I want to get the maximum id of row data. In my table first column is id then firstname and etc.
this is the sql command I used to get the max(id) of row data.
<?PHP $maxid=$this->db->query("SELECT MAX(id) FROM `emplyee_personal_details`");
print_r( $maxid) ;?>
but it prints bunch of data as it is a array. But I need only the maximam id of row data for validation before data inserting and updating.
How to get the maxid. I use codeigniter framework.
Try this:
$maxid = $this->db->query('SELECT MAX(id) AS `maxid` FROM `emplyee_personal_details`')->row()->maxid;
UPDATE
This will work even if your table is empty (unlike my example above):
$maxid = 0;
$row = $this->db->query('SELECT MAX(id) AS `maxid` FROM `emplyee_personal_details`')->row();
if ($row) {
$maxid = $row->maxid;
}
The problem with using a raw query like "SELECT MAX(id) ..." is it is not abstract and may not work for every SQL engine. I think the active record way to do it is like this:
$this->db->select_max('id');
$query = $this->db->get('emplyee_personal_details');
// Produces: SELECT MAX(id) as age FROM emplyee_personal_details
See: http://ellislab.com/codeigniter/user-guide/database/active_record.html
SELECT id FROM table ORDER BY id DESC LIMIT 1
That will get you the highest id value, and when I read this, "it prints bunch of data as it is a array" I get the sense that what you really want is a part of that array. DB queries always return complex structures like arrays or objects. So if you wanted just the scalar value (the number as an integer) you might use something like this:
$maxid = (int)$maxid['id'];
or like this (if you have an object):
$maxid = (int)$maxid->id;
HTH, ~Ray
Try this,hope it helps,
return $this->db->select_max('id')
->get('your_table_name')
->row()->id;
public function getMaxCategoryId() {
$query = $this->db->query("SELECT category_id+1 AS maxid FROM " . DB_PREFIX . "category ORDER BY category_id DESC LIMIT 1");
return $query->row['maxid'];
}
error undefined index maxid
<?php`$qry = "select max(ID)+1 As ID from records";`
$result = $con->query($qry);
$row = $result->fetch_assoc();`echo "New ID To Enter = ".$row["ID"];?>
After Connection Just Write This Code It Will Work
Related
In my mySQL database, I insert an entry into the db, and then I need to get the number of that last insertion. I have it set to auto-increment. Using the query "SELECT MAX(ID) FROM TABLE;" works fine in the database, I just need to capture that number to a variable in PHP.
$rowSQL = mysqli_query($con, "SELECT MAX(ID) FROM TABLE");
$row = mysqli_fetch_assoc($rowSQL);
$largestUID = $row['max'];
echo $largestUID;
Thanks for the help!
Use the AS modifier in your query. This modifier gives your selected items an alias.
$rowSQL = mysqli_query($con, "SELECT MAX(ID) AS maxid FROM TABLE");
$row = mysqli_fetch_assoc($rowSQL);
$largestUID = $row['maxid'];
echo $largestUID;
Use an alias name for the calculated column
SELECT MAX(ID) as max_id FROM TABLE
$largestUID = $row['max_id'];
I created a PHP file to populate a page, using AJAX, but I can't find a solution to my problem.
Here's my PHP and its Outputs:
$result = mysql_query("SELECT id, product, picture FROM table1 ORDER BY id DESC");
$products = array();
while($product = mysql_fetch_array($result, MYSQL_ASSOC)) {
$products[] = ($product);
}
$json = json_encode($products);
$output = isset($_GET['callback']) ? "{$_GET['callback']}($json)" : $json;
echo $output;
This will print:
[{"id":"5","product":"product5","picture":"picture5.jpg"},
{"id":"4","product":"product4","picture":"picture4.jpg"},
{"id":"3","product":"product3","picture":"picture3.jpg"},
{"id":"2","product":"product2","picture":"picture2.jpg"},
{"id":"1","product":"product1","picture":"picture1.jpg"}]
I want to add the field "In_Stock" on this Output using a another query to output something like this:
[{"id":"5","product":"product5","picture":"picture5.jpg","in_stock":"yes"},
{"id":"4","product":"product4","picture":"picture4.jpg","in_stock":"no"},
{"id":"3","product":"product3","picture":"picture3.jpg","in_stock":"yes"},
{"id":"2","product":"product2","picture":"picture2.jpg","in_stock":"yes"},
{"id":"1","product":"product1","picture":"picture1.jpg","in_stock":"no"}]
My question is: Its possible to use the value of the array (Inside the first While) to do a search in another table, add this value to products array and keep the same "layout" on the output above?
EDIT:
These are my tables:
TABLE1
id
product
picture
And the second one
TABLE2
id
user
product_id
in_stock
The same product may have different stocks depending on the User...
Yes, you could do another query, but it probably makes more sense to just alter the first query to include all the data you need, which would look something like this:
mysql_query("SELECT table1.id, table1.product, table1.picture, table2.in_stock
FROM table1
LEFT JOIN table2 ON (table1.id = table2.product_id
AND table2.user = " . intval($_SESSION['user']) . ")
ORDER BY table1.id DESC");
Edit: Added in the user from session per your comment. I used intval because I am assuming you are using an integer for the id of the user, and I don't know how the $_SESSION value got set - if it is from user input then it should be escaped.
As a side note, mysql_query is deprecated, you should look into mysqli and prepared statements.
How would I add up all the integers in the column, _view_count_, on my table, 'videos', then echo it to display on my page?
For example:
if row id 1 has view_count == 328
and
if row id 2 has view_count == 271
How would I make MySQL add those together and echo it out?
You can use MySQL's SUM() and your SQL query would look something similar to:
SELECT SUM(view_count) FROM videos;
To query and echo the value, if you're using mysqli methods in your PHP code, you can use:
$result = $mysqli->query('SELECT SUM(view_count) AS sum FROM videos;');
$row = $result->fetch_assoc($result);
echo $row['sum'];
Assuming you have a $mysqli object defined your code should look like:
$query = "SELECT Sum(view_count) as mySum FROM videos";
$result = $mysqli->query($query);
$row = $result->fetch_assoc($result);
echo $row['mySum'];
SELECT SUM(view_count) FROM videos
Assuming you have a COLUMN id, you can use SUM together with IN, like so:
SELECT SUM(view_count) FROM videos WHERE id in (1,2)
I have small PHP script which has
$query = "SELECT MAX(id) FROM `dbs`";
//query run
$row = mysql_fetch_array($result);
$val = $row[0];
Which runs fine, but I want to understand why i can't access the row with the fieldname, like if i have this
$query = "SELECT id FROM `dbs`";
i am able to use the folowing
$val = $row['id'];
but whenever i use this MAX() function, i have to change to
$val = $row[0];
to access the values
I have no clue about this. Any help would be appreciated. Thankss
You need to give it an alias:
<?php
$query = "SELECT MAX(id) AS `id` FROM `dbs`";
//query run
$row = mysql_fetch_array($result);
$val = $row['id'];
Edit:
To explain this it's probably best to show an example of a different query:
SELECT MAX(`id`) AS `maxId`, `id` FROM `dbs`
Using the above it will return as many rows are in the table, with 2 columns - id and maxId (although maxId will be the same in each row due to the nature of the function).
Without giving it an alias MYSQL doesn't know what to call it, so it won't have an associative name given to it when you return the results.
Hope that helps to explain it.
SELECT MAX(id) AS myFieldNameForMaxValue
FROM `dbs`
and then
$row = mysql_fetch_array($result);
$val = $row['myFieldNameForMaxValue'];
If you run this query on mysql commandline you'll see that the field name returned by mysql is MAX(id). Try running on phpmyadmin and you'll see the same. So if you try $row['MAX(id)'] it'll work. When using a mysql function, it gets added to the name, so use an alias, like other said here, and you're good to go: SELECT MAX(id) AS id FROM dbs. Also, never forget to use the ` chars, just in case you have some columns/tables with reserved names, likefrom`.
I want to fetch the last result in MySQL database table using PHP. How would I go about doing this?
I have 2 Columns in the Table, MessageID(auto) & Message.
I already know how to connect to the database.
Use mysql_query:
<?php
$result = mysql_query('SELECT t.messageid, t.message
FROM TABLE t
ORDER BY t.messageid DESC
LIMIT 1') or die('Invalid query: ' . mysql_error());
//print values to screen
while ($row = mysql_fetch_assoc($result)) {
echo $row['messageid'];
echo $row['message'];
}
// Free the resources associated with the result set
// This is done automatically at the end of the script
mysql_free_result($result);
?>
The SQL query:
SELECT t.messageid, t.message
FROM TABLE t
ORDER BY t.messageid DESC
LIMIT 1
...uses the ORDER BY to set the values so the highest value is the first row in the resultset. The LIMIT says that of all those rows, only the first is actually returned in the resultset. Because messageid is auto-increment, the highest value is the most recent one...
Records in a relational database do not have an intrinsic "order" so you cannot fetch the "last" record without some kind of ORDER BY clause.
Therefore, in order to fetch the "last" record, simply reverse the ORDER BY clause (change ASC to DESC or vice versa) then select the first result.
If you have an auto-increment field and you just want to find the last value that was inserted, you can use the fact that the auto-increment fields are ever-increasing (therefore the "last" one will be the one with the highest value) and do something like this:
SELECT *
FROM my_table
ORDER BY id_field DESC
LIMIT 1
Of course you can select the last row by sorting DESC in your query. But what if you want to select the first row and then the last. You can run a new query, but you can also use the function mysql_data_seek. check code below:
$result = mysql_query('YOUR QUERY') or die('Invalid query: ' . mysql_error());
$row_first = mysql_fetch_array($result);
mysql_data_seek($result , (mysql_num_rows($result)-1));
$row_last = mysql_fetch_array($result);
Hope this helps
The MySql query would look like this:
select MessageID, Message
from Table
order by MessageID desc
limit 1;
I am too rusty with PHP to give you the right syntax for executing this.
This query works because you have an auto-incrementing identifying field (MessageID). By ordering the results by that field in descending (largest to smallest) order we are effectively returning the records in the table in reverse order. The limit 1 clause simply limits the result set to one record - the last one in the table.
What do you mean by "the last result"? You need to precise a bit more.
Do you mean "the last entry I registered"?
In this case you should use the appropriate method (depending on the extension you are using) mysqli->insert_id OR mysql_insert_id.
If you mean "the latest entry in the table", an SQL query such as Andrew Hare's is just what you need.
Do you mean the last record or do you need the id of the most recently inserted record? For that you would use the PHP mysql_insert_id() function. Or if you are using the myusqli extension use $mysqli->insert_id.
for some reason (which I don't know why), my boss force me to get the data in this way:
$message_arr = array();
while ($row = mysql_fetch_assoc($result)) {
$message_arr['messageid']= $row['messageid'];
$message_arr['message']= $row['message'];
}
return $message_arr;
Of course, you need everything from OMG Ponies's answer I'm just telling you another way to do it =)
I hope this help.
You should use SELECT query. How SELECT works.
SELECT * FROM table - selects everything in a table (id, row 1, row 2,...)
SELECT id FROM table - selects only particular row from table.
If you now know, how to select, you can use additional logic.
SELECT * FROM table ORDER by id DESC LIMIT 1;
selects everything from table table, orders it by id - orders it DESCENDING and limits the query to only one result.
If you would do it like this:
SELECT * FROM table ORDER by id ASC limit 1; - you would get 1 entry into database.
You can order it by any row you want.
Hope it helps.
One thing to remember is that data does not get saved in the insertion order in any MYSQL database. So in order to get the last entered record u will have to have an auto increment field. Since there is an auto increment field in this table we are good to go.
The below script will help to get the last entered record
<?php
$sql = "SELECT * FROM table_name ORDER BY MessageID DESC LIMIT 2";
$result_set = mysql_query($sql);
if($result_set){
while($row = mysql_fetch_array($result_set)) {
echo "Message Id: ".$row['MessageID']."<br>";
echo "Message: ".$row['Message']."<br>";
}
//creating alert
echo "<script type=\"text/javascript\">alert('Data was Retrieved
successfully');</script>";
}
else{
//creating alert
echo "<script type=\"text/javascript\">alert('ERROR! Could Not Retrieve
Data');</script>";
}
?>
The query selects all the records in the table and orders them according to the descending order of the MessageID (as it is the auto increment field) and limits the returned result to only one record. So since the table is ordered according to the descending order of the MessageID only the last entered record will be returned.
NOTE: if you are using a newer version you will have to use mysqli_query($connection_variable,$sql); instead of mysql_query($sql); and mysqli_fetch_array($result_set) instead of mysql_fetch_array($result_set)
$result = mysql_query('select max(id) from your_table ') or die('Invalid query: ' . mysql_error());
while ($row = mysql_fetch_assoc($result)) {
echo $row['id'];
echo $row['message'];
}
//
//
mysql_free_result($result);
simple like that
this code of php works fine
SELECT t.messageid, t.message
FROM TABLE t
ORDER BY t.messageid DESC
LIMIT 1
if you don't have concurrent entries going into some table.b'cause concurrent entries may not go in accordance of their insertion order.
$statement = $PDO->prepare("
SELECT MessageID,
Message
FROM myTable
ORDER BY MessageID DESC
LIMIT 1;
");
$statement->execute();
$result = $statement->fetch(\PDO::FETCH_ASSOC);
echo $result['MessageID']." and ".$result['Message'];