How to use PDO to read data from the database?

Reading data from the database is not so different than inserting data, with steps 1 to 5 being almost identical while the sixth step is different.

1) Write the regular select statement and again, instead of values, put named placeholders. For example:

$sql = "SELECT * FROM users";

1	$sql = "SELECT * FROM users";

2) Prepare the query:

$query = $dbh -> prepare($sql);

1	$query = $dbh -> prepare($sql);

3) Execute the query:

$query -> execute();

1	$query -> execute();

4) Assign the data which you pulled from the database (in the preceding step) to a variable.

$results = $query -> fetchAll(PDO::FETCH_OBJ);

1	$results = $query -> fetchAll(PDO::FETCH_OBJ);

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.

if($query -> rowCount() > 0){}

1	if($query -> rowCount() > 0){}

6) In case that the query returned at least one record, we can echo the records within a foreach loop:

if($query -> rowCount() > 0)
{
foreach($results as $result)
{
echo $result -> name . ", ";
echo $result -> city . ", ";
echo $result -> date_added;
}
}

if($query -> rowCount() > 0)

{

foreach($results as $result)

{

echo $result -> name . ", ";

echo $result -> city . ", ";

echo $result -> date_added;

}

All code together now:

$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;
}
}

$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;

}

For localhost Database name is : pdoanuj
Sql file available inside the package.
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How to use PDO to read data from the database?

About the author

Anuj kumar

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About the author

Anuj kumar

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