Laravel framework database CURD operation and usage of coherent operation

Laravel framework database CURD operation, how to use coherent operation
Laravel framework database CURD operation, how to operate coherently. This operability is very convenient and simple. We are here to introduce you to a related tutorial. The specific detailed steps are as follows Text introduction.
Laravel is a simple and elegant PHP Web development framework (PHP Web Framework). It can free you from messy codes like noodles; it can help you build a perfect network APP, and every line of code can be concise and expressive.
1. Selects
Retrieve all rows in the table
$users = DB::table('users')->get();
foreach ($users as $user)
{
var_dump($user-> name);
}
Retrieve a single row from a table
$user = DB::table('users')->where('name', 'John')->first();
var_dump($user- >name);
Retrieve rows for a single column
$name = DB::table('users')->where('name', 'John')->pluck('name');
Retrieve a Column value list
$roles = DB::table('roles')->lists('title');
This method will return the role of an array title. You can also specify a custom key column to return the array
$roles = DB::table('roles')->lists('title', 'name');

Specify a Select clause
$users = DB::table('users')->select('name', 'email')->get();
$users = DB::table('users')->distinct()- >get();
$users = DB::table('users')->select('name as user_name')->get();
Select clause is added to an existing query
$ query = DB::table('users')->select('name');
$users = $query->addSelect('age')->get();
where
$users = DB ::table('users')->where('votes', '>', 100)->get();
OR
$users = DB::table('users')->where ('votes', '>', 100)->orWhere('name', 'John')->get();

Where Between
$users = DB::table('users')- >whereBetween('votes', array(1, 100))->get();

Where Not Between
$users = DB::table('users')->whereNotBetween('votes', array (1, 100))->get();

Where In With An Array
$users = DB::table('users')->whereIn('id', array(1, 2, 3) )->get();
$users = DB::table('users')->whereNotIn('id', array(1, 2, 3))->get();

Using Where Null To Find Records With Unset Values
$users = DB::table('users')->whereNull('updated_at')->get();

Order By, Group By, And Having
$users = DB::table('users')->orderBy('name', 'desc')->groupBy('count')->having('count', '>', 100)-> get();
Offset & Limit
$users = DB::table('users')->skip(10)->take(5)->get();
2. Connection
Joins
query Builders can also be used to write join statements. Take a look at the following example:
DB::table('users')
->join('contacts', 'users.id', '=', 'contacts.user_id')
->join('orders ', 'users.id', '=', 'orders.user_id')
->select('users.id', 'contacts.phone', 'orders.price')
->get();
Left join statement
DB::table('users')
->leftJoin('posts', 'users.id', '=', 'posts.user_id')
->get();
DB ::table('users')
->join('contacts', function($join)
{
$join->on('users.id', '=', 'contacts.user_id')- >orOn(...);
})
->get();
DB::table('users')
->join('contacts', function($join)
{
$join ->on('users.id', '=', 'contacts.user_id')
->where('contacts.user_id', '>', 5);
})
->get( );

3. Grouping
Sometimes, you may need to create more advanced where clauses, such as "exists" or nested parameter grouping. Laravel query builder can handle these:
DB::table('users')
->where('name', '=', 'John')
->orWhere(function($query)
{
$ query->where('votes', '>', 100)
->where('title', '<>', 'Admin');
})
->get();

The above query will produce the following SQL:
select * from users where name = 'John' or (votes > 100 and title
<> 'Admin')
Exists Statements
DB::table('users' )
->whereExists(function($query)
{
$query->select(DB::raw(1))
->from('orders')
->whereRaw('orders.user_id = users.id');
})
->get ();
The above query will generate the following SQL:
select * from userswhere exists (
select 1 from orders where orders.user_id = users.id
)

Four. Aggregation
The query builder also provides various aggregation methods , such as statistics, max, min, avg and sum.
$users = DB::table('users')->count();
$price = DB::table('orders')->max('price');
$price = DB:: table('orders')->min('price');
$price = DB::table('orders')->avg('price');
$total = DB::table('users ')->sum('votes');
Raw Expressions
Sometimes you may need to use a raw expression query. These expressions will be injected into the query string, so be careful not to create any SQL injection points! To create a raw expression, you can use DB:rawmethod:
Using A Raw Expression
$users = DB::table('users')
->select(DB::raw('count(*) as user_count, status'))
->where('status', '<>', 1)
->groupBy('status' )
->get();

Increment or decrement the value of a column

DB::table('users')->increment('votes');
DB::table('users')- >increment('votes', 5);
DB::table('users')->decrement('votes');
DB::table('users')->decrement('votes', 5);

You can also specify additional column updates:

DB::table('users')->increment('votes', 1, array('name' => 'John'));

Inserts
Insert records into the table
DB::table('users')->insert(
array('email' => 'john@example.com', 'votes' => 0)
) ;

Inserting records into a table with auto-incrementing ID
If the table, has an auto-incrementing id field use insertGetId to insert a record and retrieve the id:

$id = DB::table('users')->insertGetId(
array('email' => 'john@example.com', 'votes' => 0)
);

Note: When using the PostgreSQL insertGetId method it is expected that the auto-incrementing column will be named is "id".
Multiple records are inserted into the table
The code is as follows:
DB::table('users')->insert(array(
array('email' => 'taylor@example.com', 'votes' = > 0),
array('email' => 'dayle@example.com', 'votes' => 0),
));

4. Updates
Update records in a table
The code is as follows :
DB::table('users')
->where('id', 1)
->update(array('votes' => 1));

5. Deletes
Delete the table The record
code is as follows:
DB::table('users')->where('votes', '<', 100)->delete();

Delete all records in the table
The code is as follows :
DB::table('users')->delete();
Delete a table

The code is as follows:

DB::table('users')->truncate();

6. Unions
The query builder also provides a quick way to "union" two queries:

The code is as follows:
$first = DB::table('users')->whereNull('first_name');
$ users =
DB::table('users')->whereNull('last_name')->union($first)->get();

unionAll method is also available and has the same method signature.
Pessimistic Locking
The query builder includes some "pessimistic locking" features to help you with your SELECT statements. Run the SELECT statement "Shared Lock", you can use the sharedLock method to query:
The code is as follows:
DB::table('users')->where('votes', '>',
100)->sharedLock ()->get();
Update "lock" in a SELECT statement, you can use the lockForUpdate method to query:

The code is as follows:

DB::table('users')->where('votes' , '>', 100)->lockForUpdate()->get();

7. Cache query
You can easily cache the results of the query using mnemonics:
The code is as follows:
$users = DB: :table('users')->remember(10)->get();
In this example, the results of the query will be cached for ten minutes. When query results are cached, they are not run against the database and the results will be loaded from the default cache driver specified by your application. If you are using a driver that supports caching, you can also add tags to cache:

The code is as follows:

$users = DB::table('users')->cacheTags(array('people', 'authors' ))->remember(10)->get();