SHOW COLUMNS — Trust Nothing, Verify Everything

Working with an unfamiliar database or inherited codebase? Don’t guess column names — inspect the schema directly with SHOW COLUMNS.

I recently wasted 20 minutes debugging a query that referenced projects.title when the actual column was projects.name. One SQL command would have caught it:

SHOW COLUMNS FROM projects;

This returns the table’s structure:

+-------------+--------------+------+-----+---------+----------------+
| Field       | Type         | Null | Key | Default | Extra          |
+-------------+--------------+------+-----+---------+----------------+
| id          | int(11)      | NO   | PRI | NULL    | auto_increment |
| name        | varchar(255) | NO   |     | NULL    |                |
| status      | varchar(50)  | YES  |     | active  |                |
| created_at  | timestamp    | YES  |     | NULL    |                |
+-------------+--------------+------+-----+---------+----------------+

Use It Programmatically

In Laravel, you can inspect schemas at runtime:

$columns = DB::select('SHOW COLUMNS FROM ' . $table);

foreach ($columns as $col) {
    echo "{$col->Field} ({$col->Type})\n";
}

This is especially useful for:

• Schema validation: Verify migrations match production
• Legacy databases: Document undocumented systems
• Dynamic queries: Build column lists programmatically
• Debugging: Confirm column existence before querying

Alternative: Laravel’s Schema Facade

Laravel provides a cleaner API for this:

use Illuminate\Support\Facades\Schema;

// Check if column exists
if (Schema::hasColumn('projects', 'title')) {
    // Safe to use
}

// Get all columns
$columns = Schema::getColumnListing('projects');
// ['id', 'name', 'status', 'created_at', 'updated_at']

But SHOW COLUMNS gives you more metadata (type, nullable, defaults) when you need it. Way more reliable than assuming your migrations match production after years of hotfixes.