Article directory Preface Today I encountered the custom variables of the MySQL database at work, which can be used to implement other more complex functions at the rownum level of the Oracle database. 1. Background 2. Scene 3. Preparation work 4. Solution Summarize Foreword Today I encountered the custom variables of the MySQL database at […]
Tag: querying
Spring Data Envers supports the saving and querying of conditional change records
Data auditing is a basic capability of the business system. It requires the system to save all the change records of key data and support the query of the change records. Saving and querying data change records can be easily achieved through spring-data-envers. In some cases, we need to save only the data change records […]
Explore ClickHouse – Using Projection to Speed Up Querying
Outline download file Check files Move files Create table View Files Use client to connect to server Create table Import Data Check data Check the number of data rows Check the disk occupied Inquire Add PROJECTION Query after optimization References Before testing Projection, we need to create a table and import a large amount of […]
How to implement operations such as querying current online users and eliminating logged-in users in the SpringSecurity + SpringSession project
1. Foreword In the previous note “Integrating SpringSession in the SpringBoot project and implementing Session management and event monitoring based on Redis”, we have already practiced integrating SpringSession in the SpringBoot + SpringSecurity project. Here we continue to try to count current online users. The idea is as follows: By counting all current unexpired Session […]
### Error querying database. Cause: java.lang.NumberFormatException: For input string: “e9ca23d68d8
{ “success”: false, “message”: “The operation failed, nested exception is org.apache.ibatis.exceptions.PersistenceException: \r\ ### Error querying database. Cause: java.lang.NumberFormatException: For input string: “e9ca23d68d884d4ebb19d07889727dae”\ r\ ### Cause: java.lang.NumberFormatException: For input string: “e9ca23d68d884d4ebb19d07889727dae””, “code”: 500, “result”: null, “timestamp”: 1694423172882 } 2023-09-11 17:06:12.874 [http-nio-8080-exec-1] ERROR o.jeecg.common.exception.JeecgBootExceptionHandler:79 – nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: java.lang.NumberFormatException: For input […]
Project practice: adding data and querying data in ES
Article directory background Add data in ES Create new index Delete index Query data in ES Query the total amount of data Specific use of projects (actual combat) Introduce dependencies Method 1: Use the configuration class to connect to the corresponding es server Create configuration class Write business logic—-query related chat content based on keywords […]
Optimizing Programming Efficiency Using ChatGPT-4: Efficiently Querying Code Examples and Solutions
Blogger Maotouhu takes you Go to New World.? Blog home page – Maotouhu’s blog “Interview Questions Encyclopedia Column” The article is full of pictures and texts Vivid images Simple and easy to learn! Welcome everyone to step on~ “IDEA Development Cheats Column” Learn the common operations of IDEA and double the work efficiency~ “Proficient in […]
[Error after data source switching: Error querying database. Cause: java.sql.SQLSyntaxErrorException: Table ‘db.tb’]
Background Tool Version: Doesn’t matter Technical framework: Ruoyi management system of springboot Business scenario: The project is a data synchronization system running on Orcl, mysql*2=3 data sources Description of the problem The project was running fine, but after switching the data source, such an error occurred: 14:44:37.219 [http-nio-6666-exec-1] INFO o.a.c.c.C.[.[.[/] – [log,173] – Initializing Spring […]
Idea creates a microservice project and implements the function of querying user orders
Idea creates a microservice project and implements the function of querying user orders In this blog post, I will introduce in detail how to use IDEA software to create a project based on microservice architecture and implement a basic function of querying user orders. We will use Spring Boot as the framework of the project, […]
Axios implements the function of querying city weather
renderings Build the basic page structure html (pages are all rendered by js in the later stage, you can build them first to facilitate css modification styles) <div class=”top-box”> <div class=”title”> <span class=”dateShort”>July 26</span> <span class=”calendar”>Lunar Calendar & amp;nbsp; <span class=”dateLunar”>The ninth day of June</span> </span> </div> <div class=”search-box”> <div class=”location”> <span class=”area”>Hefei City</span> </div> […]