问个连表的MYSQL查询语句解决方案
问个连表的MYSQL查询语句
假如
表1
id name
1 A
2 B
表2
id money
1 10
1 15
2 20
1 10
如何用左链表的方式，获得如下结果呢
1 A 40
2 B 20
------解决思路----------------------
select a.*, sum(money) as money from 表1 a left join 表2 b on a.id=b.id
1 A 45
2 B 20
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1377
52
MySQL: The Ease of Data Management for Beginners
Apr 09, 2025 am 12:07 AM
MySQL is suitable for beginners because it is simple to install, powerful and easy to manage data. 1. Simple installation and configuration, suitable for a variety of operating systems. 2. Support basic operations such as creating databases and tables, inserting, querying, updating and deleting data. 3. Provide advanced functions such as JOIN operations and subqueries. 4. Performance can be improved through indexing, query optimization and table partitioning. 5. Support backup, recovery and security measures to ensure data security and consistency.
Can I retrieve the database password in Navicat?
Apr 08, 2025 pm 09:51 PM
Navicat itself does not store the database password, and can only retrieve the encrypted password. Solution: 1. Check the password manager; 2. Check Navicat's "Remember Password" function; 3. Reset the database password; 4. Contact the database administrator.
How to create navicat premium
Apr 09, 2025 am 07:09 AM
Create a database using Navicat Premium: Connect to the database server and enter the connection parameters. Right-click on the server and select Create Database. Enter the name of the new database and the specified character set and collation. Connect to the new database and create the table in the Object Browser. Right-click on the table and select Insert Data to insert the data.
How to copy tables in mysql
Apr 08, 2025 pm 07:24 PM
Copying a table in MySQL requires creating new tables, inserting data, setting foreign keys, copying indexes, triggers, stored procedures, and functions. The specific steps include: creating a new table with the same structure. Insert data from the original table into a new table. Set the same foreign key constraint (if the original table has one). Create the same index. Create the same trigger (if the original table has one). Create the same stored procedure or function (if the original table is used).
How to view database password in Navicat for MariaDB?
Apr 08, 2025 pm 09:18 PM
Navicat for MariaDB cannot view the database password directly because the password is stored in encrypted form. To ensure the database security, there are three ways to reset your password: reset your password through Navicat and set a complex password. View the configuration file (not recommended, high risk). Use system command line tools (not recommended, you need to be proficient in command line tools).
How to execute sql in navicat
Apr 08, 2025 pm 11:42 PM
Steps to perform SQL in Navicat: Connect to the database. Create a SQL Editor window. Write SQL queries or scripts. Click the Run button to execute a query or script. View the results (if the query is executed).
How to create a new connection to mysql in navicat
Apr 09, 2025 am 07:21 AM
You can create a new MySQL connection in Navicat by following the steps: Open the application and select New Connection (Ctrl N). Select "MySQL" as the connection type. Enter the hostname/IP address, port, username, and password. (Optional) Configure advanced options. Save the connection and enter the connection name.
MySQL: Simple Concepts for Easy Learning
Apr 10, 2025 am 09:29 AM
MySQL is an open source relational database management system. 1) Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2) Basic operations: INSERT, UPDATE, DELETE and SELECT. 3) Advanced operations: JOIN, subquery and transaction processing. 4) Debugging skills: Check syntax, data type and permissions. 5) Optimization suggestions: Use indexes, avoid SELECT* and use transactions.
