Query Builder
- Introduction
- Selects
- Joins
- Advanced Wheres
- Aggregates
- Raw Expressions
- Inserts
- Updates
- Deletes
- Unions
- Pessimistic Locking
Introduction
The database query builder provides a convenient, fluent interface to creating and running database queries. It can be used to perform most database operations in your application, and works on all supported database systems.
The Laravel query builder uses PDO parameter binding throughout to protect your application against SQL injection attacks. There is no need to clean strings being passed as bindings.
Selects
Retrieving All Rows From A Table
$users = DB::table('users')->get(); foreach ($users as $user){ var_dump($user->name);}
Chunking Results From A Table
DB::table('users')->chunk(100, function($users){ foreach ($users as $user) { // }});
You may stop further chunks from being processed by returning false
from the Closure
:
DB::table('users')->chunk(100, function($users){ // return false;});
Retrieving A Single Row From A Table
$user = DB::table('users')->where('name', 'John')->first(); var_dump($user->name);
Retrieving A Single Column From A Row
$name = DB::table('users')->where('name', 'John')->pluck('name');
Retrieving A List Of Column Values
$roles = DB::table('roles')->lists('title');
This method will return an array of role titles. You may also specify a custom key column for the returned array:
$roles = DB::table('roles')->lists('title', 'name');
Specifying 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();
Adding A Select Clause To An Existing Query
$query = DB::table('users')->select('name'); $users = $query->addSelect('age')->get();
Using Where Operators
$users = DB::table('users')->where('votes', '>', 100)->get();
Or Statements
$users = DB::table('users') ->where('votes', '>', 100) ->orWhere('name', 'John') ->get();
Using Where Between
$users = DB::table('users') ->whereBetween('votes', [1, 100])->get();
Using Where Not Between
$users = DB::table('users') ->whereNotBetween('votes', [1, 100])->get();
Using Where In With An Array
$users = DB::table('users') ->whereIn('id', [1, 2, 3])->get(); $users = DB::table('users') ->whereNotIn('id', [1, 2, 3])->get();
Using Where Null To Find Records With Unset Values
$users = DB::table('users') ->whereNull('updated_at')->get();
Dynamic Where Clauses
You may even use "dynamic" where statements to fluently build where statements using magic methods:
$admin = DB::table('users')->whereId(1)->first(); $john = DB::table('users') ->first(); $jane = DB::table('users') ->whereNameOrAge('Jane', 22) ->first();
Order By, Group By, And Having
$users = DB::table('users') ->orderBy('name', 'desc') ->groupBy('count') ->having('count', '>', 100) ->get();
Offset & Limit
$users = DB::table('users')->skip(10)->take(5)->get();
Joins
The query builder may also be used to write join statements. Take a look at the following examples:
Basic Join Statement
DB::table('users') ->join('contacts', 'users.id', '=', 'contacts.user_id') ->join('orders', 'users.id', '=', 'orders.user_id') ->select('users.id', 'contacts.phone', 'orders.price') ->get();
Left Join Statement
DB::table('users') ->leftJoin('posts', 'users.id', '=', 'posts.user_id') ->get();
You may also specify more advanced join clauses:
DB::table('users') ->join('contacts', function($join) { $join->on('users.id', '=', 'contacts.user_id')->orOn(...); }) ->get();
If you would like to use a "where" style clause on your joins, you may use the where
and orWhere
methods on a join. Instead of comparing two columns, these methods will compare the column against a value:
DB::table('users') ->join('contacts', function($join) { $join->on('users.id', '=', 'contacts.user_id') ->where('contacts.user_id', '>', 5); }) ->get();
Advanced Wheres
Parameter Grouping
Sometimes you may need to create more advanced where clauses such as "where exists" or nested parameter groupings. The Laravel query builder can handle these as well:
DB::table('users') ->where('name', '=', 'John') ->orWhere(function($query) { $query->where('votes', '>', 100) ->where('title', '<>', 'Admin'); }) ->get();
The query above will produce the following SQL:
select * from users where name = 'John' or (votes > 100 and title <> 'Admin')
Exists Statements
DB::table('users') ->whereExists(function($query) { $query->select(DB::raw(1)) ->from('orders') ->whereRaw('orders.user_id = users.id'); }) ->get();
The query above will produce the following SQL:
select * from userswhere exists ( select 1 from orders where orders.user_id = users.id)
Aggregates
The query builder also provides a variety of aggregate methods, such as count
, max
, min
, avg
, and sum
.
Using Aggregate Methods
$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 in a query. These expressions will be injected into the query as strings, so be careful not to create any SQL injection points! To create a raw expression, you may use the DB::raw
method:
Using A Raw Expression
$users = DB::table('users') ->select(DB::raw('count(*) as user_count, status')) ->where('status', '<>', 1) ->groupBy('status') ->get();
Inserts
Inserting Records Into A Table
DB::table('users')->insert();
Inserting Records Into A Table With An Auto-Incrementing ID
If the table has an auto-incrementing id, use insertGetId
to insert a record and retrieve the id:
$id = DB::table('users')->insertGetId();
When using PostgreSQL the insertGetId method expects the auto-incrementing column to be named "id".
Inserting Multiple Records Into A Table
DB::table('users')->insert([]);
Updates
Updating Records In A Table
DB::table('users') ->where('id', 1) ->update(['votes' => 1]);
Incrementing or decrementing a 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 may also specify additional columns to update:
DB::table('users')->increment('votes', 1, ['name' => 'John']);
Deletes
Deleting Records In A Table
DB::table('users')->where('votes', '<', 100)->delete();
Deleting All Records From A Table
DB::table('users')->delete();
Truncating A Table
DB::table('users')->truncate();
Unions
The query builder also provides a quick way to "union" two queries together:
$first = DB::table('users')->whereNull('first_name'); $users = DB::table('users')->whereNull('last_name')->union($first)->get();
The unionAll
method is also available, and has the same method signature as union
.
Pessimistic Locking
The query builder includes a few functions to help you do "pessimistic locking" on your SELECT statements.
To run the SELECT statement with a "shared lock", you may use the sharedLock
method on a query:
DB::table('users')->where('votes', '>', 100)->sharedLock()->get();
To "lock for update" on a SELECT statement, you may use the lockForUpdate
method on a query:
DB::table('users')->where('votes', '>', 100)->lockForUpdate()->get();