First, selects
Retrieving all rows in a table
Copy Code code as follows:
$users = db::table (' users ')->get ();
foreach ($users as $user)
{
Var_dump ($user->name);
}
Retrieving a single row from a table
Copy Code code as follows:
$user = db::table (' users ')->where (' name ', ' John ')->first ();
Var_dump ($user->name);
retrieving rows for a single column
Copy Code code as follows:
$name = db::table (' users ')->where (' name ', ' John ')->pluck (' name ');
retrieves a list of column values
Copy Code code as follows:
$roles = db::table (' roles ')->lists (' title ');
This method returns the role of an array caption. You can also specify a custom key column to return an array of
Copy Code code as follows:
$roles = db::table (' roles ')->lists (' title ', ' name ');
Specify a SELECT clause
Copy Code code as follows:
$users = db::table (' users ')->select (' name ', ' email ')->get ();
$users = db::table (' users ')->distinct ()->get ();
$users = db::table (' users ')->select (' name as user_name ')->get ();
The SELECT clause is added to an existing query $query = db::table (' users ')->select (' name ');
Copy Code code as follows:
$users = $query->addselect (' Age ')->get ();
where
Copy Code code as follows:
$users = db::table (' users ')->where (' votes ', ' > ', M)->get ();
OR
Copy Code code as follows:
$users = db::table (' users ')->where (' votes ', ' > ')->orwhere (' name ', ' John ')->get ();
Where Between
Copy Code code as follows:
$users = db::table (' users ')->wherebetween (' votes ', array (1))->get ();
Where not Between
Copy Code code as follows:
$users = db::table (' users ')->wherenotbetween (' votes ', array (1))->get ();
Where in with the An Array
Copy Code code as follows:
$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
Copy Code code as follows:
$users = db::table (' users ')->wherenull (' Updated_at ')->get ();
Order BY, Group by, and has
Copy Code code as follows:
$users = db::table (' users ')->orderby (' name ', ' desc ')->groupby (' Count ')->having (' Count ', ' > ')-> Get ();
Offset & Limit
Copy Code code as follows:
$users = db::table (' users ')->skip->take (5)->get ();
Second, the connection
Joins
The query Builder can also be used to write connection statements. Take a look at the following example:
Basic Join Statement
Copy Code code as follows:
Db::table (' users ')
->join (' Contacts ', ' users.id ', ' = ', ' contacts.user_id ')
->join (' orders ', ' users.id ', ' = ', ' orders.user_id ')
->select (' users.id ', ' contacts.phone ', ' Orders.price ')
->get ();
Left JOIN-Connect statement
Copy Code code as follows:
Db::table (' users ')
->leftjoin (' posts ', ' users.id ', ' = ', ' posts.user_id ')
->get ();
Db::table (' users ')
->join (' Contacts ', function ($join)
{
$join->on (' users.id ', ' = ', ' contacts.user_id ')->oron (...);
})
->get ();
Db::table (' users ')
->join (' Contacts ', function ($join)
{
$join->on (' users.id ', ' = ', ' contacts.user_id ')
->where (' contacts.user_id ', ' > ', 5);
})
->get ();
Third, grouped
Sometimes, you might want to create a more advanced where clause, such as "exist" or a nested parameter grouping. Laravel Query Builder can handle these:
Copy Code code as follows:
Db::table (' users ')
->where (' name ', ' = ', ' John ')
->orwhere (function ($query)
{
$query->where (' votes ', ' > ', 100)
->where (' title ', ' <> ', ' Admin ');
})
->get ();
The query above will produce the following SQL:
Copy Code code as follows:
SELECT * from users where name = ' John ' or (Votes > and title
<> ' Admin ')
Exists statements
Db::table (' users ')
->whereexists (function ($query)
{
$query->select (Db::raw (1))
->from (' orders ')
->whereraw (' orders.user_id = Users.id ');
})
->get ();
The query above will produce the following SQL:
Copy Code code as follows:
SELECT * FROM Userswhere exists (
Select 1 from orders where orders.user_id = Users.id
)
Iv. Aggregation
The Query Builder also provides a variety of aggregation methods, such as statistics, Max, Min,avg, and totals.
Using Aggregate Methods
Copy Code code as follows:
$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 might want to use a query of the original expression. These expressions will inject the query string, so be careful not to create any SQL injection points! Create an original expression, you can use Db:rawmethod:
Using A Raw Expression
Copy Code code as follows:
$users = db::table (' users ')
->select (Db::raw (' count (*) as User_count, status '))
->where (' status ', ' <> ', 1)
->groupby (' status ')
->get ();
Increments or decrements the value of a column
Copy Code code as follows:
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:
Copy Code code as follows:
Db::table (' users ')->increment (' votes ', 1, Array (' name ' => ' John '));
Inserts
Insert a record into a table
Copy Code code as follows:
Db::table (' users ')->insert (
Array (' email ' => ' john@example.com ', ' votes ' => 0)
);
Automatically increase the ID of the record inserted into the table
If the table has an automatically incremented ID field, use Insertgetid to insert a record and retrieve the ID:
Copy Code code as follows:
$id = db::table (' users ')->insertgetid (
Array (' email ' => ' john@example.com ', ' votes ' => 0)
);
Note: When using the PostgreSQL Insertgetid method, the self-added column is named "id".
Multiple records inserted into a table
Copy Code code as follows:
Db::table (' users ')->insert array (
Array (' email ' => ' taylor@example.com ', ' votes ' => 0),
Array (' email ' => ' dayle@example.com ', ' votes ' => 0),
));
Four, Updates
Update records in one table
Copy Code code as follows:
Db::table (' users ')
->where (' id ', 1)
->update (Array (' votes ' => 1));
Five, deletes
Delete a record from a table
Copy Code code as follows:
Db::table (' users ')->where (' votes ', ' < ', m)->delete ();
Delete all records in a table
Copy Code code as follows:
Db::table (' users ')->delete ();
Delete a table
Copy Code code as follows:
Db::table (' users ')->truncate ();
VI. Unions
The Query Builder also provides a quick way to "federate" two queries:
Copy Code code as follows:
$first = db::table (' users ')->wherenull (' first_name ');
$users =
Db::table (' users ')->wherenull (' last_name ')->union ($first)->get ();
The UnionAll method can also be signed with the same method.
Pessimistic locking
The query Builder includes some "pessimistic locking" features to help you make your SELECT statement. To run the SELECT statement shared lock, you can use the Sharedlock method to query:
Copy Code code as follows:
Db::table (' users ')->where (' votes ', ' > ',
->sharedlock ()->get ();
Update "Lock" in a SELECT statement, you can query using the Lockforupdate method:
Copy Code code as follows:
Db::table (' users ')->where (' votes ', ' > ')->lockforupdate ()->get ();
VII. Caching queries
You can easily cache the results of a query using the mnemonic method:
Copy Code code as follows:
$users = db::table (' users ')->remember->get ();
In this case, the result of the query will be cached for 10 minutes. When the query results cache, the database is not run, and the result specifies your application from the default cache load driver. If you are using a driver that supports caching, you can also add a label to cache:
Copy Code code as follows:
$users = db::table (' users ')->cachetags (Array (' People ', ' authors ')->remember ()->get ();
