CODEWITHSUNDEEP
phpdatabasecodeigniter
Abbas Raza
Abbas Raza

Reputation: 71

How to write database queries in helper in CodeIgniter 4

I am using CodeIgniter 4. First I write this to get records from the database, but this shows me an error ( Call to a member function table() on null)

$CI = & get_instance();
$CI -> db -> select('*');
$CI -> db -> from($table_name);

Then I read from documentation and write this

$db->table("tablename");

But this method also failed.

Upvotes: 4

Views: 4079

Answers (2)

Umair Hanif
Umair Hanif

Reputation: 174

//initialize database connection
$db  = \Config\Database::connect();

//created builder to get queries results
$builder = $db->table('users');

//select particular columns
$builder->select('id','first_name','last_name');

//if you want to select all columns
$builder->select('*')

//if you want to put where
$builder->where('id',1);

//if you want to put order by desc or asc
$builder->orderBy('id desc');

//get records
$output = $builder->get();

//if you want to return your results in array format then,
return $output->getResultArray();

//if you want to return your results in std object then,
return $output->getResult();

Upvotes: 0

Muhammad Saquib Shaikh
Muhammad Saquib Shaikh

Reputation: 298

The Query Builder is loaded through the table() method on the database connection. This sets the FROM portion of the query for you and returns a new instance of the Query Builder class:

$db      = \Config\Database::connect();
$builder = $db->table('users');
//loading query builder

$output = $builder->table('table_name')
        ->get();
// Produces: SELECT * FROM table_name

To get result as array you can add one more line of code.

$output = $output->getResultArray();

For selecting particular fileds.

$db = \Config\Database::connect();
$builder = $db->table('users');
//loading query builder

$output = $builder->table('table_name')
        ->select('filedname2, fieldname2, fieldname3,..')
        ->get();
$output = $output->getResultArray();

You can use where clause also for more details refer to codeigniter4 documentation page. https://codeigniter4.github.io/userguide/database/query_builder.html#looking-for-specific-data

Upvotes: 2

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