I know this may sound like a stupid question from a programming-newbie, but I just want to make sure I understand correctly.
After a query, what does $row[0] stand for/ result in?
Is my understanding correct that $row[0] shows ALL results?
HERE ARE EXAMPLES:
$query = "SELECT count(commentid) from comments where jokeid = $jokeid";
$result = mysql_query($query);
$row=mysql_fetch_array($result);
if ($row[0] == 0)
{
echo "No comments posted yet. \n";
} else
{
echo $row[0] . "\n";
echo " comments posted. \n";
AND THIS ONE
$query = "Select count(prodid) from products where catid = $catid";
$result = mysql_query($query);
$row = mysql_fetch_array($result);
if ($row[0] == 0)
{
echo "<h2><br>Sorry, there are no products in this category</h2>\n";
}
else
{
$totrecords = $row[0];
Thanks in advance.
$row[0] will simply echo the first column in your database.
0 is the first because all arrays in PHP (and in most programming languages) are zero-based - they simply start with zero.
$row[0] will be the value of the first column in your results. If you use mysql_fetch_assoc($result) you will have an array in the form:
array(column_name => column_value);
e.g.
$row = mysql_fetch_asssoc($result);
$value_column_1 = $row['column_1'];
You can also use mysql_fetch_object($result) to get an object with column names as the parameters.
$row = mysql_fetch_object($result);
$value = $row->column_name
mysql_fetch_array() takes the next (in your examples first) row out of the resultset and stores the data in an array $row.
$row[0] now represents the first value of that row.
So in total in your examples the variable holds the first value of the first row of your resultset.
Related
Hi I would like to compare two tables from two different databases.
Select from the first database
$sql= mysqli_query ("SELECT * FROM emasa.staff_detail");
$row = mysqli_fetch_array($sql);
Select from the second database
$sql2 = mysqli_query ("SELECT * FROM employee");
$row2 = mysqli_fetch_array($sql2);
Then I compare the two table
if ($row['icnum'] == $row2['emp_ic'])
{
echo "Data already exist in both database.";
}
else
{
while ($row = mysqli_fetch_assoc($sql))
{
echo "<td align='center' height='30'>" . $row ['name'] . "</td>";
echo "<td align='center'>" .$row['icnum'] . "</td>";
}
}
But my problem is it only compares the first row in the database.
My output should only display the staff name that is not available in the other database. However, this is my output.
Based on the output it only compares the first row. So how do I change my code so that it compares the whole row. Please help me, thank you!
You're not looping through the results of the query. You're simply getting back the first row and going with that.
Ex:
$sql= mysqli_query ("SELECT * FROM emasa.staff_detail");
This is returning a result set which you then need to use
$row = mysqli_fetch_array($sql);
to get the actual values. The problem comes when
$row = mysqli_fetch_array($sql);
by itself only gives you one row.
Solution 1
You must use code like this:
while($row = mysqli_fetch_array($sql))
{
//Do some comparison
}
Since you're going to have to loop through two different result sets, you're going to have to do a loop within a loop, build an array of results and then loop through the results afterwards to output your HTML.
Ex:
while($row = mysqli_fetch_array($sql))
{
while($row2 = mysqli_fetch_array($sql2))
{
if ($row['icnum'] == $row2['emp_ic'])
{
//add to array of equal data
}
else
{
//add to array of not equal data
}
}
}
foreach($array as $not_equal_or_equal_data)
{
//output your desired HTML
}
Solution 2
Depending on what you actually care about, you could do a sql statement like this
$sql = "
SELECT
*
FROM
emasa.staff_detail AS sd
JOIN db2.employee AS e
ON sd.icnum = e.emp_ic";
This would return all the rows where those two columns were equal
function MattsScript()
{
$query = 'SELECT * FROM `ACCOUNTING` WHERE `ACCTSTATUSTYPE` = "start" AND `Process_status` IS NULL LIMIT 0,100';
$result = mysql_query($query);
$row = mysql_fetch_assoc($result);
while ($row = mysql_fetch_assoc($result))
{
echo $row['USERNAME'] . "<br />";
echo $row['ACCTSTATUSTYPE'];
}
}
I am trying to echo the results of a query. What I think is happening here is I am saving a query to a variable, the first 100 results (LIMIT 0,100) then using a loop to echo each row to the page.
However nothing is happening, no error and nothing written to the page.
Is there something I am missing?
if you are expecting only one result remove the while loop if not leave the while loop and remove the line $row = mysql_fetch_assoc($result); before the while loop. Also make sure you are querying your database correctly.
Example: $result = mysql_query($query) or die(mysql_error());
I have a small problem and since I am very new to all this stuff, I was not successful on googling it, because I dont know the exact definitions for what I am looking for.
I have got a very simple database and I am getting all rows by this:
while($row = mysql_fetch_array($result)){
echo $row['id']. " - ". $row['name'];
echo "<br />";
}
Now, my question is: how do I filter the 2nd result? I thought something like this could work, but it doesnt:
$name2= $row['name'][2];
Is it even possible? Or do I have to write another mysql query (something like SELECT .. WHERE id = "2") to get the name value in the second row?
What I am trying to is following:
-get all data from the database (with the "while loop"), but than individually display certain results on my page. For instance echo("name in second row") and echo("id of first row") and so on.
If you would rather work with a full set of results instead of looping through them only once, you can put the whole result set to an array:
$row = array();
while( $row[] = mysql_fetch_array( $result ) );
Now you can access individual records using the first index, for example the name field of the second row is in $row[ 2 ][ 'name' ].
$result = mysql_query("SELECT * FROM ... WHERE 1=1");
while($row = mysql_fetch_array($result)){
/*This will loop arround all the Table*/
if($row['id'] == 2){
/*You can filtere here*/
}
echo $row['id']. " - ". $row['name'];
echo "<br />";
}
$counter = 0;
while($row = mysql_fetch_array($result)){
$counter++;
if($counter == 2){
echo $row['id']. " - ". $row['name'];
echo "<br />";
}
}
This While loop will automatically fetch all the records from the database.If you want to get any other field then you will only need to use for this.
Depends on what you want to do. mysql_fetch_array() fetches the current row to which the resource pointer is pointing right now. This means that you don't have $row['name'][2]; at all. On each iteration of the while loop you have all the columns from your query in the $row array, you don't get all rows from the query in the array at once. If you need just this one row, then yes - add a WHERE clause to the query, don't retrieve the other rows if you don't need them. If you need all rows, but you wanna do something special when you get the second row, then you have to add a counter that checks which row you are currently working with. I.e.:
$count = 0;
while($row = mysql_fetch_array($result)){
if(++$count == 2)
{
//do stuff
}
}
Yes, ideally you have to write another sql query to filter your results. If you had :
SELECT * FROM Employes
then you can filter it with :
SELECT * FROM Employes WHERE Name="Paul";
if you want every names that start with a P, you can achieve this with :
SELECT * FROM Employes WHERE Name LIKE "P%";
The main reason to use a sql query to filter your data is that the database manager systems like MySQL/MSSQL/Oracle/etc are highly optimized and they're way faster than a server-side condition block in PHP.
If you want to be able to use 2 consecutive results in one loop, you can store the results of the first loop, and then loop through.
$initial = true;
$storedId = '';
while($row = mysql_fetch_array($result)) {
$storedId = $row['id'];
if($initial) {
$initial = false;
continue;
}
echo $storedId . $row['name'];
}
This only works for consecutive things though.Please excuse the syntax errors, i haven't programmed in PHP for a very long time...
If you always want the second row, no matter how many rows you have in the database you should modify your query thus:
SELECT * FROM theTable LIMIT 1, 1;
See: http://dev.mysql.com/doc/refman/5.5/en/select.html
I used the code from the answer and slightly modified it. Thought I would share.
$result = mysql_query( "SELECT name FROM category;", db_connect() );
$myrow = array();
while ($myrow[] = mysql_fetch_array( $result, MYSQLI_ASSOC )) {}
$num = mysql_num_rows($result);
Example usage
echo "You're viewing " . $myrow[$view_cat]['name'] . "from a total of " . $num;
I have a query which is designed to retireve the "name" field for all records in my "tiles" table but when I use print_r on the result all I get is the first record in the database. Below is the code that I have used.
$query = mysql_query("SELECT name FROM tiles");
$tiles = mysql_fetch_array($query);
I really cant see what I have done wrong, I have also tried multiple searches within google but I cant find anything useful on the matter at hand.
<?php
// Make a MySQL Connection
$query = "SELECT * FROM example";
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)){
echo $row['name']. " - ". $row['age'];
echo "<br />";
}
?>
'mysql_fetch_array'
Returns an array that corresponds to the fetched row and moves the internal data pointer ahead.
This means that it returns array (contains values of each field) of A ROW (a record).
If you want other row, you call it again.
while ($row = mysql_fetch_array($result, MYSQL_NUM)) {
// Do something with $row
}
Hope this helps. :D
Use "mysql_fetch_assoc" instead of "mysql_fetch_array".
$query = mysql_query('SELECT * FROM example');
while($row = mysql_fetch_assoc($query)) :
echo $row['whatever'] . "<br />";
endwhile;
I believe you need to do a loop to invoke fetch array until it has retrieved all the rows.
while ($row = mysql_fetch_array($query) ) {
print_r( $row );
}
Ok I have a table with a few fields. One of the fields is username. There are many times where the username is the same, for example:
username: bob
password: bob
report: 1
username: bob
password: bob
report: 2
I did a SQL statement to select * where username='bob'; but when I do the following PHP function, it will only return the last result:
$thisrow = mysql_fetch_row($result);
I need to get every field from every row. How should I go about doing this?
$mainsection="auth"; //The name of the table
$query1="select * from auth where username='$user'";
$result = mysql_db_query($dbname, $query1) or die("Failed Query of " . $query1); //do the query
$thisrow=mysql_fetch_row($result);
echo "Study: " . $thisrow[1] . " - " . $thisrow[5];
Sorry for such a dumb question. I can't seem to get the while loops of more than one field working for the life of me.
mysql_fetch_row fetches each row one at a time. In order to retrieve multiple rows, you would use a while loop like this:
while ($row = mysql_fetch_row($result))
{
// code
}
Use a loop, and use mysql_fetch_array() instead of row:
while($row = mysql_fetch_array($result)) {
echo "Study: " . $row[1] . " - " . $row[5];
// but now with mysql_fetch_array() you can do this instead of the above
// line (substitute userID and username with actual database column names)...
echo "Study: " . $row["userID"] . " - " . $row["username"];
}
I suggest you to read this:
http://www.w3schools.com/php/php_mysql_select.asp
It will give you an overview idea of how to properly connect to mysql, gather data etc
For your question, you should use a loop:
while ($row = mysql_fetch_row($result)){//code}
As said by htw
You can also obtain a count of all rows in a table like this:
$count = mysql_fetch_array(mysql_query("SELECT COUNT(*) AS count FROM table"));
$count = $count["count"];
You can also append a normal WHERE clause to the select above and only count rows which match a certain condition (if needed). Then you can use your count for loops:
$data = mysql_query("SELECT * WHERE username='bob'");
for ($i = 0; $i
Also, mysql_fetch_array() is usually a lot easier to use as it stores data in an associative array, so you can access data with the name of the row, rather than it's numeric index.
Edit:
There's some kind of bug or something going on where my second code block isn't showing everything once it's posted. It shows fine on the preview.
I like to separate the DB logic from the display. I generally put my results into an array that I can call within the HTML code. Purely personal preference; but here's how'd I'd approach the problem: (I'd take the $sql out of the error message in production)
<?php
$sql="
SELECT *
FROM auth
WHERE username='$user';
";
$result = mysql_query($sql)
or die("Failed Query : ".mysql_error() . $sql); //do the query
while ($ROW = mysql_fetch_array($result,MYSQL_ASSOC)) {
$USERS[] = $ROW;
}
?>
HTML CODE
<? foreach ($USERS as $USER) { ?>
Study: <?=$USER['dbFieldName'];?> - <?=$USER['dbFieldName2'];?>
<? } //foreach $USER ?>
$qry=mysql_query(select * where username='bob');
if(mysql_num_rows($qry))
{
while($row=mysql_fetch_array($qry,MSQL_NUM))
{
echo $row[0]." ".$row[1]." ".$row[2]."<br>";
}
}