Laravel 5.4: Storing the 'Where' clause in a variable - php

Question

I want to write a dynamic update query in Laravel which accepts arguments and can be used in whole project.
Following is my Controller function:
public function editquery(Request $request)
{
$city_id = $request->input('city_id');
$city_name = $request->input('city_name');
$tbl = 'city';
$data = ['city_name'=>$city_name];
$wher = ('city_id',1);
General_model::editrecord($data,$wher,$tbl);
return redirect()->action('Admin_controller#cities_page')->with('status','Record Updated Successfully!');;
}
Below is my Model function:
public static function editrecord($data,$wher,$tbl)
{
return DB::table($tbl)->where($wher)->update($data);
}
The only problem here is that I cannot store the value ('city_id',1) in the $wher variable. This is the screenshot of the error:
link to the image file
Is there any other way to do this. Please Help.

Answer 1

The where method accepts an array of conditions.
$table = 'city';
$conditions = [
['city_id', '=', '1']
];
$data = ['city_name' => $city_name];
General_model::editRecord($table, $conditions, $data);
// In your model
public static function editRecord($table, $conditions, $data)
{
return DB::table($table)->where($conditions)->update($data);
}
You can also set multiple conditions.
$conditions = [
['city_id', '=', '1'],
['test', '=', 'test'],
];
Edit
This is the default where method
where($column, $operator = null, $value = null, $boolean = 'and')
Setting the fourth parameter to or will make the condition orWhere.
Example
$conditions = [
['city_id', '=', '1'],
['test', '=', 'test', 'or'],
];

Answer 2

You can't do this
public static function editrecord($data,$wher,$tbl)
{
return DB::table($tbl)->where($wher)->update($data);
}
Since, where is a function; it expects 2 or 3 arguments and not just 1 argument.
You will have to pass both the arguments like so
public static function editrecord($data, $where_column, $where_val, $tbl)
{
return DB::table($tbl)->where($where_column, $where_val)
->update($data);
}
Then, in your controller function
$where_column = 'city_id';
$where_val = 1;
General_model::editrecord($data,$where_column,$where_val,$tbl);

Answer 3

Your code is not exactly in the style of Laravel, why would you want to create a separate static function, if such tasks are easily solved by the standard features of Eloquent / Query Builder?
Eloquent example:
app/City.php
<?php
class City extends Model {
protected $table = 'city';
protected $primaryKey = 'city_id';
protected $fillable = ['city_name'];
}
In your controller:
City::findOrFail($city_id)->update([
'city_name' => $city_name
]);
Query Builder example:
DB::table('city')->where(['city_id' => $city_id])->update([
'city_name' => $city_name
]);
This is much easier to read, understand and support than functions that do similar things in an incomprehensible way.