Laravel wrap any existing query with or condition - laravel

I have an existing laravel model, with many where conditions chained to it.
i.e WHERE username='john' AND (updated_at > "2017-01-01" OR ... ) AND ...
I don't know how many previous queries there are, and i don't have access to them. I only have access to the model instance after it has received some where conditions.
i.e i have a function that receives a model as its parameter, and i want
to add an OR condition to already existing wheres
function notDeleted($model) {
// model has already a bunch of where/or where conditions at this point
// i want return rows, that match either all the previous conditions
// OR this new condition that i add inside this function.
}
I would like to add an OR condition, in the following way.
Select * from users WHERE ( (query1 AND query2 AND ...) OR deleted_at IS NULL);
if u simply use
->orWhere, then the query will be
select * from users where query1 AND query2 AND ... OR deleted_at is null
Note: the table names, columns etc are made up for SO post, my actual use case is a bit more complicated.

I had a similar problem and this is how I solved it:
// Create new \Illuminate\Database\Query\Builder with current wheres in a group
$new_query = $query_builder->getQuery()->forNestedWhere();
$new_query->addNestedWhereQuery($query_builder->getQuery());
// Add the new query in another group
$new_query->whereIn($fk_field,
function($q) use ($index_name, $args) {
// Ignore the Sphinx stuff, just add your new condition here.
$q->select(\DB::raw(SphinxSearch::getRawSelect($index_name)))
->where('query', SphinxSearch::getRawQueryString($args));
});
// Replace original \Illuminate\Database\Eloquent\Builder's internal
// \Illuminate\Database\Query\Builder with the new one
$query_builder->setQuery($new_query);

Put the criteria you want to wrap in a closure:
$model->where(function($query) {
$query->where('field', 'value')
->where('field2', 'value');
})
->orWhereNull('deleted_at');

Try to wrap where condition like this below
SomeModel::where(function($q){
$q->where(query1 AND query2 AND ...)
->orWhere(deleted_at IS NULL);
})->get();
Above code is just a sample. You need to modify to your requirements.
For more information check this link Nested Parameter Grouping

Related

use a custom function inside a laravel select

I have a query that needs to use a custom function like is showed below.
The problem is that one of the parameters is a value of another field from the same query.
The function is "calcula_distancia" and "$ofps[0]->latitude" and "$ofps[0]->longitude" are fields from a previus query.
The function needs 4 parameters and the last two are field from $necps that is beeing selected, but I can not retrieve the value from it using just 'participantes.latitude' or even without cotes. It passes a string only, to the function.
So, how can I pass the value from this fields beeing selected to the function?
Tryed to use RAW but not work.
Sorry for the big question. thanks! :-)
use App\Classes\MinhasFuncoes;
$mf = new MinhasFuncoes();
$necps = DB::table('necessidades_part')->where('necessidades_part.id_part',"<>",$id_part)
->where(function($query) use ($searchValues){
foreach ($searchValues as $value) {
if(strlen($value)>3){
$query->orwhere('obs','like','%'.($value).'%')
->orwhere('necessidades.descricao','like','%'.($value).'%')
->orwhere('categorias.descricao','like','%'.($value).'%');
}
}
})
->join('participantes','necessidades_part.id_part','=','participantes.id')
->join('necessidades','necessidades_part.id_nec','=','necessidades.id')
->join('categorias','necessidades.id_cat','=','categorias.id')
->join('unidades','necessidades.id_unid','=','unidades.id')
->select('participantes.id as id_part','participantes.nome_part','participantes.latitude',
'participantes.longitude','participantes.nome_part','necessidades_part.id as id_nec_part',
'necessidades_part.id_nec','necessidades_part.quant','necessidades_part.data',
'necessidades_part.obs','necessidades.descricao as desc_nec',
'categorias.descricao as desc_cat','unidades.descricao as desc_unid',
$mf->calcula_distancia($ofps[0]->latitude,$ofps[0]->longitude,'participantes.latitude',
'participantes.longitude').' as distancia')
->orderBy('data','desc')
->paginate(10);
you can not execute your PHP function inside of your DB query. you should use MySQL function instead of that or you should fetch results from the database then map your result just in PHP

changing a query result value according to wherehas condition in laravel

I am using laravel
I want to change the value of a column according to a specific condition.
if a condition is satisfied in wherehas then change the value of specific column to 1 let's say.How could i do it.
if i can call a function in the model inside the wherehas function to change the value how could I do it ??
i can iterate the result set using a 2 for loops and change it, however I want to decrease the complexity by changing the value while retrieving the data
Course::with('stages','stages.levels')->whereHas('stages.levels', function($query)use ($levelsarray){
$query->wherenotIn('id', $levelsarray);
here I want to change a column value in table levels
})->first();
Here is a general way,
Assuming you have Three models, Course, Stage, Level
When you are retrieving data from Level model, add an accessor,
For more info click here.
Eg:
On Level.php model,
public function getColumnNameAttribute($value) // replace ColumnName with column name
{
//write application logic here.
return $value;
}

Select one column with where clause Eloquent

Im using Eloquent. But I'm having trouble understanding Eloquent syntax. I have been searching, and trying this cheat sheet: http://cheats.jesse-obrien.ca, but no luck.
How do i perform this SQL query?
SELECT user_id FROM notes WHERE note_id = 1
Thanks!
If you want a single record then use
Note::where('note_id','1')->first(['user_id']);
and for more than one record use
Note::where('note_id','1')->get(['user_id']);
If 'note_id' is the primary key on your model, you can simply use:
Note::find(1)->user_id
Otherwise, you can use any number of syntaxes:
Note::where('note_id', 1)->first()->user_id;
Note::select('user_id')->where('note_id', 1)->first();
Note::whereNoteId(1)->first();
// or get() will give you multiple results if there are multiple
Also note, in any of these examples, you can also just assign the entire object to a variable and just grab the user_id attribute when needed later.
$note = Note::find(1);
// $user_id = $note->user_id;

laravel database query Does `where` always need `first()`?

I am new to laravel and confused about some query methods.
find($id) is useful and returns a nice array, but sometimes I need to select by other fields rather than id.
The Laravel document said I could use where('field', '=', 'value') and return a bunch of data, which is fine.
What I can't understand is why I need to add ->first() every time, even if I am pretty sure there is only one single row matches the query.
It goes like this:
$query->where(..)->orderBy(..)->limit(..) etc.
// you can chain the methods as you like, and finally you need one of:
->get($columns); // returns Eloquent Collection of Models or array of stdObjects
->first($columns); // returns single row (Eloquent Model or stdClass)
->find($id); // returns single row (Eloquent Model or stdClass)
->find($ids); // returns Eloquent Collection
// those are examples, there are many more like firstOrFail, findMany etc, check the api
$columns is an array of fields to retrieve, default array('*')
$id is a single primary key value
$ids is an array of PKs, this works in find method only for Eloquent Builder
// or aggregate functions:
->count()
->avg()
->aggregate()
// just examples here too
So the method depends on what you want to retrieve (array/collection or single object)
Also the return objects depend on the builder you are using (Eloquent Builder or Query Builder):
User::get(); // Eloquent Colleciton
DB::table('users')->get(); // array of stdObjects
even if I am pretty sure there is only one single row matches the query.
Well Laravel cant read your mind - so you need to tell it what you want to do.
You can do either
User::where('field', '=', 'value')->get()
Which will return all objects that match that search. Sometimes it might be one, but sometimes it might be 2 or 3...
If you are sure there is only one (or you only want the first) you can do
User::where('field', '=', 'value')->first()
get() returns an array of objects (multiple rows)
while
first() returns a single object (a row)
You can of course use get() when you know it will return only one row, but you need to keep that in mind when addressing the result:
using get()
$rez = \DB::table('table')->where('sec_id','=','5')->get();
//will return one row in an array with one item, but will be addressed as:
$myfieldvalue = $rez[0]->fieldname;
using first()
$rez = \DB::table('table')->where('sec_id','=','5')->first();
// will also return one row but without the array, so
$myfieldvalue = $rez->fieldname;
So it depends on how you want to access the result of the query: as an object or as an array, and also depends on what "you know" the query will return.
first() is the equivalent of LIMIT 1 at the end of your SELECT statement. Even if your query would return multiple rows, if you use first() it will only return the first row

Laravel - When to use ->get()

I'm confused as to when ->get() in Laravel...
E.G. DB::table('users')->find(1) doesn't need ->get() to retrieve the results, neither does User::find(1)
The laravel docs say "...execute the query using the get or first method..."
I've read the Fluent Query Builder and Eloquent docs but don't understand when the usage of get() is required...
Thanks for the help
Since the find() function will always use the primary key for the table, the need for get() is not necessary. Because you can't narrow your selection down and that's why it will always just try to get that record and return it.
But when you're using the Fluent Query Builder you can nest conditions as such:
$userQuery = DB::table('users');
$userQuery->where('email', '=', 'foo#bar.com');
$userQuery->or_where('email', '=', 'bar#foo.com');
This allows you to add conditions throughout your code until you actually want to fetch them, and then you would call the get() function.
// Done with building the query
$users = $userQuery->get();
For find(n), you retrieve a row based on the primary key which is 'n'.
For first(), you retrieve the first row among all rows that fit the where clauses.
For get(), you retrieve all the rows that fit the where clauses. (Please note that loops are required to access all the rows or you will get some errors).
find returns one row from the database and represent it as a fluent / eloquent object. e.g. SELECT * FROM users WHERE id = 3 is equivalent to DB::table('users')->find(3);
get returns an array of objects. e.g. SELECT * FROM users WHERE created_at > '2014-10-12' is equivalent to DB::table('users')->where('created_at', '>', '2014-10-12')->get() will return an array of objects containing users where the created at field is newer than 4014-10-12.
The get() method will give you all the values from the database that meet your parameters where as first() gets you just the first result. You use find() and findOrFail() when you are searching for a key. This is how I use them:
When I want all data from a table I use the all() method
Model::all();
When I want to find by the primary key:
Model::find(1)->first();
Or
Model::findOrFail(1)->first();
This will work if there is a row with a primary key of one. It should only retrieve one row so I use first() instead of get(). Remember if you deleted the row that used key 1, or don't have data in your table, your find(1) will fail.
When I am looking for specific data as in a where clause:
Model::where('field', '=', 'value')->get();
When I want only the first value of the data in the where clause.
Model::where('field', '=', 'value')->first();
Basically what you need to understand is that get() return a collection(note that one object can be in the collection but it still a collection) why first() returns the first object from the result of the query(that is it returns an object)
#Take_away
Get() return a collection first() return an object
You can use get() method with latest() method to get the latest record that were recently added to your table
For example
$user=Student::latest()->get();
return all the data in descending order

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