Regarding the problem that one-to-many children have multiple pieces of data, the database can check it but the code can only get one piece. - Code World

Regarding the problem that one-to-many children have multiple pieces of data, the database can check it but the code can only get one piece.

Language 2023-10-05 05:50:30 views: null

This kind of problem is usually caused by careless copying and pasting by programmers. The problem lies in the mapper mapping.

Just remove this, because the ID is unique, so even if there are multiple ones, he can only get one.

Guess you like

Origin blog.csdn.net/qq_50158494/article/details/121559283

Regarding the problem that one-to-many children have multiple pieces of data, the database can check it but the code can only get one piece.

Regarding the problem that one-to-many children have multiple pieces of data, the database can check it but the code can only get one piece.

Regarding the problem that one-to-many children have multiple pieces of data, the database can check it but the code can only get one piece.

The reason why only one piece of data can be found in Mybatis one-to-many query

When mybatis collection nests query statements, only one possible problem is queried for multiple pieces of data.

Regarding the problem that @Scheduled scheduled tasks can only execute one task at a time

The three paradigms of database design can be understood with only one article (because I have a short story)

Request to get inputStream can only get one solution

Use EasyExcel to import the database content into the Excel table, and only 500 pieces of data can be imported at most

To whom life is very fair, no one can have only once

Sequelize one-to-one, one-to-many, many-to-many, you can't learn to cut me

Record a problem. When using element-table, only one input box is displayed when rendering multiple pieces of data, and other data is rendered based on the input value of the input box.

There are multiple pieces of the same data in mysql except for ID, and only one of them is taken (user login)

There are multiple pieces of the same data in mysql except for ID, and only one of them is taken (user login)

There are multiple pieces of the same data in mysql except for ID, and only one of them is taken (user login)

Can epilepsy have children?

Can epilepsy have children?

Problem solving in C language: Xiao Ming has five new books and wants to lend them to children A, B, and C. If each person can only borrow one book at a time, how many different ways can they borrow it?

A way to save space when springboot uploads the same file (only one file is kept in the local storage path, but there can be multiple records in the database)

Two pieces of code coexist in one file, and a part of it can be selectively compiled during compilation. How many ways are there? How to achieve? (Pen questions)

There are so many low-code platforms, it may be the only one that can be used to find a job

It turns out that as long as you change the table structure of the data source, you can simplify the complex one-to-many mail merge!

Leaflet Tutorial 016: Use Polygon to draw nested polygons, one array with multiple pieces of data (sample code)

Successfully solved the problem that VScode can only open one file at a time, that is, only one editing window can be opened.

[Common code 12] window.open to open multiple new windows is disabled solution, window.open(url) download multiple files can only download one solution

mysql uses one sql to delete multiple pieces of data

Error: Rule can only have one resource source (provided resource and test + include + exclude)

JAVA design pattern 1: Singleton mode, ensuring that each class can only have one instance

How many pieces of data can be stored in list in java

Can only one of using and or be selected in leftjoin?

Recommended

Ranking

#2019110700005

What materials and procedures are required for patent transfer

What is the blockchain Ethereum triplet state root transaction root receipt root

Front-end study notes 04 --- About the insertion of html pictures and videos

Documents required for the filing of WeChat Mini Programs in special industries, the filing process of WeChat Mini Programs in special industries, how to file WeChat Mini Programs in special industries

2017 Qingdao-site tournament I The Squared Mosquito Coil

[BZOJ3165][HEOI2013]Segment (line segment tree without marking)

Kettle series: KettleEasyExpand, an open source Kettle universal plugin by Ma Jinju

The latest tutorial on making framework for iOS

DAX Section 6: Statistical Functions

Daily

More

2024-05-14(9)

2024-05-13(8)

2024-05-12(28)

2024-05-11(32)

2024-05-10(34)

2024-05-09(32)

2024-05-08(18)

2024-05-07(34)

2024-05-06(6)

2024-05-05(0)