Detailed introduction about hasMany-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

Detailed introduction about hasMany

零下一度

Jun 11, 2017 pm 05:53 PM

hasOne and hasMany are Yii2's unique functions for multi-table related queries. It is recommended to use them when using multi-table related queries. This article mainly introduces the detailed usage of hasOne, hasMany and many-to-many related queries in Yii2. Friends who need it can refer to the preface. hasOne and hasMany are Yii2's unique functions for multi-table related queries. Multi-table related queries are usually used. It is recommended to use them when querying. Why? Because the results of related queries in this way will retain Yii2's own header sorting function, as well as the id storage value of the input in CheckboxColumn. As for whether there are other benefits, everyone needs to dig out. The author has discovered these two so far. A common benefit. There are no other related queries, such as yiidbQuery query or native SQL statement query. When the query is displayed in the list, the header of the table is black. Yii2's hasOne and hasMany multi-table related queries, whether it is a document or an article, can actually easily find the reference master. But why did the author write this article? The idea is actually very simple, because

1. Detailed introduction about hasOne

Detailed introduction about hasMany

##Introduction: hasOne and hasMany are unique to Yii2 Functions used for multi-table related queries. It is recommended to use them when using multi-table related queries. This article mainly introduces the detailed usage of hasOne, hasMany and many-to-many related queries in Yii2. Friends who need it can refer to the preface. hasOne and hasMany are Yii2's unique functions for multi-table related queries. Multi-table related queries are usually used. It is recommended to use them when querying. Why? Because the results of related queries in this way will retain Yii2's own header sorting function,...

2. hasOne, hasMany and many-to-many relationships in Yii2 Query usage example (picture)

Detailed introduction about hasMany

##Introduction: hasOne and hasMany are unique to Yii2 for multiple tables Related query functions, it is recommended to use them when using multi-table related queries. This article mainly introduces the detailed usage of hasOne, hasMany and many-to-many related queries in Yii2. Friends in need can refer to

yii2 Update multiple related tables Field

Introduction: There are two tables account and user. The account table has fields mobile and bind. The user table also has mobile and bind fields. The account class and user The class uses hasMany to associate through uid. When the account table mobile.bind is updated, the user table association is automatically updated. Please tell me, automatic update...

[Related Q&A recommendations]:

laravel ORM problem

php - yii2 Association table updates multiple fields

php - Yii Related tables with optimized queries to avoid N+1 query questions

sql - Why do ORM frameworks (Hibernate of JAVA and Sequelize of Node.js) have to have a relationship to perform join queries? ?

php - laravel eloquent How to build a reply to comment

The above is the detailed content of Detailed introduction about hasMany. For more information, please follow other related articles on the PHP Chinese website!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

How to calculate the total number of elements in a PHP multidimensional array?May 15, 2025 pm 09:00 PM

Calculating the total number of elements in a PHP multidimensional array can be done using recursive or iterative methods. 1. The recursive method counts by traversing the array and recursively processing nested arrays. 2. The iterative method uses the stack to simulate recursion to avoid depth problems. 3. The array_walk_recursive function can also be implemented, but it requires manual counting.

What are the characteristics of do-while loops in PHP?May 15, 2025 pm 08:57 PM

In PHP, the characteristic of a do-while loop is to ensure that the loop body is executed at least once, and then decide whether to continue the loop based on the conditions. 1) It executes the loop body before conditional checking, suitable for scenarios where operations need to be performed at least once, such as user input verification and menu systems. 2) However, the syntax of the do-while loop can cause confusion among newbies and may add unnecessary performance overhead.

How to hash strings in PHP?May 15, 2025 pm 08:54 PM

Efficient hashing strings in PHP can use the following methods: 1. Use the md5 function for fast hashing, but is not suitable for password storage. 2. Use the sha256 function to improve security. 3. Use the password_hash function to process passwords to provide the highest security and convenience.

How to implement array sliding window in PHP?May 15, 2025 pm 08:51 PM

Implementing an array sliding window in PHP can be done by functions slideWindow and slideWindowAverage. 1. Use the slideWindow function to split an array into a fixed-size subarray. 2. Use the slideWindowAverage function to calculate the average value in each window. 3. For real-time data streams, asynchronous processing and outlier detection can be used using ReactPHP.

How to use the __clone method in PHP?May 15, 2025 pm 08:48 PM

The __clone method in PHP is used to perform custom operations when object cloning. When cloning an object using the clone keyword, if the object has a __clone method, the method will be automatically called, allowing customized processing during the cloning process, such as resetting the reference type attribute to ensure the independence of the cloned object.

How to use goto statements in PHP?May 15, 2025 pm 08:45 PM

In PHP, goto statements are used to unconditionally jump to specific tags in the program. 1) It can simplify the processing of complex nested loops or conditional statements, but 2) Using goto may make the code difficult to understand and maintain, and 3) It is recommended to give priority to the use of structured control statements. Overall, goto should be used with caution and best practices are followed to ensure the readability and maintainability of the code.

How to implement data statistics in PHP?May 15, 2025 pm 08:42 PM

In PHP, data statistics can be achieved by using built-in functions, custom functions, and third-party libraries. 1) Use built-in functions such as array_sum() and count() to perform basic statistics. 2) Write custom functions to calculate complex statistics such as medians. 3) Use the PHP-ML library to perform advanced statistical analysis. Through these methods, data statistics can be performed efficiently.

How to use anonymous functions in PHP?May 15, 2025 pm 08:39 PM

Yes, anonymous functions in PHP refer to functions without names. They can be passed as parameters to other functions and as return values of functions, making the code more flexible and efficient. When using anonymous functions, you need to pay attention to scope and performance issues.

See all articles