item2
->item3
->2
->item1
->item2
->item3
->3
->item1
->item2
->item3
ETC. I know how to work with multidimensional arrays and I know there are easy ways to accomplish this in java, but I can't for the life of me figure out how to do it in php.
To keep on adding to an array simply use the following code:
$myArray[] = 'another value';
Notice the [] this tells php to add another value to the array (without removing previous elements)
See here for a quick tutorial on mutidimensional arrays:
http://webcheatsheet.com/PHP/multidimensional_arrays.php
And this:
http://www.developerdrive.com/2012/01/php-arrays-array-functions-and-multidimensional-arrays/
Try,
foreach($rows as $v) {
$data[] = array($v['item1'], $v['item2'], $v['item3']);
}
To map mySQL data to a multidimensional array:
$query = mysql_query("SELECT * FROM table WHERE uid = '1' ORDER BY id DESC");
$results = array();
$i = 0;
while($line = mysqli_fetch_array($query, MYSQL_ASSOC)){
$results[$i] = $line;
$i++;
}

How to select multiple rows from mysql with one query and use them in php

I currently have a database like the picture below.
Where there is a query that selects the rows with number1 equaling 1. When using
mysql_fetch_assoc()
in php I am only given the first is there any way to get the second? Like through a dimesional array like
array['number2'][2]
or something similar
Use repeated calls to mysql_fetch_assoc. It's documented right in the PHP manual.
http://php.net/manual/function.mysql-fetch-assoc.php
// While a row of data exists, put that row in $row as an associative array
// Note: If you're expecting just one row, no need to use a loop
// Note: If you put extract($row); inside the following loop, you'll
// then create $userid, $fullname, and $userstatus
while ($row = mysql_fetch_assoc($result)) {
echo $row["userid"];
echo $row["fullname"];
echo $row["userstatus"];
}
If you need to, you can use this to build up a multidimensional array for consumption in other parts of your script.
$Query="select SubCode,SubLongName from subjects where sem=1";
$Subject=mysqli_query($con,$Query);
$i=-1;
while($row = mysqli_fetch_array($Subject))
{
$i++;
$SubjectCode[$i]['SubCode']=$row['SubCode'];
$SubjectCode[$i]['SubLongName']=$row['SubLongName'];
}
Here the while loop will fetch each row.All the columns of the row will be stored in $row variable(array),but when the next iteration happens it will be lost.So we copy the contents of array $row into a multidimensional array called $SubjectCode.contents of each row will be stored in first index of that array.This can be later reused in our script.
(I 'am new to PHP,so if anybody came across this who knows a better way please mention it along with a comment with my name so that I can learn new.)
This is another easy way
$sql_shakil ="SELECT app_id, doctor_id FROM patients WHERE doctor_id = 201 ORDER BY ABS(app_id) ASC";
if ($result = $con->query($sql_shakil)) {
while ($row = $result->fetch_assoc()) {
printf ("%s (%s)\n", $row["app_id"], $row["doctor_id"]);
}
Demo Link
It looks like the complete solution has not been suggested yet
$Query="select SubCode,SubLongName from subjects where sem=1";
$Subject=mysqli_query($con,$Query);
$Rows = array ();
while($row = mysqli_fetch_array($Subject))
{
$Rows [] = $row;
}
The $Rows [] = $row appends the row to the array. The result is a multidimensional array of all rows.

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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