I'm trying to get data from a table column that has a corresponding ID, but when I try to get an ID it gives me a 'resource ID'. My column ID holds INTs, and I found that if I add or subtract to the resource ID i get a number so I tried adding then subtracting 1, but it still isn't working.
<?php
mysql_connect("localhost","root","") or die(mysql_error());
mysql_select_db("blog") or die(mysql_error());
$strSQL = "SELECT id FROM blogtable ORDER BY id DESC";
$rs = mysql_query($strSQL);
$artID = $rs-1+1;//So if I don't do this, I get resource ID#'#'
?>
This code is on the same page, but in a separate container.
<?php
$getArticle = "SELECT title FROM blogtable Where id = '$artID'";
$selectedArticle = mysql_query($getArticle);
echo $selectedArticle;
?>
I was hoping this would get me the text from my title column, but it just gives me another resource id.
You can use
$result = mysql_fetch_object($rs);
$artID = $result->id;
...
$selectedArticle = mysql_query($getArticle);
$res = mysql_fetch_object($selectedArticle);
echo $res->title;
But i will recommende using PDO or mysqli functions since mysql_ functions will become obsolete.
mysqli examples: http://www.w3schools.com/php/php_ref_mysqli.asp
or
PDO tutorials: http://wiki.hashphp.org/PDO_Tutorial_for_MySQL_Developers
mysql_query gives you resource id. If you want to get your ID;
$id = 0;
while ($row = mysql_fetch_assoc($rs)) {
$id = $row['ID'];
}
Or
$row = mysql_fetch_array($rs);
and get id from $row array
//get the current member count
$sql = ("SELECT count(member_id) as total_members from exp_members");
$result = mysql_query($sql) or die(mysql_error());
$num_rows = mysql_num_rows($result);
if ($num_rows != 0) {
while($row = mysql_fetch_array($result)) {
$total_members = $row['total_members'];
}
}
//get list of products
$sql = ("SELECT m_field_id, m_field_label from exp_member_fields where m_field_name like 'cf_member_ap_%' order by m_field_id asc");
$result = mysql_query($sql) or die(mysql_error());
$num_rows = mysql_num_rows($result);
if ($num_rows != 0) {
while($row = mysql_fetch_array($result)) {
$m_field_id = $row['m_field_id'];
$m_field_label = $row['m_field_label'];
$sql2 = ("SELECT count(m_field_id_".$m_field_id.") as count from exp_member_data where m_field_id_".$m_field_id." = 'y'");
$result2 = mysql_query($sql2) or die(mysql_error());
$num_rows2 = mysql_num_rows($result2);
if ($num_rows2 != 0) {
while($row2 = mysql_fetch_array($result2)) {
$p = ($row2['count']/$total_members)*100;
$n = $row2['count'];
$out .= '<tr><td>'.$m_field_label.'</td><td>'.number_format($p,1).'%</td><td>'.$n.'</td></tr>';
}
}
}
}
It's easier to help if you can describe in non-code terms what you're trying to accomplish. But one indicator of a problem is seeing a php loop on rows from one query with another query executing for each row.
There are ways to query for subtotals. But it would be easier to explain if you can explain the goal a bit.
count query would always return 1 row, so you don't need the loop
$sql = ("SELECT count(member_id) as total_members from exp_members");
$result = mysql_query($sql) or die(mysql_error());
$row = mysql_fetch_array($result);
$total_members = $row['total_members'];
Other than that i am not sure how you can make it better. You can do the same for both of your count queries.
As these are straight forward queries, any bottleneck i guess now would be on the MySQL end
The first COUNT query ("get the current member count") should execute almost instantaneously.
The second query ("get list of products") may be slow depending on your indexes. You are querying on m_field_name and then ordering on m_field_id so you may need a combined index of the two.
The third query, which is executed repeatedly (once for each product), is querying on m_field_id_* (i.e. any of a number of possible fields), so you should probably make sure they are indexed.
In summary, you need to a) figure out which query is running slow, b) index things that need to be indexed, and c) combine queries if possible.
I'm using sqlsrv driver, and I'm trying to make a query like this:
$query = "select * from products";
$result = sqlsrv_query($conn,$query);
echo $result;
This returns me nothing. What is wrong with the query or PHP code?
This is how it would be done with a mysql connection. I haven't used sqlsrv driver, so it may not work as is but you get an idea.
Bruno posted a link with sqlsrv driver detailed code.
The real issue is that you can't just echo $result. It's an array and you have to do it row by row or write a function that echoes the complete $result. That way you can also filter rows or columns and format every field as you like.
$query = "select id, title, price from products";
$result = mysql_query($conn,$query);
$num=mysql_numrows($result);
$i=0;
while ($i < $num)
{
$id=mysql_result($result,$i,"id");
$title=mysql_result($result,$i,"title");
$price=mysql_result($result,$i,"price");
echo "<b>id: $id</b> Product: $title , Price: $price<br>";
$i++;
}
I agree with that the real problem is that you can't echo a result - you have to iterate through the results. Just so you have an example with the sqlsrv extension, here's how I'd do it:
$query = "select id, title, price from products";
$result = sqlsrv_query($conn, $query);
while($row = sqlsrv_fetch_array($result, SQLSRV_FETCH_ASSOC))
{
echo "<b>id: $row['id']</b> Product: $row['product'], Price: $row['price'];
}
-Brian
Hi please tell me if this is a low resources piece of code, and if it is not how shall I change it ? Thank you!
$query = 'SELECT MAX(ID) as maxidpost
FROM wp_posts';
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)) {
$postid = $row['maxidpost']+1;
echo "p=$postid";
The improvement is debatable, but:
$query = 'SELECT MAX(ID) +1 as maxidpost
FROM wp_posts';
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)) {
echo "p = ". $row["maxidpost"];
You can do math in SQL statements, saving you from having to do the operation in PHP.
It'd be nice to know what you're using this for - if it's the next id to be inserted, using AUTO_INCREMENT would be safer. SELECT statements are generally given higher priority over INSERT/UPDATE/DELETE, and thus can read before an insert from another source -- which would risk duplicates.
Because you are returning one row, you should do something like:
$query = 'SELECT MAX(ID) as maxidpost FROM wp_posts';
$result = mysql_query($query) or die(mysql_error());
$row = mysql_fetch_row($result);
$postid = $row['maxidpost']+1;
echo "p=$postid";
Otherwise seems about as good as you could do.
You can recalculate the post code after each post. Start with zero. Select it from the database, use that id, add one, save back to database.
Or you could use auto increment (if that is possible).
What's the best way with PHP to read a single record from a MySQL database? E.g.:
SELECT id FROM games
I was trying to find an answer in the old questions, but had no luck.
This post is marked obsolete because the content is out of date. It is not currently accepting new interactions.
$id = mysql_result(mysql_query("SELECT id FROM games LIMIT 1"),0);
$link = mysql_connect('localhost','root','yourPassword')
mysql_select_db('database_name', $link);
$sql = 'SELECT id FROM games LIMIT 1';
$result = mysql_query($sql, $link) or die(mysql_error());
$row = mysql_fetch_assoc($result);
print_r($row);
There were few things missing in ChrisAD answer. After connecting to mysql it's crucial to select database and also die() statement allows you to see errors if they occur.
Be carefull it works only if you have 1 record in the database, because otherwise you need to add WHERE id=xx or something similar to get only one row and not more. Also you can access your id like $row['id']
Using PDO you could do something like this:
$db = new PDO('mysql:host=hostname;dbname=dbname', 'username', 'password');
$stmt = $db->query('select id from games where ...');
$id = $stmt->fetchColumn(0);
if ($id !== false) {
echo $id;
}
You obviously should also check whether PDO::query() executes the query OK (either by checking the result or telling PDO to throw exceptions instead)
Assuming you are using an auto-incrementing primary key, which is the normal way to do things, then you can access the key value of the last row you put into the database with:
$userID = mysqli_insert_id($link);
otherwise, you'll have to know more specifics about the row you are trying to find, such as email address. Without knowing your table structure, we can't be more specific.
Either way, to limit your SELECT query, use a WHERE statement like this:
(Generic Example)
$getID = mysqli_fetch_assoc(mysqli_query($link, "SELECT userID FROM users WHERE something = 'unique'"));
$userID = $getID['userID'];
(Specific example)
Or a more specific example:
$getID = mysqli_fetch_assoc(mysqli_query($link, "SELECT userID FROM users WHERE userID = 1"));
$userID = $getID['userID'];
Warning! Your SQL isn't a good idea, because it will select all rows (no WHERE clause assumes "WHERE 1"!) and clog your application if you have a large number of rows. (What's the point of selecting 1,000 rows when 1 will do?) So instead, when selecting only one row, make sure you specify the LIMIT clause:
$sql = "SELECT id FROM games LIMIT 1"; // Select ONLY one, instead of all
$result = $db->query($sql);
$row = $result->fetch_assoc();
echo 'Game ID: '.$row['id'];
This difference requires MySQL to select only the first matching record, so ordering the table is important or you ought to use a WHERE clause. However, it's a whole lot less memory and time to find that one record, than to get every record and output row number one.
One more answer for object oriented style. Found this solution for me:
$id = $dbh->query("SELECT id FROM mytable WHERE mycolumn = 'foo'")->fetch_object()->id;
gives back just one id. Verify that your design ensures you got the right one.
First you connect to your database. Then you build the query string. Then you launch the query and store the result, and finally you fetch what rows you want from the result by using one of the fetch methods.
$link = mysql_connect('localhost','root','yourPassword')
mysql_select_db('database',$link);
$sql = 'SELECT id FROM games'
$result = mysql_query($sql,$link);
$singleRow = mysql_fetch_array($result)
echo $singleRow;
Edit: So sorry, forgot the database connection. Added it now
'Best way' aside some usual ways of retrieving a single record from the database with PHP go like that:
with mysqli
$sql = "SELECT id, name, producer FROM games WHERE user_id = 1";
$result = $db->query($sql);
$row = $result->fetch_row();
with Zend Framework
//Inside the table class
$select = $this->select()->where('user_id = ?', 1);
$row = $this->fetchRow($select);
The easiest way is to use mysql_result.
I copied some of the code below from other answers to save time.
$link = mysql_connect('localhost','root','yourPassword')
mysql_select_db('database',$link);
$sql = 'SELECT id FROM games'
$result = mysql_query($sql,$link);
$num_rows = mysql_num_rows($result);
// i is the row number and will be 0 through $num_rows-1
for ($i = 0; $i < $num_rows; $i++) {
$value = mysql_result($result, i, 'id');
echo 'Row ', i, ': ', $value, "\n";
}
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$db = new mysqli('localhost', 'tmp', 'tmp', 'your_db');
$db->set_charset('utf8mb4');
if($row = $db->query("SELECT id FROM games LIMIT 1")->fetch_row()) { //NULL or array
$id = $row[0];
}
I agree that mysql_result is the easy way to retrieve contents of one cell from a MySQL result set. Tiny code:
$r = mysql_query('SELECT id FROM table') or die(mysql_error());
if (mysql_num_rows($r) > 0) {
echo mysql_result($r); // will output first ID
echo mysql_result($r, 1); // will ouput second ID
}
Easy way to Fetch Single Record from MySQL Database by using PHP List
The SQL Query is SELECT user_name from user_table WHERE user_id = 6
The PHP Code for the above Query is
$sql_select = "";
$sql_select .= "SELECT ";
$sql_select .= " user_name ";
$sql_select .= "FROM user_table ";
$sql_select .= "WHERE user_id = 6" ;
$rs_id = mysql_query($sql_select, $link) or die(mysql_error());
list($userName) = mysql_fetch_row($rs_id);
Note: The List Concept should be applicable for Single Row Fetching not for Multiple Rows
Better if SQL will be optimized with addion of LIMIT 1 in the end:
$query = "select id from games LIMIT 1";
SO ANSWER IS (works on php 5.6.3):
If you want to get first item of first row(even if it is not ID column):
queryExec($query) -> fetch_array()[0];
If you want to get first row(single item from DB)
queryExec($query) -> fetch_assoc();
If you want to some exact column from first row
queryExec($query) -> fetch_assoc()['columnName'];
or need to fix query and use first written way :)