How to use ORM query builder in Laravel framework

How to use the ORM query builder in the Laravel framework

As a popular PHP development framework, the Laravel framework provides many convenient database operation functions. Among them, the ORM query builder is a commonly used database query method in Laravel. Through the ORM query builder, we can query the database in an object-oriented manner, avoiding directly writing SQL statements, which improves the readability and maintainability of the code. This article will introduce some commonly used ORM query builder methods and give actual code examples.

1. Query all records

Using the ORM query builder, we can use the table method to specify the data table to query, and use The get method gets all records. For example, assuming we have a data table named users, we can query all records using the following code:

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

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

The above code will return all records in the users table , and print each user's name through a foreach loop.

2. Query records of specified fields

If we only need to query certain fields in the data table, we can use the select method to specify the query field. For example, the following code queries the name and email fields in the users table:

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

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

3. Queries a single record

If we only need to query one record in the data table, we can use the first method. For example, the following code queries the first record in the users table:

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

echo $user->name;
echo $user->email;

Note that when using the first method, if the query result is empty, ## will be returned #null value.

Query records that meet the conditions

Using the ORM query builder, we can use the

where method to add query conditions and only query records that meet the conditions. . For example, the following code queries the records with the role field value in the users table:

$users = DB::table('users')
            ->where('role', 'admin')
            ->get();

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

The above code will return users

All records whose

role field value is admin in the table. Sort query results

5. If you need to sort the query results according to a certain field, you can use the
orderBy

method. For example, the following code queries the records in the

users table that are sorted in ascending order by the name field:

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

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

The above code will return the records sorted in ascending order by the name

field user records.

Paging query results

6. When querying a large amount of data, we usually need to perform paging processing. Laravel's ORM query builder also provides convenient pagination functionality. For example, the following code queries the records in the
users

table, and paging them according to 10 records per page:

$users = DB::table('users')->paginate(10);

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

echo $users->links();

The above code will query all records in the users table, And displayed in paging according to 10 items per page.

linksThe method will output paginated links. Through the above code examples, we can see that it is very convenient to use the ORM query builder in the Laravel framework. It provides a variety of query methods to meet various query needs. By using the ORM query builder, we can write concise and readable database query code. At the same time, the ORM query builder also provides more database operation methods, such as updating data, deleting data, etc. I hope this article has been helpful to you in using the ORM query builder in the Laravel framework.

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