Row count with PDO

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There are many conflicting statements around. What is the best way to get the row count using PDO in PHP? Before using PDO, I just simply used mysql_num_rows.

fetchAll is something I won't want because I may sometimes be dealing with large datasets, so not good for my use.

Do you have any suggestions?

Answers

$sql = "SELECT count(*) FROM `table` WHERE foo = ?"; 
$result = $con->prepare($sql); 
$result->execute([$bar]); 
$number_of_rows = $result->fetchColumn();

Not the most elegant way to do it, plus it involves an extra query.

PDO has PDOStatement::rowCount(), which apparently does not work in MySql. What a pain.

From the PDO Doc:

For most databases, PDOStatement::rowCount() does not return the number of rows affected by a SELECT statement. Instead, use PDO::query() to issue a SELECT COUNT(*) statement with the same predicates as your intended SELECT statement, then use PDOStatement::fetchColumn() to retrieve the number of rows that will be returned. Your application can then perform the correct action.

EDIT: The above code example uses a prepared statement, which is in many cases is probably unnecessary for the purpose of counting rows, so:

$nRows = $pdo->query('select count(*) from blah')->fetchColumn(); 
echo $nRows;

Monday, September 12, 2022

tdous-b2932c3a1fb0

The following works for me:

<?php

$pdo = new PDO("mysql:host=localhost;dbname=test", "root", "pass");
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

$stmt = $pdo->prepare("INSERT INTO `null_test` (`can_be_null`) VALUES (:null)");
$stmt->bindValue(":null", null, PDO::PARAM_NULL);

$stmt->execute();

Pass in PHP's null, with type of PDO::PARAM_NULL. Also, make sure your prepare emulation is set to false. That might help.

Sunday, August 7, 2022

mohammad_reza_khahani

lastInsertId() is a method of the PDO class, not the PDOStatement class.

This should work:

$groupID = $dbo->lastInsertId();

Friday, November 18, 2022

jon_rimmer

using mysqli you do it the following way (assuming the mysqli object is already created -- you can also use the procedure methods, just slightly different):

$sql = "SELECT SQL_CALC_FOUND_ROWS *, post.id as pid, bla bla 
        FROM account ORDER BY pid ASC". $eb["array"]['querylimit'];
$result = $mysqli->query($sql);
$TotalRcount = $result->num_rows;
while($row=$result->fetch_assoc()){
    $col1 = $row['col1'];  // col1 is a placeholder for whatever column you are reading
    //read columns
}

Tuesday, September 13, 2022

rastacraz

you should replace

$rowCount = $query->rowCount();

with

$rowCount = $query->fetchColumn();

also, take a look at FOUND_ROWS()

there is no sense in calling fetch_num_rows 2 times, it is enough to do:

$numArticles = $rowCount = $article->fetch_num_rows();

Tuesday, November 15, 2022

ryan_conrad

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Row count with PDO

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