Laravel Framework Database curd operation, coherent operation summary __ Database

One, selects retrieve all rows in the table

$users = db::table (' users ')->get ();
foreach ($users as $user)
{
var_dump ($user->name);
}

retrieving a single row from a table

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

Retrieving a field value for a single column

$name = db::table (' users ')->where (' name ', ' John ')->pluck (' name ');

retrieves a field value for a single column (laravel>5.0)

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

retrieves a list of column values

$roles = db::table (' roles ')->lists (' title ');

retrieves a list of column values (laravel>5.0)

$roles = db::table (' roles ')->pluck (' title ');

This method returns the role of an array caption. You can also specify a custom key column to return an array of

$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 ();

The 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 ', ' > ', M)->get ();

OR

$users = db::table (' users ')->where (' votes ', ' > ')->orwhere (' name ', ' John ')->get ();

Where Between

$users = db::table (' users ')->wherebetween (' votes ', array (1))->get ();

Where not Between

$users = db::table (' users ')->wherenotbetween (' votes ', array (1))->get ();

Where in with the 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 query condition is NULL

$users = db::table (' users ')->wherenull (' Updated_at ')->get ();

Order by, Group by, and has

$users = db::table (' users ')->orderby (' name ', ' desc ')->groupby (' Count ')->having (' Count ', ' > ')-> Get ();

Offset & Limit

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

Like condition fuzzy query

$users = db::table (' users ')->where (' name ', ' like ', '% '. $name. ') % ')->get ();

second, the connection joins query Builder can also be used to write connection statements.

Look at the following example: basic join Statement Base Connection 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 Connection 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 ();

third, grouped

Sometimes, you might want to create a more advanced where clause, such as "exist" or a nested parameter grouping. laravel Query Builder (laravel Query Builder) can handle these:

Db::table (' users ')
->where (' name ', ' = ', ' John ')
->orwhere (function ($query)
{
$query- >where (' votes ', ' > ')
->where (' title ', ' <> ', ' Admin ');
}
->get ();

the query above will produce the following SQL:

SELECT * from users where name = ' John ' or (votes > and title
<> ' Admin ')
Exists statements
D B::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
)

The aggregate Query Builder also provides a variety of aggregation methods, such as statistics, Max, Min,avg, and totals. Using Aggregate Methods (using aggregation method)

$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 may sometimes need 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 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 ();

increments or decrements 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 a record into a table

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:

$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

Db::table (' users ')->insert (Array (
' email ' => ' taylor@example.com ', ' votes ' => 0),
Array (' Email ' => ' dayle@example.com ', ' votes ' => 0))
;

v. Updates update records in a table

Db::table (' users ')
->where (' id ', 1)
->update (Array (' votes ' => 1));

Vi. Deletes delete records in a table

Db::table (' users ')->where (' votes ', ' < ', m)->delete ();

Delete all records in a table

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

Delete a table

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

vii. The Unions Query Builder also provides a quick way to "federate" two queries:

$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 (pessimistic lock)

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:

Db::table (' users ')->where (' votes ', ' > ')->sharedlock ()->get ();

Update "Lock" in a SELECT statement, you can query using the Lockforupdate method:

Db::table (' users ')->where (' votes ', ' > ')->lockforupdate ()->get ();

Viii. Caching Queries

You can easily cache the results of a query using the mnemonic method:

$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:

$users = db::table (' users ')->cachetags (Array (' People ', ' authors ')->remember ()->get ();