Database: Query Builder

Introduction
Running Database Queries
- Chunking Results
- Aggregates
Select Statements
Raw Expressions
Joins
Unions
Basic Where Clauses
Advanced Where Clauses
- Where Exists Clauses
- Subquery Where Clauses
Ordering, Grouping, Limit & Offset
Conditional Clauses
Insert Statements
- Upserts
Update Statements
- Updating JSON Columns
- Increment & Decrement
Delete Statements
Pessimistic Locking
Debugging

Introduction

Laravel's 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 perfectly with all of Laravel's supported database systems.

The Laravel query builder uses PDO parameter binding to protect your application against SQL injection attacks. There is no need to clean or sanitize strings passed to the query builder as query bindings.

{note} PDO does not support binding column names. Therefore, you should never allow user input to dictate the column names referenced by your queries, including "order by" columns.

Running Database Queries

Retrieving All Rows From A Table

You may use the table method provided by the DB facade to begin a query. The table method returns a fluent query builder instance for the given table, allowing you to chain more constraints onto the query and then finally retrieve the results of the query using the get method:

<?php

namespace App\Http\Controllers;

use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\DB;

class UserController extends Controller
{
    /**
     * Show a list of all of the application's users.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        $users = DB::table('users')->get();

        return view('user.index', ['users' => $users]);
    }
}

The get method returns an Illuminate\Support\Collection containing the results of the query where each result is an instance of the PHP stdClass object. You may access each column's value by accessing the column as a property of the object:

use Illuminate\Support\Facades\DB;

$users = DB::table('users')->get();

foreach ($users as $user) {
    echo $user->name;
}

{tip} Laravel collections provide a variety of extremely powerful methods for mapping and reducing data. For more information on Laravel collections, check out the collection documentation.

Retrieving A Single Row / Column From A Table

If you just need to retrieve a single row from a database table, you may use the DB facade's first method. This method will return a single stdClass object:

$user = DB::table('users')->where('name', 'John')->first();

return $user->email;

If you don't need an entire row, you may extract a single value from a record using the value method. This method will return the value of the column directly:

$email = DB::table('users')->where('name', 'John')->value('email');

To retrieve a single row by its id column value, use the find method:

$user = DB::table('users')->find(3);

Retrieving A List Of Column Values

If you would like to retrieve an Illuminate\Support\Collection instance containing the values of a single column, you may use the pluck method. In this example, we'll retrieve a collection of role titles:

use Illuminate\Support\Facades\DB;

$titles = DB::table('users')->pluck('title');

foreach ($titles as $title) {
    echo $title;
}

You may specify the column that the resulting collection should use as its keys by providing a second argument to the pluck method:

$titles = DB::table('users')->pluck('title', 'name');

foreach ($titles as $name => $title) {
    echo $title;
}

Chunking Results

If you need to work with thousands of database records, consider using the chunk method provided by the DB facade. This method retrieves a small chunk of results at a time and feeds each chunk into a closure for processing. For example, let's retrieve the entire users table in chunks of 100 records at a time:

use Illuminate\Support\Facades\DB;

DB::table('users')->orderBy('id')->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')->orderBy('id')->chunk(100, function ($users) {
    // Process the records...

    return false;
});

If you are updating database records while chunking results, your chunk results could change in unexpected ways. If you plan to update the retrieved records while chunking, it is always best to use the chunkById method instead. This method will automatically paginate the results based on the record's primary key:

DB::table('users')->where('active', false)
    ->chunkById(100, function ($users) {
        foreach ($users as $user) {
            DB::table('users')
                ->where('id', $user->id)
                ->update(['active' => true]);
        }
    });

{note} When updating or deleting records inside the chunk callback, any changes to the primary key or foreign keys could affect the chunk query. This could potentially result in records not being included in the chunked results.

Aggregates

The query builder also provides a variety of methods for retrieving aggregate values like count, max, min, avg, and sum. You may call any of these methods after constructing your query:

use Illuminate\Support\Facades\DB;

$users = DB::table('users')->count();

$price = DB::table('orders')->max('price');

Of course, you may combine these methods with other clauses to fine-tune how your aggregate value is calculated:

$price = DB::table('orders')
                ->where('finalized', 1)
                ->avg('price');

Determining If Records Exist

Instead of using the count method to determine if any records exist that match your query's constraints, you may use the exists and doesntExist methods:

if (DB::table('orders')->where('finalized', 1)->exists()) {
    // ...
}

if (DB::table('orders')->where('finalized', 1)->doesntExist()) {
    // ...
}

Select Statements

Specifying A Select Clause

You may not always want to select all columns from a database table. Using the select method, you can specify a custom "select" clause for the query:

use Illuminate\Support\Facades\DB;

$users = DB::table('users')
            ->select('name', 'email as user_email')
            ->get();

The distinct method allows you to force the query to return distinct results:

$users = DB::table('users')->distinct()->get();

If you already have a query builder instance and you wish to add a column to its existing select clause, you may use the addSelect method:

$query = DB::table('users')->select('name');

$users = $query->addSelect('age')->get();

Raw Expressions

Sometimes you may need to insert an arbitrary string into a query. To create a raw string expression, you may use the raw method provided by the DB facade:

$users = DB::table('users')
             ->select(DB::raw('count(*) as user_count, status'))
             ->where('status', '<>', 1)
             ->groupBy('status')
             ->get();

{note} Raw statements will be injected into the query as strings, so you should be extremely careful to avoid creating SQL injection vulnerabilities.

Raw Methods

Instead of using the DB::raw method, you may also use the following methods to insert a raw expression into various parts of your query. Remember, Laravel can not guarantee that any query using raw expressions is protected against SQL injection vulnerabilities.

`selectRaw`

The selectRaw method can be used in place of addSelect(DB::raw(...)). This method accepts an optional array of bindings as its second argument:

$orders = DB::table('orders')
                ->selectRaw('price * ? as price_with_tax', [1.0825])
                ->get();

`whereRaw / orWhereRaw`

The whereRaw and orWhereRaw methods can be used to inject a raw "where" clause into your query. These methods accept an optional array of bindings as their second argument:

$orders = DB::table('orders')
                ->whereRaw('price > IF(state = "TX", ?, 100)', [200])
                ->get();

`havingRaw / orHavingRaw`

The havingRaw and orHavingRaw methods may be used to provide a raw string as the value of the "having" clause. These methods accept an optional array of bindings as their second argument:

$orders = DB::table('orders')
                ->select('department', DB::raw('SUM(price) as total_sales'))
                ->groupBy('department')
                ->havingRaw('SUM(price) > ?', [2500])
                ->get();

`orderByRaw`

The orderByRaw method may be used to provide a raw string as the value of the "order by" clause:

$orders = DB::table('orders')
                ->orderByRaw('updated_at - created_at DESC')
                ->get();

`groupByRaw`

The groupByRaw method may be used to provide a raw string as the value of the group by clause:

$orders = DB::table('orders')
                ->select('city', 'state')
                ->groupByRaw('city, state')
                ->get();

Joins

Inner Join Clause

The query builder may also be used to add join clauses to your queries. To perform a basic "inner join", you may use the join method on a query builder instance. The first argument passed to the join method is the name of the table you need to join to, while the remaining arguments specify the column constraints for the join. You may even join multiple tables in a single query:

use Illuminate\Support\Facades\DB;

$users = DB::table('users')
            ->join('contacts', 'users.id', '=', 'contacts.user_id')
            ->join('orders', 'users.id', '=', 'orders.user_id')
            ->select('users.*', 'contacts.phone', 'orders.price')
            ->get();

Left Join / Right Join Clause

If you would like to perform a "left join" or "right join" instead of an "inner join", use the leftJoin or rightJoin methods. These methods have the same signature as the join method:

$users = DB::table('users')
            ->leftJoin('posts', 'users.id', '=', 'posts.user_id')
            ->get();

$users = DB::table('users')
            ->rightJoin('posts', 'users.id', '=', 'posts.user_id')
            ->get();

Cross Join Clause

You may use the crossJoin method to perform a "cross join". Cross joins generate a cartesian product between the first table and the joined table:

$sizes = DB::table('sizes')
            ->crossJoin('colors')
            ->get();

Advanced Join Clauses

You may also specify more advanced join clauses. To get started, pass a closure as the second argument to the join method. The closure will receive a Illuminate\Database\Query\JoinClause instance which allows you to specify constraints on the "join" clause:

DB::table('users')
        ->join('contacts', function ($join) {
            $join->on('users.id', '=', 'contacts.user_id')->orOn(...);
        })
        ->get();

If you would like to use a "where" clause on your joins, you may use the where and orWhere methods provided by the JoinClause instance. 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();

Subquery Joins

You may use the joinSub, leftJoinSub, and rightJoinSub methods to join a query to a subquery. Each of these methods receives three arguments: the subquery, its table alias, and a closure that defines the related columns. In this example, we will retrieve a collection of users where each user record also contains the created_at timestamp of the user's most recently published blog post:

$latestPosts = DB::table('posts')
                   ->select('user_id', DB::raw('MAX(created_at) as last_post_created_at'))
                   ->where('is_published', true)
                   ->groupBy('user_id');

$users = DB::table('users')
        ->joinSub($latestPosts, 'latest_posts', function ($join) {
            $join->on('users.id', '=', 'latest_posts.user_id');
        })->get();

Unions

The query builder also provides a convenient method to "union" two or more queries together. For example, you may create an initial query and use the union method to union it with more queries:

use Illuminate\Support\Facades\DB;

$first = DB::table('users')
            ->whereNull('first_name');

$users = DB::table('users')
            ->whereNull('last_name')
            ->union($first)
            ->get();

In addition to the union method, the query builder provides a unionAll method. Queries that are combined using the unionAll method will not have their duplicate results removed. The unionAll method has the same method signature as the union method.

Basic Where Clauses

Where Clauses

You may use the query builder's where method to add "where" clauses to the query. The most basic call to the where method requires three arguments. The first argument is the name of the column. The second argument is an operator, which can be any of the database's supported operators. The third argument is the value to compare against the column's value.

For example, the following query retrieves users where the value of the votes column is equal to 100 and the value of the age column is greater than 35:

$users = DB::table('users')
                ->where('votes', '=', 100)
                ->where('age', '>', 35)
                ->get();

For convenience, if you want to verify that a column is = to a given value, you may pass the value as the second argument to the where method. Laravel will assume you would like to use the = operator:

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

As previously mentioned, you may use any operator that is supported by your database system:

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

$users = DB::table('users')
                ->where('votes', '<>', 100)
                ->get();

$users = DB::table('users')
                ->where('name', 'like', 'T%')
                ->get();

You may also pass an array of conditions to the where function. Each element of the array should be an array containing the three arguments typically passed to the where method:

$users = DB::table('users')->where([
    ['status', '=', '1'],
    ['subscribed', '<>', '1'],
])->get();

Or Where Clauses

When chaining together calls to the query builder's where method, the "where" clauses will be joined together using the and operator. However, you may use the orWhere method to join a clause to the query using the or operator. The orWhere method accepts the same arguments as the where method:

$users = DB::table('users')
                    ->where('votes', '>', 100)
                    ->orWhere('name', 'John')
                    ->get();

If you need to group an "or" condition within parentheses, you may pass a closure as the first argument to the orWhere method:

$users = DB::table('users')
            ->where('votes', '>', 100)
            ->orWhere(function($query) {
                $query->where('name', 'Abigail')
                      ->where('votes', '>', 50);
            })
            ->get();

The example above will produce the following SQL:

select * from users where votes > 100 or (name = 'Abigail' and votes > 50)

{note} You should always group orWhere calls in order to avoid unexpected behavior when global scopes are applied.

JSON Where Clauses

Laravel also supports querying JSON column types on databases that provide support for JSON column types. Currently, this includes MySQL 5.7+, PostgreSQL, SQL Server 2016, and SQLite 3.9.0 (with the JSON1 extension). To query a JSON column, use the -> operator:

$users = DB::table('users')
                ->where('preferences->dining->meal', 'salad')
                ->get();

You may use whereJsonContains to query JSON arrays. This feature is not supported by the SQLite database:

$users = DB::table('users')
                ->whereJsonContains('options->languages', 'en')
                ->get();

If your application uses the MySQL or PostgreSQL databases, you may pass an array of values to the whereJsonContains method:

$users = DB::table('users')
                ->whereJsonContains('options->languages', ['en', 'de'])
                ->get();

You may use whereJsonLength method to query JSON arrays by their length:

$users = DB::table('users')
                ->whereJsonLength('options->languages', 0)
                ->get();

$users = DB::table('users')
                ->whereJsonLength('options->languages', '>', 1)
                ->get();

Additional Where Clauses

whereBetween / orWhereBetween

The whereBetween method verifies that a column's value is between two values:

$users = DB::table('users')
           ->whereBetween('votes', [1, 100])
           ->get();

whereNotBetween / orWhereNotBetween

The whereNotBetween method verifies that a column's value lies outside of two values:

$users = DB::table('users')
                    ->whereNotBetween('votes', [1, 100])
                    ->get();

whereIn / whereNotIn / orWhereIn / orWhereNotIn

The whereIn method verifies that a given column's value is contained within the given array:

$users = DB::table('users')
                    ->whereIn('id', [1, 2, 3])
                    ->get();

The whereNotIn method verifies that the given column's value is not contained in the given array:

$users = DB::table('users')
                    ->whereNotIn('id', [1, 2, 3])
                    ->get();

{note} If you are adding a large array of integer bindings to your query, the whereIntegerInRaw or whereIntegerNotInRaw methods may be used to greatly reduce your memory usage.

whereNull / whereNotNull / orWhereNull / orWhereNotNull

The whereNull method verifies that the value of the given column is NULL:

$users = DB::table('users')
                ->whereNull('updated_at')
                ->get();

The whereNotNull method verifies that the column's value is not NULL:

$users = DB::table('users')
                ->whereNotNull('updated_at')
                ->get();

whereDate / whereMonth / whereDay / whereYear / whereTime

The whereDate method may be used to compare a column's value against a date:

$users = DB::table('users')
                ->whereDate('created_at', '2016-12-31')
                ->get();

The whereMonth method may be used to compare a column's value against a specific month:

$users = DB::table('users')
                ->whereMonth('created_at', '12')
                ->get();

The whereDay method may be used to compare a column's value against a specific day of the month:

$users = DB::table('users')
                ->whereDay('created_at', '31')
                ->get();

The whereYear method may be used to compare a column's value against a specific year:

$users = DB::table('users')
                ->whereYear('created_at', '2016')
                ->get();

The whereTime method may be used to compare a column's value against a specific time:

$users = DB::table('users')
                ->whereTime('created_at', '=', '11:20:45')
                ->get();

whereColumn / orWhereColumn

The whereColumn method may be used to verify that two columns are equal:

$users = DB::table('users')
                ->whereColumn('first_name', 'last_name')
                ->get();

You may also pass a comparison operator to the whereColumn method:

$users = DB::table('users')
                ->whereColumn('updated_at', '>', 'created_at')
                ->get();

You may also pass an array of column comparisons to the whereColumn method. These conditions will be joined using the and operator:

$users = DB::table('users')
                ->whereColumn([
                    ['first_name', '=', 'last_name'],
                    ['updated_at', '>', 'created_at'],
                ])->get();

Logical Grouping

Sometimes you may need to group several "where" clauses within parentheses in order to achieve your query's desired logical grouping. In fact, you should generally always group calls to the orWhere method in parentheses in order to avoid unexpected query behavior. To accomplish this, you may pass a closure to the where method:

$users = DB::table('users')
           ->where('name', '=', 'John')
           ->where(function ($query) {
               $query->where('votes', '>', 100)
                     ->orWhere('title', '=', 'Admin');
           })
           ->get();

As you can see, passing a closure into the where method instructs the query builder to begin a constraint group. The closure will receive a query builder instance which you can use to set the constraints that should be contained within the parenthesis group. The example above will produce the following SQL:

select * from users where name = 'John' and (votes > 100 or title = 'Admin')

{note} You should always group orWhere calls in order to avoid unexpected behavior when global scopes are applied.

Advanced Where Clauses

Where Exists Clauses

The whereExists method allows you to write "where exists" SQL clauses. The whereExists method accepts a closure which will receive a query builder instance, allowing you to define the query that should be placed inside of the "exists" clause:

$users = DB::table('users')
           ->whereExists(function ($query) {
               $query->select(DB::raw(1))
                     ->from('orders')
                     ->whereColumn('orders.user_id', 'users.id');
           })
           ->get();

The query above will produce the following SQL:

select * from users
where exists (
    select 1
    from orders
    where orders.user_id = users.id
)

Subquery Where Clauses

Sometimes you may need to construct a "where" clause that compares the results of a subquery to a given value. You may accomplish this by passing a closure and a value to the where method. For example, the following query will retrieve all users who have a recent "membership" of a given type;

use App\Models\User;

$users = User::where(function ($query) {
    $query->select('type')
        ->from('membership')
        ->whereColumn('membership.user_id', 'users.id')
        ->orderByDesc('membership.start_date')
        ->limit(1);
}, 'Pro')->get();

Or, you may need to construct a "where" clause that compares a column to the results of a subquery. You may accomplish this by passing a column, operator, and closure to the where method. For example, the following query will retrieve all income records where the amount is less than average;

use App\Models\Income;

$incomes = Income::where('amount', '<', function ($query) {
    $query->selectRaw('avg(i.amount)')->from('incomes as i');
})->get();

Ordering, Grouping, Limit & Offset

Ordering

The `orderBy` Method

The orderBy method allows you to sort the results of the query by a given column. The first argument accepted by the orderBy method should be the column you wish to sort by, while the second argument determines the direction of the sort and may be either asc or desc:

$users = DB::table('users')
                ->orderBy('name', 'desc')
                ->get();

To sort by multiple columns, you may simply invoke orderBy as many times as necessary:

$users = DB::table('users')
                ->orderBy('name', 'desc')
                ->orderBy('email', 'asc')
                ->get();

The `latest` & `oldest` Methods

The latest and oldest methods allow you to easily order results by date. By default, the result will be ordered by the table's created_at column. Or, you may pass the column name that you wish to sort by:

$user = DB::table('users')
                ->latest()
                ->first();

Random Ordering

The inRandomOrder method may be used to sort the query results randomly. For example, you may use this method to fetch a random user:

$randomUser = DB::table('users')
                ->inRandomOrder()
                ->first();

Removing Existing Orderings

The reorder method removes all of the "order by" clauses that have previously been applied to the query:

$query = DB::table('users')->orderBy('name');

$unorderedUsers = $query->reorder()->get();

You may pass a column and direction when calling the reorder method in order to remove all existing "order by "clauses" and apply an entirely new order to the query:

$query = DB::table('users')->orderBy('name');

$usersOrderedByEmail = $query->reorder('email', 'desc')->get();

Grouping

The `groupBy` & `having` Methods

As you might expect, the groupBy and having methods may be used to group the query results. The having method's signature is similar to that of the where method:

$users = DB::table('users')
                ->groupBy('account_id')
                ->having('account_id', '>', 100)
                ->get();

You may pass multiple arguments to the groupBy method to group by multiple columns:

$users = DB::table('users')
                ->groupBy('first_name', 'status')
                ->having('account_id', '>', 100)
                ->get();

To build more advanced having statements, see the havingRaw method.

Limit & Offset

The `skip` & `take` Methods

You may use the skip and take methods to limit the number of results returned from the query or to skip a given number of results in the query:

$users = DB::table('users')->skip(10)->take(5)->get();

Alternatively, you may use the limit and offset methods. These methods are functionally equivalent to the take and skip methods, respectively:

$users = DB::table('users')
                ->offset(10)
                ->limit(5)
                ->get();

Conditional Clauses

Sometimes you may want certain query clauses to apply to a query based on another condition. For instance, you may only want to apply a where statement if a given input value is present on the incoming HTTP request. You may accomplish this using the when method:

$role = $request->input('role');

$users = DB::table('users')
                ->when($role, function ($query, $role) {
                    return $query->where('role_id', $role);
                })
                ->get();

The when method only executes the given closure when the first argument is true. If the first argument is false, the closure will not be executed. So, in the example above, the closure given to the when method will only be invoked if the role field is present on the incoming request and evaluates to true.

You may pass another closure as the third argument to the when method. This closure will only execute if the first argument evaluates as false. To illustrate how this feature may be used, we will use it to configure the default ordering of a query:

$sortByVotes = $request->input('sort_by_votes');

$users = DB::table('users')
                ->when($sortByVotes, function ($query, $sortByVotes) {
                    return $query->orderBy('votes');
                }, function ($query) {
                    return $query->orderBy('name');
                })
                ->get();

Insert Statements

The query builder also provides an insert method that may be used to insert records into the database table. The insert method accepts an array of column names and values:

DB::table('users')->insert([
    'email' => '[email protected]',
    'votes' => 0
]);

You may insert several records at once by passing an array of arrays. Each array represents a record that should be inserted into the table:

DB::table('users')->insert([
    ['email' => '[email protected]', 'votes' => 0],
    ['email' => '[email protected]', 'votes' => 0],
]);

The insertOrIgnore method will ignore duplicate record errors while inserting records into the database:

DB::table('users')->insertOrIgnore([
    ['id' => 1, 'email' => '[email protected]'],
    ['id' => 2, 'email' => '[email protected]'],
]);

Auto-Incrementing IDs

If the table has an auto-incrementing id, use the insertGetId method to insert a record and then retrieve the ID:

$id = DB::table('users')->insertGetId(
    ['email' => '[email protected]', 'votes' => 0]
);

{note} When using PostgreSQL the insertGetId method expects the auto-incrementing column to be named id. If you would like to retrieve the ID from a different "sequence", you may pass the column name as the second parameter to the insertGetId method.

Upserts

The upsert method will insert records that do not exist and update the records that already exist with new values that you may specify. The method's first argument consists of the values to insert or update, while the second argument lists the column(s) that uniquely identify records within the associated table. The method's third and final argument is an array of columns that should be updated if a matching record already exists in the database:

DB::table('flights')->upsert([
    ['departure' => 'Oakland', 'destination' => 'San Diego', 'price' => 99],
    ['departure' => 'Chicago', 'destination' => 'New York', 'price' => 150]
], ['departure', 'destination'], ['price']);

In the example above, Laravel will attempt to insert two records. If a record already exists with the same departure and destination column values, Laravel will update that record's price column.

{note} All databases except SQL Server require the columns in the second argument of the upsert method to have a "primary" or "unique" index.

Update Statements

In addition to inserting records into the database, the query builder can also update existing records using the update method. The update method, like the insert method, accepts an array of column and value pairs indicating the columns to be updated. You may constrain the update query using where clauses:

$affected = DB::table('users')
              ->where('id', 1)
              ->update(['votes' => 1]);

Update Or Insert

Sometimes you may want to update an existing record in the database or create it if no matching record exists. In this scenario, the updateOrInsert method may be used. The updateOrInsert method accepts two arguments: an array of conditions by which to find the record, and an array of column and value pairs indicating the columns to be updated.

The updateOrInsert method will attempt to locate a matching database record using the first argument's column and value pairs. If the record exists, it will be updated with the values in the second argument. If the record can not be found, a new record will be inserted with the merged attributes of both arguments:

DB::table('users')
    ->updateOrInsert(
        ['email' => '[email protected]', 'name' => 'John'],
        ['votes' => '2']
    );

Updating JSON Columns

When updating a JSON column, you should use -> syntax to update the appropriate key in the JSON object. This operation is supported on MySQL 5.7+ and PostgreSQL 9.5+:

$affected = DB::table('users')
              ->where('id', 1)
              ->update(['options->enabled' => true]);

Increment & Decrement

The query builder also provides convenient methods for incrementing or decrementing the value of a given column. Both of these methods accept at least one argument: the column to modify. A second argument may be provided to specify the amount by which the column should be incremented or decremented:

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 during the operation:

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

Delete Statements

The query builder's delete method may be used to delete records from the table. You may constrain delete statements by adding "where" clauses before calling the delete method:

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

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

If you wish to truncate an entire table, which will remove all records from the table and reset the auto-incrementing ID to zero, you may use the truncate method:

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

Table Truncation & PostgreSQL

When truncating a PostgreSQL database, the CASCADE behavior will be applied. This means that all foreign key related records in other tables will be deleted as well.

Pessimistic Locking

The query builder also includes a few functions to help you achieve "pessimistic locking" when executing your select statements. To execute a statement with a "shared lock", you may call the sharedLock method. A shared lock prevents the selected rows from being modified until your transaction is committed:

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

Alternatively, you may use the lockForUpdate method. A "for update" lock prevents the selected records from being modified or from being selected with another shared lock:

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

Debugging

You may use the dd and dump methods while building a query to dump the current query bindings and SQL. The dd method will display the debug information and then stop executing the request. The dump method will display the debug information but allow the request to continue executing:

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

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

Database: Query Builder

Introduction

Running Database Queries

Retrieving All Rows From A Table

Retrieving A Single Row / Column From A Table

Retrieving A List Of Column Values

Chunking Results

Aggregates

Determining If Records Exist

Select Statements

Specifying A Select Clause

Raw Expressions

Raw Methods

selectRaw

whereRaw / orWhereRaw

havingRaw / orHavingRaw

orderByRaw

groupByRaw

Joins

Inner Join Clause

Left Join / Right Join Clause

Cross Join Clause

Advanced Join Clauses

Subquery Joins

Unions

Basic Where Clauses

Where Clauses

Or Where Clauses

JSON Where Clauses

Additional Where Clauses

Logical Grouping

Advanced Where Clauses

Where Exists Clauses

Subquery Where Clauses

Ordering, Grouping, Limit & Offset

Ordering

The orderBy Method

The latest & oldest Methods

Random Ordering

Removing Existing Orderings

Grouping

The groupBy & having Methods

Limit & Offset

The skip & take Methods

Conditional Clauses

Insert Statements

Auto-Incrementing IDs

Upserts

Update Statements

Update Or Insert

Updating JSON Columns

Increment & Decrement

Delete Statements

Table Truncation & PostgreSQL

Pessimistic Locking

Debugging

`selectRaw`

`whereRaw / orWhereRaw`

`havingRaw / orHavingRaw`

`orderByRaw`

`groupByRaw`

The `orderBy` Method

The `latest` & `oldest` Methods

The `groupBy` & `having` Methods

The `skip` & `take` Methods