Explore the inequality operator in Laravel database

Laravel is a popular open source PHP framework with rich features and components that is widely used in the development of web applications. One of the important components is the database, which can easily interact with various databases. In Laravel, the inequality operator (!=) is a commonly used comparison operator used to check if a value is equal to another value. In this article, we will explore the inequality operator in Laravel database.

1. Overview

The inequality operator (!=) is an operator used to compare whether two values ​​are equal. In Laravel's database application, we can use the inequality operator to check if the value of a database field is different from another value. The inequality operator can be used on a variety of data types, including numbers, strings, dates, and Boolean values.

For example, we can use the following code to query all users who are not 18 years old:

$users = DB::table('users')->where('age', '!=', 18)->get();

This will query all users whose age is not 18 years old in the users table, and will The results are saved in the $users variable.

2. Examples of using the inequality operator

Let’s look at some practical examples of how to use the inequality operator in Laravel.

2.1 Using the inequality operator in the where clause

In Laravel's query builder, we can use the where method to build a query statement. The following example demonstrates how to use the inequality operator:

$users = DB::table('users')->where('age', '!=', 18)->get();

This query will return all users whose age is not 18 years old.

2.2 Use the inequality operator in the orWhere clause

We can also use the inequality operator in the orWhere clause to find records that meet any one of a set of conditions. For example, the following code will query for all users who are not administrators or secretaries:

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

This query will return all users who are not administrators or secretaries.

2.3 Use the inequality operator in the whereIn clause

The whereIn clause is used to check whether the field value is included in the specified value list. We can use the notIn method to check if the field value is not included in the value list. The following example will query for all users who are not in the specified city list:

$users = DB::table('users')
    ->whereNotIn('city', ['New York', 'California'])
    ->get();

This query will return all users who are not in New York or California.

3. Summary

In Laravel, the inequality operator is a commonly used comparison operator used to check whether a field value is not equal to another value. We can use the inequality operator in methods such as where, orWhere, whereIn and whereNotIn to build complex query statements. Learning and mastering the inequality operator in Laravel database will help us make better use of the powerful database functions provided by the Laravel framework.

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