PHP PDOStatement::getColumnMeta() Method: Usage and Examples

Returns driver-specific metadata for a result column when supported.

The objective is to understand the behavior and operational limits, not only the method name.

What It Does

Returns driver-specific metadata for a result column when supported.

Syntax and Return Value

PDOStatement::getColumnMeta(Parameter #0 [ <required> int $column ]): mixed

The return value and exceptional cases depend on the call described here: Metadata structure and support are not portable; do not infer security-critical validation rules from it.

Example 1: Basic Use

The statement has a real query and result set; database-specific metadata and statement options may be unsupported.

<?php
$pdo = new PDO('sqlite::memory:', null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
$pdo->exec('CREATE TABLE products (id INTEGER PRIMARY KEY, name TEXT NOT NULL, price INTEGER NOT NULL, active INTEGER)');
$pdo->exec("INSERT INTO products (id,name,price,active) VALUES (1,'Desk',120,1),(2,'Lamp',35,1),(3,'Chair',85,0)");
$stmt = $pdo->query("SELECT id, name FROM products");
$meta = $stmt->getColumnMeta(1);
echo $meta["name"] ?? "unavailable";

Example 2: A Second Scenario

The statement has a real query and result set; database-specific metadata and statement options may be unsupported. This additional check distinguishes the method's result from connection or statement state.

<?php
$pdo = new PDO('sqlite::memory:', null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
$pdo->exec('CREATE TABLE products (id INTEGER PRIMARY KEY, name TEXT NOT NULL, price INTEGER NOT NULL, active INTEGER)');
$pdo->exec("INSERT INTO products (id,name,price,active) VALUES (1,'Desk',120,1),(2,'Lamp',35,1),(3,'Chair',85,0)");
$stmt = $pdo->query("SELECT id, name FROM products");
$meta = $stmt->getColumnMeta(1);
echo $meta["name"] ?? "unavailable";
echo json_encode($stmt->getColumnMeta(0));

Example 3: Practical Checks

The statement has a real query and result set; database-specific metadata and statement options may be unsupported. This additional check distinguishes the method's result from connection or statement state.

<?php
$pdo = new PDO('sqlite::memory:', null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
$pdo->exec('CREATE TABLE products (id INTEGER PRIMARY KEY, name TEXT NOT NULL, price INTEGER NOT NULL, active INTEGER)');
$pdo->exec("INSERT INTO products (id,name,price,active) VALUES (1,'Desk',120,1),(2,'Lamp',35,1),(3,'Chair',85,0)");
$stmt = $pdo->query("SELECT id, name FROM products");
$meta = $stmt->getColumnMeta(1);
echo $meta["name"] ?? "unavailable";
echo $stmt->getColumnMeta(1)["name"] ?? "no metadata";

Important Behavior and Edge Cases

Metadata structure and support are not portable; do not infer security-critical validation rules from it.

For production use, also account for error handling, data validation, resource limits and environment-specific driver behavior.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Returns driver-specific metadata for a result column when supported.
• Metadata structure and support are not portable; do not infer security-critical validation rules from it.
• columnCount returns only the number of result columns.

Choose this API or pattern when its exact semantics match your task, and verify the result against the database driver and runtime used by your application.