How to Use the PDO::bindValue() Function in PHP

09/06/2021

Contents

In this article, you will learn how to use the PDO::bindValue() function in PHP.

PDO::bindValue() Function

The PDO::bindValue() function is used in PHP to bind a value to a named or positional placeholder in a prepared SQL statement.

Syntax
$stmt->bindValue(parameter, value, data_type);
Parameters
  • $stmt is a PDO statement object obtained by calling PDO::prepare().
  • parameter is either a named placeholder (e.g. :name) or a positional placeholder (e.g. ?) in the prepared SQL statement.
  • value is the value to be bound to the placeholder.

  • data_type is an optional constant that defines how the value should be treated in the SQL statement. It can be one of the following values:

    • PDO::PARAM_BOOL: Treat the value as a boolean.
    • PDO::PARAM_NULL: Treat the value as a null value.
    • PDO::PARAM_INT: Treat the value as an integer.
    • PDO::PARAM_STR: Treat the value as a string.
    • PDO::PARAM_LOB: Treat the value as a large object (BLOB).
    • PDO::PARAM_STMT: Treat the value as a record set (result set).
Example

Here’s an example of how to use the bindValue() function:

<?php
  $db = new PDO("mysql:host=localhost;dbname=testdb", "username", "password");
  $query = "SELECT * FROM users WHERE username = :username";
  $stmt = $db->prepare($query);
  $stmt->bindValue(":username", "john_doe", PDO::PARAM_STR);
  $stmt->execute();
  $result = $stmt->fetchAll();
?>

In this example, the placeholder :username is bound to the value “john_doe” and the data type PDO::PARAM_STR is specified to indicate that the value is a string.

Here’s an example that demonstrates the use of named placeholders and the PDO::PARAM_INT data type:

<?php
  $db = new PDO("mysql:host=localhost;dbname=testdb", "username", "password");
  $query = "SELECT * FROM users WHERE id = :id";
  $stmt = $db->prepare($query);
  $stmt->bindValue(":id", 10, PDO::PARAM_INT);
  $stmt->execute();
  $result = $stmt->fetchAll();
?>

In this example, the named placeholder :id is bound to the value 10 and the data type PDO::PARAM_INT is specified to indicate that the value is an integer.

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