How to use PDO to read data from the database?

1) Write the regular select statement and again, instead of values, put named placeholders. For example:
[code language=”php”]
$sql = "SELECT * FROM users";
[/code]
2) Prepare the query:
[code language=”php”]
$query = $dbh -> prepare($sql);
[/code]
3) Execute the query:
[code language=”php”]
$query -> execute();
[/code]
4) Assign the data which you pulled from the database (in the preceding step) to a variable.
[code language=”php”]
$results = $query -> fetchAll(PDO::FETCH_OBJ);
[/code]
Here I used the parameter PDO::FETCH_OBJ that returns the fetched data as an object. If you’d like to fetch the data in the form of an array, use: PDO::FETCH_ASSOC.
5) Make sure that you were able to retrieve the data from the database, by counting the number of records.
[code language=”php”]
if($query -> rowCount() > 0){}
[/code]
6) In case that the query returned at least one record, we can echo the records within a foreach loop:
[code language=”php”]
if($query -> rowCount() > 0)
{
foreach($results as $result)
{
echo $result -> name . ", ";
echo $result -> city . ", ";
echo $result -> date_added;
}
}
[/code]
All code together now:
[code language=”php”]
$sql = "SELECT * FROM users WHERE city = :city";
$query = $dbh -> prepare($sql);
$query -> bindParam(‘:city’, $city, PDO::PARAM_STR);
$city = "New York";
$query -> execute();
$results = $query -> fetchAll(PDO::FETCH_OBJ);
if($query -> rowCount() > 0)
{
foreach($results as $result)
{
echo $result -> name . ", ";
echo $result -> city . ", ";
echo $result -> date_added;
}
}
[/code]

Rajesh Kumar

I’m Rajesh Kumar, a DevOps, SRE, DevSecOps, Cloud, and Platform Engineering expert passionate about sharing practical knowledge, real-world experiences, and industry best practices. I have worked at Cotocus and regularly write about technology, travel, investing, health, product reviews, and digital marketing through my various platforms.

I publish technical articles at DevOps School, travel stories at Holiday Landmark, stock market insights at Stocks Mantra, health and fitness guidance at My Medic Plus, product reviews at TrueReviewNow, and SEO and digital marketing strategies at Wizbrand.