Laravel ORM Part3

We have discovered eloquent fetching methods in previous parts. It’s time to fine tune query constraints as they add custom rules to our queries.

I hope, You already read collection from start to be familiar with methods discussed here.

Constraints

Where

The where() method used to retrieve table rows by matching value of columns. For example.

Route::get('users', function(){
 //get user where username is mary
 return User::where('username','=','mary')
         ->get();
 //outputs : [{"id":5,"username":"mary",...
});

This method takes three parameters. The first parameter is column name. The second parameter is comparison operator (<[/inline] , <code class='highlight'></code>> , => , =<[/inline]). The third parameter is the value of column. Let's lead with another example but this time i will match part of <code class='highlight'>username</code>.</p>
[php]Route::get('users', function(){
//get user where username begin with m and id more than 1
return User::where('username','LIKE','m%')
->where('id','>','1')
->get();
//outputs : [{"id":2,"username":"mark",..},{"id":5,"username":"mary"...}]
});[/php]
<h4>WhereBetween</h4>
<p>The [inline]whereBetween() method used to retrieve table rows in which column value between two provided values.

Route::get('users', function(){
 //get user where id between 2 and 4
 return User::whereBetween('id',array(2,4))
         ->get();
 //outputs : [{"id":2,..},{"id":3,..},{"id":4,..}]
});

There’s also whereNotBetween() method which is the reverse of whereBetween() method.

WhereRaw

The whereRaw() method used to apply many WHERE conditions to SQL string. For example.

Route::get('users', function(){
 //get user where id is 2  and username begin with m
 return User::whereRaw('id = ? and username LIKE ?',array('2','m%'))
         ->get();
 //outputs : [{"id":2,"username":"mark",...}]
});

OrWhere

This method used as chained to allow another condition to match. here’s an example.

Route::get('users', function(){
 //get user where id is 1 or 2
 return User::where('id','=',1)
         ->orwhere('id','=',2)
         ->get();
 //outputs : [{"id":2,..}] 
 //because there is no user with id =2
});

WhereNested

The whereNested() used to apply multiple where() constraints. It is similar to chained where() constraints.

Route::get('users', function(){
 //get user where id > 1 and username begin with m
 return User::whereNested(function($sQL){
  $sQL->where('id','>',1);
  $sQL->where('username','LIKE','m%');
 })
         ->get();
 //outputs : [{"id":2,..},{"id":4,..},{"id":5,..}]
});

WhereNull

The whereNull() method used to retrieve rows in which provided coulumn has null values. For example.

Route::get('users', function(){
 //get user with username = null
 return User::whereNull('username')
         ->get();
 //outputs : []
});

The whereNotNull() is the reverse.If you used it in this example,you will get all users.

WhereIn

This method is similar to in_array() PHP function but needle will be column values. For example.

Route::get('users', function(){
 //get user with username is mary or john or mike
 return User::whereIn('username', array('mary','john','mike'))
         ->get();
 //outputs : [{"id":5,"username":"mary",..}]
});

The whereNotIn() is the reverse of this method.

OrderBy

This method used to order returned results by value of provided column. The first parameter is the name of the column and the second one is asc or desc.

Route::get('users', function(){
 //get users where id > 1 in desc order
 return User::where('id','>',1)
         ->orderBy('id','desc')
         ->get();
 //outputs : [{"id":7,...},{"id":6,...}...]
});

Take

This method used to limit returned rows.Let’s use this method with last example.

Route::get('users', function(){
 //get users where id > 1 in desc order
 //then get only result
 return User::where('id','>',1)
         ->orderBy('id','desc')
         ->take(1)
         ->get();
 //outputs : [{"id":7,...}]
});

Skip

This method used to provide an offset to returned results.for example

Route::get('users', function(){
 //get users where id > 1 in desc order
 //then get only result after skipping first result
 return User::where('id','>',1)
         ->orderBy('id','desc')
         ->take(1)
         ->skip(1)
         ->get();
 //outputs : [{"id":6,...}]
});

As you can see the first row skipped and second one returned.