I want to get the difference between two date in my query. I tried using multiple select statement but it's not working
Here's my code
$tbl_name = "myTable";
$setDay = "10";
$stmt = $pdo->query("SELECT * (
SELECT due_date,
date_paid,
DATEDIFF(due_date, date_paid) as date_interval)
FROM $tbl_name
WHERE DATEDIFF(due_date, date_paid) <= $setDay
ORDER BY trans_id DESC LIMIT $start, $limit");
$stmt->execute();
Thanks
It is important to develop you MySQL queries and perfect them outside the context of PHP code first, then integrate the query once you have it working the way you need it to in a MySQL client application like MySQL Workbench, PHPMyAdmin, etc.
In your query, the outer SELECT is not needed, and the inner query itself looks almost correct, but it is the way you attempt to execute it with PDO that is faulty.
SELECT
due_date,
date_paid,
DATEDIFF(due_date, date_paid) as date_interval
FROM $tbl_name
WHERE
DATEDIFF(due_date, date_paid) <= $setDay
ORDER BY trans_id DESC
LIMIT $start, $limit
Now to execute it in PDO, you should be using prepare()/bindParam()/execute() to create a prepared statement, bind in parameters, and execute it with those parameters (you cannot bind the table name though - that must remain a variable). In your current code, you have a mixup of the the PDO::query() method used for simple static queries and the PDOStatement::execute() method which is used to execute a prepared statement. You should be using the prepared statement method, rather than query().
// Setup the statement with named parameters like :setDay
$sql = "
SELECT
due_date,
date_paid,
DATEDIFF(due_date, date_paid) as date_interval
FROM $tbl_name
WHERE
DATEDIFF(due_date, date_paid) <= :setDay
ORDER BY trans_id DESC
LIMIT :start, :limit
";
// Make PDO throw useful errors on failure
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
// Prepare the statement
$stmt = $pdo->prepare($sql);
// Bind your 3 parameters and execute it
$stmt->bindParam(':setDay', $setDay, PDO::PARAM_INT);
$stmt->bindParam(':start', $start, PDO::PARAM_INT);
$stmt->bindParam(':limit', $limit, PDO::PARAM_INT);
$stmt->execute();
// Fetch your rows returned from the query
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
// Do something with them
print_r($rows);
I always recommend spending time with this PDO tutorial for MySQL developers which places PDO's usage in context of the old mysql_*() API you may already be familiar with.
Try this,
SELECT * , (select (DATEDIFF(due_date,date_paid)) AS date_interval) FROM $tbl_name
Use this to find the date defference,
$diff=date_diff($date1,$date2);
Related
This is my PHP PDO Code
$stmt = $conn->prepare("SELECT * FROM TABLE
WHERE tag1 IN ('$tag1','$tag2') $andor tag2 IN ('$tag1','$tag2 ') ORDER BY $sort DESC LIMIT $limit OFFSET $start");
// Then fire it up
$stmt->execute();
// Pick up the result as an array
$result = $stmt->fetchAll();
// Now you run through this array in many ways, for example
I am trying to convert it into prepared statements, but I really don't understand, how it will work. I tried a lot of things from Google, but nothing worked.
$stmt = $conn->prepare("SELECT * FROM table WHERE tag1=? OR tag1=? AND tag2=? OR tag2=? ORDER BY id DESC LIMIT 15,10");
$stmt->execute(array($tag1, $tag2, $tag1, $tag2));
$result = $stmt->fetch(PDO::FETCH_ASSOC);
I hope it works.
I'm very new to PHP and MySQL, and I'm having trouble performing a prepared statement.
This query returns data exactly as I expect it to:
$result = $con->query('SELECT * FROM users WHERE email="' . $user->user_email . '" LIMIT 1');
However, when forming the query into a prepared statement,
$stmt = $con->prepare('SELECT * FROM users WHERE email=? LIMIT 1');
$stmt->bind_param('s', $user->user_email);
$result = $stmt->execute();
I get no results every time. Is there something wrong with the way I'm preparing the statement?
This question already has an answer here:
Invalid Parameter Number. Parameter not defined
(1 answer)
Closed 8 years ago.
Here is my code
$sql3= "select *
from comments
where status=:status
limit=:limit
offset=:offset
order by time desc";
$query3= $pdo->prepare($sql3);
$query3->bindValue(":status",'n');
$query3->bindValue(":limit",$per_page);
$query3->bindValue(":offest",$offset);
$query3->execute();
$comments=$query3->fetchall();
Here comments is my table name status and time is two column in my table . Whenever I run this code , It shows a warning
Warning: PDOStatement::execute(): SQLSTATE[HY093]: Invalid parameter number: parameter was not defined in E:\XAMPP\htdocs\parlament\user\logged_in_area.php
What does this mean ?
The answer depends of what are limit and offset.
If they're columns names...
You can't use these reserved keywords for column names without backticks
You need to add a AND / OR operator between your lines
$sql3= "select *
from comments
where status=:status
and `limit`=:limit
and `offset`=:offset
order by time desc";
$query3= $pdo->prepare($sql3);
$query3->bindValue(":status", 'n');
$query3->bindValue(":limit", $per_page);
$query3->bindValue(":offest", $offset);
$query3->execute();
$comments=$query3->fetchall();
If they're keywords...
The syntax is LIMIT <n>, not LIMIT = <n> (same for OFFSET)
It better to specify their type with PDO::PARAM_INT (same for OFFSET)
ORDER BY must be added before LIMIT and OFFSET
$sql3= "select *
from comments
where status=:status
order by time desc
limit :limit
offset :offset";
$query3= $pdo->prepare($sql3);
$query3->bindValue(":status", 'n');
$query3->bindValue(":limit", (int)$per_page, PDO::PARAM_INT);
$query3->bindValue(":offset", (int)$offset, PDO::PARAM_INT);
$query3->execute();
$comments=$query3->fetchall();
Adding my answer because nobody has mentioned this specific part yet...
MySQL is very picky about the data type of LIMIT parameters. You pretty much need to use bindParam(':limit', $per_page, PDO::PARAM_INT). I assume the same for OFFSET.
So, in summary
// because E_WARNING level errors are insufficient
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$stmt = $pdo->prepare('SELECT * FROM `comments` WHERE `status` = :status ORDER BY `time` DESC LIMIT :limit OFFSET :offset');
$stmt->bindValue(':status', 'n');
$stmt->bindParam(':limit', $per_page, PDO::PARAM_INT);
$stmt->bindParam(':offset', $offset, PDO::PARAM_INT); // spelt "offset"
$stmt->execute();
$comments = $stmt->fetchAll(PDO::FETCH_ASSOC);
Try this->
$sql3= "select *
from comments
where status = ?
limit ?
offset ?
order by time desc";
$query3= $pdo->prepare($sql3);
$query3->execute(array('n',$per_page,$offset));
$comments=$query3->fetchall();
Not sure about that but I think that PDO::bindValue / bindParam works with variable references. You cannot set a static value as parameter.
Try to replace
$query3->bindValue(":status",'n');
by
$n_value = 'n';
$query3->bindValue(":status",$n_value);
You also forgot the "AND" Keyword between your conditions
You're missing the AND or OR keyword in statement. Also, LIMIT is a reserved keyword, you'll need to backtick it or rename it to something else if you don't want to do that.
$sql3= "select *
from comments
where status = ?
limit= ?
offset= ?
order by time desc";
$query3= $pdo->prepare($sql3);
$query3->bindValue(1,'n');
$query3->bindValue(2,$per_page);
$query3->bindValue(3,$offset);
$query3->execute();
$comments=$query3->fetchall();
I have this code for selecting fname from the latest record on the user table.
$mysqli = new mysqli(HOST, USER, PASSWORD, DATABASE);
$sdt=$mysqli->('SELECT fname FROM user ORDER BY id DESC LIMIT 1');
$sdt->bind_result($code);
$sdt->fetch();
echo $code ;
I used prepared statement with bind_param earlier, but for now in the above code for first time I want to use prepared statement without binding parameters and I do not know how to select from table without using bind_param(). How to do that?
If, like in your case, there is nothing to bind, then just use query()
$res = $mysqli->query('SELECT fname FROM user ORDER BY id DESC LIMIT 1');
$fname = $res->fetch_row()[0] ?? false;
But if even a single variable is going to be used in the query, then you must substitute it with a placeholder and therefore prepare your query.
However, in 2022 and beyond, (starting PHP 8.1) you can indeed skip bind_param even for a prepared query, sending variables directly to execute(), in the form of array:
$query = "SELECT * FROM `customers` WHERE `Customer_ID`=?";
$stmt = $db->prepare($query);
$stmt->execute([$_POST['ID']]);
$result = $stmt->get_result();
$row = $result->fetch_assoc();
The answer ticked is open to SQL injection. What is the point of using a prepared statement and not correctly preparing the data. You should never just put a string in the query line. The point of a prepared statement is that it is prepared. Here is one example
$query = "SELECT `Customer_ID`,`CompanyName` FROM `customers` WHERE `Customer_ID`=?";
$stmt = $db->prepare($query);
$stmt->bind_param('i',$_POST['ID']);
$stmt->execute();
$stmt->bind_result($id,$CompanyName);
In Raffi's code you should do this
$bla = $_POST['something'];
$mysqli = new mysqli(HOST, USER, PASSWORD, DATABASE);
$stmt = $mysqli->prepare("SELECT `fname` FROM `user` WHERE `bla` = ? ORDER BY `id` DESC LIMIT 1");
$stmt->bind_param('s',$_POST['something']);
$stmt->execute();
$stmt->bind_result($code);
$stmt->fetch();
echo $code;
Please be aware I don't know if your post data is a string or an integer. If it was an integer you would put
$stmt->bind_param('i',$_POST['something']);
instead. I know you were saying without bind param, but trust me that is really really bad if you are taking in input from a page, and not preparing it correctly first.
I'm trying to get results from a query to the database but the LIMIT isn't working. When I put LIMIT 10 it returns no results. Am I missing something here?
Here is my code. I'm trying to figure out what the reason is for this strange behavior.
$username = "derek";
$query = $conn->prepare('SELECT * FROM notifications WHERE (needs=:username OR worker=:username1) ORDER BY CASE WHEN needs=:username2 THEN needsread ELSE workerread END, time DESC LIMIT 10');
$query->bindParam(':username', $username);
$query->bindParam(':username1', $username);
$query->bindParam(':username2', $username);
$query->execute();
Ended up being something with my if statements. I was getting the results but after filtering through my if statements the 10 results I wanted to show shouldn't have shown. So after fixing my query to the database it worked. Here's my query:
$workneed = "workneed";
$follow="follow";
$query = $conn->prepare('SELECT * FROM notifications WHERE CASE WHEN needs=:username THEN type=:workneed END OR CASE WHEN worker=:username THEN type=:follow END ORDER BY CASE WHEN needs=:username THEN needsread ELSE workerread END, time DESC LIMIT 10');
$query->bindParam(':username', $username);
$query->bindParam(':workneed', $workneed);
$query->bindParam(':follow', $follow);
$query->execute();