Check if table is already joined in Laravel Query Builder

BaseModel.php

<?php

class BaseModel extends Eloquent {

    public static function isJoined($query, $table)
    {
        $joins = $query->getQuery()->joins;
        if($joins == null) {
            return false;
        }

        foreach ($joins as $join) {
            if ($join->table == $table) {
                return true;
            }
        }

        return false;
    }

}

Thanks for this @goranprijic, and to @BadChoice and @arnoudhgz for the optimizations. I'm using Eloquent separate from Laravel, so I use the make() method on the Collection class directly:

$isJoined = Collection::make($query->getQuery()->joins)->pluck('table')->contains($table);

->contains can also be a callback function. I had to use this as my joined table wasn't just a table name but instead an alias, something like table_name AS permissions_table.

return collect($query->getQuery()->joins)->pluck('table')->contains(function ($value, $key) use ($table) {
    if (is_a($value, Illuminate\Database\Query\Expression::class)) {
        /** @var Illuminate\Database\Query\Expression $value */
        return $value->getValue() === $table; // $table is something like "table_name AS permissions_table"
    }

    return $value === $table;
});

Just throwing in another possible solution that uses native php array functions and thus should have better performance:

return array_search($table, array_column((array)$builder->getQuery()->joins, 'table'));

Be sure to explicitly check the return value for false using ===.

Thanks for this snippet, very useful

This method detects all kinds of joins (leftJoin(), join(), etc.)

Clarifying just in case someone else was wondering!