Learn how to query a table using just the Partition Key and how to enhance those queries by including the Range Key to filter results within a partition.
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Baeldung Editor
Michal Aibin
Michal Aibin is a Faculty at British Columbia Institute of Technology and Visiting Associate Professor at Northeastern University with over 10 years experience in software development industry. He received his doctorate degree in Informatics in 2017 and since then published more than 50 research papers. His main research interests are optimization and modeling of computer networks, and adaptive algorithms and machine learning for geospatial analysis/remote sensing. Personally, he enjoys horseback riding and playing music.
Here's what I've reviewed (so far):
Baeldung on Java
- All
- Java (89)
- Core Java (72)
- Testing (69)
- Spring Boot (60)
- Java String (54)
- Spring (53)
- Persistence (37)
- Algorithms (34)
- Java Numbers (33)
- Spring Security (29)
- Java IO (29)
- Java Collections (27)
- Spring Data (26)
- DevOps (26)
- NoSQL (25)
- REST (24)
- Data (24)
- Java Dates (23)
- Spring MVC (22)
- JVM (22)
- Java List (21)
- Java Map (20)
- Security (19)
- Jakarta EE (19)
- JPA (19)
- Maven (18)
- Jackson (18)
- Java Array (16)
- JSON (16)
- Java Concurrency (15)
- HTTP Client-Side (15)
- Spring Cloud (13)
- Java Streams (13)
- Reactive (12)
- Cloud (11)
- Architecture (11)
- Spring Web (10)
- Groovy (10)
- Spring Persistence (9)
- Networking (9)
- Logging (8)
- IDE (7)
- Gradle (7)
- XML (6)
- Web Services (6)
- Spring WebFlux (4)
- Artificial Intelligence (4)
- Java Web (2)
- Docker (2)
Validate Map Using Spring Validator
Filed under Spring
Learn how to validate a Map using Spring’s Validator interface.
Transcribing Audio Files With OpenAI in Spring AI
Filed under Artificial Intelligence, Spring Boot
Explore transcribing audio files with OpenAI in Spring AI.
How to Fix Exception: Cannot Load Driver Class: com.mysql.jdbc.driver in Spring Boot
Filed under Spring Boot, Spring Persistence
Explore the cause of the Cannot load driver class: com.mysql.jdbc.Driver exception in Spring Boot and see how to fix it by updating the driver class name and project dependencies.
Generate a Valid Expression From a String of Numbers to Get Target Number
Filed under Algorithms, Java Numbers, Java String
Learn how to generate valid expressions by inserting binary operators between digits to match a target value.
How to Run a Java Program in the Background
Filed under Java
Learn how to run a Java application as a background process, explore how to keep it running after closing the terminal session, and monitor it using logs.
Get Number of Files in a Directory and Its Subdirectories in Java
Filed under Java IO
Explore two approaches to counting files in a directory and its subdirectories in Java.
What Is an API in Java?
Filed under Core Java
Learn what an API is in the context of Java, understand various types of APIs, and see an example implementation.
Copy Specific Fields by Using BeanUtils.copyProperties in Spring
Filed under Spring
Explore various approaches to copying specific fields using BeanUtils.copyProperties in Java.
Baeldung on Linux
- All
- Administration (117)
- Scripting (70)
- Processes (70)
- Filesystems (38)
- Security (37)
- Files (31)
- Networking (28)
- File Editing (27)
- User Administration (23)
- Installation (21)
- Network Configuration (18)
- Web (17)
- File Viewing (17)
- File Searching (12)
- Package Management (10)
- File Permissions (10)
- Boot Process (10)
- File Compression (9)
- Text Processing (8)
- Network Monitoring (7)
- File Conversion (7)
- File Transfer (6)
- Building (3)
- Service Management (2)
- Search (2)
- Docker (1)
Add Newline at the End of curl Response Body
Filed under File Transfer
Explore practical ways to automatically append a newline to curl responses, ensuring consistent shell behavior.
How to Pipe Data to cURL POST Requests
Learn how to pipe data to cURL POST requests.
Intel and AMD Microcode and Properly Updating Microcode in Linux
Filed under Installation, Processes
Learn about processor microcode and see how to check and update it in Linux for two major processor manufacturers.
How to Disable Fast (Quick) Boot When BIOS and UEFI Are Inaccessible
Filed under Boot Process
Learn about a firmware option that enables faster booting for some operating systems but might prevent us from getting into the BIOS or UEFI setup.
How To Automatically Connect to a VPN in Linux
Filed under Network Configuration
Explore two ways to connect to a virtual private network in Linux automatically.
SMB mount Security Modes and Fixing mount error(13): Permission denied in Linux
Filed under Filesystems
Explore the mount command, its security modes related to the SMB protocol, an unexpected error that mismatches can produce, and the implications of different settings.
What Are the rcuos or rcuob Processes Seen in the Output of top?
Filed under Administration, Processes
Learn about the kernel read-copy-update (RCU) mechanism, its historical implementation, and current guiding principles.
How to Determine if a Specific Module Is Loaded in the Linux Kernel
Filed under Boot Process, Installation
Learn to check whether the kernel has loaded a given module or not.
Download a Large File From Google Drive Using the CLI
Filed under File Transfer
Explore effective methods for downloading large files from Google Drive using command-line tools.
Baeldung on Scala
- All
- Scala Collections (4)
- Testing (2)
- Scala Strings (2)
- Scala Syntax (1)
- Scala Numbers (1)
- Scala Concurrency (1)
- Scala Basics (1)
- Libraries (1)
- Akka (1)
CSV Files in Scala
Filed under Libraries, Scala Numbers, Scala Strings
Learn how to read and write CSV files with Scala.
Different Ways To Iterate Over Collections in Scala
Filed under Scala Collections
Explore how to iterate over collections in Scala using foreach and for comprehension.
How to Check If Code Compiles in ScalaTest
Filed under Testing
Learn how to test whether a Scala snippet compiles using Matchers or Assertions.
Understanding the Differences: reduceLeft, reduceRight, foldLeft, foldRight, scanLeft, and scanRight in Scala
Filed under Scala Collections
Learn about six powerful functions of Scala language for aggregating the elements of a collection.
Get a Subarray in Scala
Filed under Scala Collections
Learn how to obtain subarrays in Scala, exploring two primary methods: the slice() function and the combination of drop() and take().
Introduction to Parallelism and Parallel Collections
Filed under Scala Concurrency
Explore some theoretical concepts of parallel computing applied with Scala.
Testing Akka Actors
Filed under Akka
Explore how we can test Actors to ensure that they behave as expected.
Usages of Underscore (_) in Scala
Filed under Scala Syntax
Explore different ways to use the Scala underscore.
String Interpolation in Scala
Filed under Scala Strings
Explore different ways of using string interpolation in Scala.
Baeldung on Computer Science
- All
- Networking (143)
- Machine Learning (122)
- Security (87)
- Algorithms (86)
- Programming (83)
- Math and Logic (77)
- OS (67)
- Deep Learning (61)
- Software Architecture (37)
- Data Structures (36)
- Trees (35)
- Artificial Intelligence (35)
- Computer Vision (34)
- Sorting (26)
- Graphs (22)
- Latex (18)
- Core Concepts (15)
- Graph Traversal (14)
- Data Science (14)
- Searching (13)
- Path Finding (11)
- Concurrency (7)
- Research (6)
- Web (5)
- Graph Theory (3)
- Methodology (1)
What Is a Monotonic Stack?
Filed under Data Structures
Learn to use a monotonic stack and implement it effectively, significantly enhancing your ability to solve complex problems efficiently.
What Is Duck Typing?
Filed under Programming
Explore the programming concept of duck typing, defining it from different standpoints.
Different Text Summarization Techniques Using Langchain
Filed under Deep Learning
Explore LangChain’s stuffing, map-reducing, refining, and custom techniques, which all depend on the user’s specific requirements, document features, and overall performance expectations.
Select Rows in Pandas Dataframes Based on a Column
Filed under Data Science
Learn how to filter a Pandas dataframe based on a single column.
How to Create Custom GPT Models
Filed under Deep Learning
Learn how to build custom GPT models tailored to help businesses, researchers, and developers address specific needs.
Changing the Ticks on the x or y Axis in Matplotlib
Filed under Data Science
Explore four ways to control ticks and their labels in Matplotlib plots: manual methods, locators, formatters, and log scales for clearer, more informative plots.
How to Change the Size of a Figure in Matplotlib?
Filed under Data Science
Explore four ways to customize a Matplotlib figure’s size in width, height, and pixels.
Multiple Plots in the Same Figure in Matplolib
Filed under Data Science
Explore two ways to create figures with multiple subplots in Matplotlib: with a regular layout as rectangular grid and the mosaic layout where some subplots may span multiple rows or columns.
Convert IP Address Range to CIDR Notation
Filed under Networking
Learn how to convert an IPv4 address range into the Classless Inter-Domain Routing notation.
Baeldung on Kotlin
- All
- Kotlin Collections (7)
- Kotlin Basics (6)
- Testing (3)
- Spring (3)
- Libraries (3)
- Kotlin-Java Interop (3)
- Kotlin Server-Side (3)
- Kotlin (3)
- Kotlin Classes and Objects (2)
- Kotlin Arrays (2)
- HTTP Client-Side (2)
- Algorithms (2)
- Persistence (1)
- Kotlin Web (1)
- Kotlin Strings (1)
- Kotlin IO (1)
- Kotlin Functions (1)
- Functional Programming (1)
Download PDF Files with Retrofit and Coroutines
Filed under Kotlin
Explore an efficient approach to downloading PDF files using Retrofit and the support of Kotlin Coroutines.
Functional HTTP Endpoints with Spring MVC/WebFlux and Kotlin
Filed under Functional Programming, HTTP Client-Side, Spring
Explore the functional API for Spring WebFlux and Spring WebMVC in Kotlin.
A Look at the Ktor Client
Filed under HTTP Client-Side, Kotlin Web
Explore various solutions offered by the Ktor Client.
A Guide to RSocket with Kotlin
Filed under Kotlin Server-Side, Libraries
Learn how to use RSocket with Kotlin.
Remove Elements From a List While Iterating in Kotlin
Filed under Kotlin Basics
Learn how to remove elements from a list when iterating over it.
Print Lists Content Separated by Comma
Filed under Kotlin Collections
Explore different techniques to print a List’s elements separated by a comma in Kotlin.
Kotlin actual Keyword
Filed under Kotlin-Java Interop
Explore two Kotlin keywords: expect and actual.
Using Java Reflection with Kotlin Companion Objects
Filed under Kotlin-Java Interop
Learn how to access Kotlin companion objects via Java Reflection API.
The Difference Between Int and Integer in Kotlin
Filed under Kotlin Basics
Explore the differences between Int and Integer in Kotlin.
Baeldung on Ops
- All
- Docker (51)
- Git (30)
- Kubernetes (26)
- Jenkins (14)
- DevOps (6)
- Logging (3)
- Cloud (3)
- Deployment Tools (2)
- DevOps Concepts (1)
Guide to Getting the Commit Message in GitHub Actions
Learn how to get the commit message in GitHub actions.
Guide to Getting Commit SHA in GitHub Actions
Learn how to get the commit SHA in GitHub actions.
Run Gunicorn Server in Docker
Filed under Docker
Learn how to run a Gunicorn server in Docker.
Guide to Getting Commit SHA in GitHub Actions
Learn how to get the commit SHA in GitHub actions.
Ubuntu Docker Container: Fixing “bash: ping: command not found” Error
Filed under Docker
Learn how to address the absence of the ping command in a Ubuntu Docker image.
How to Push Changes to a Repository from a GitLab CI Pipeline
Filed under Git
Learn how to push code changes to a GitLab repository.
Execute a Bash Command Conditionally Based on Docker Container Existence
Filed under Docker
Learn multiple ways to check if a Docker container exists before attempting to create it in a Bash script.
Performing Django Database Migrations With Docker-Compose
Filed under Docker
Learn how to effectively handle database migrations using Docker Compose and PostgreSQL in a dockerized environment.
Deploy create-react-app on Nginx
Filed under Cloud
Learn how to deploy a React application on an Nginx server, optimizing it for performance and security.
Baeldung on SQL
- All
- SQL Queries (11)
- SQL Joins (7)
- Database Concepts (6)
- SQL Tables (3)
- SQL Operators (2)
- SQL Functions (2)
- SQL Basics (2)
- Database Access (2)
- Databases (1)
- DDL (1)
Convert Month Number to Month Name Function in SQL
Filed under SQL Functions
Explore different approaches to get the month names using numbers in SQL.
Lateral Join vs. Subquery: What’s the Difference
Filed under SQL Joins, SQL Queries
Explore the differences between lateral joins and subqueries.
Differences Between JSON and JSONB Data Types in PostgreSQL
Filed under SQL Basics
Explore the differences between JSON and JSONB in PostgreSQL, especially with respect to their storage mechanisms and performance characteristics.
Counting Instances of Character in SQL Column
Filed under SQL Queries
Learn how to count a character in a column in MySQL, PostgreSQL, and SQL Server.
Determine the Database Version in SQL
Filed under Databases
Tutorial on finding database server versions for relational databases.
Give All Permissions to a User in SQL
Filed under Database Access
Learn how to grant all necessary permissions to a user in PostgreSQL, MySQL, and SQL Server.
How to Sum Two Columns in an SQL Query?
Filed under SQL Queries
Learn about summing two columns using column expressions, aggregation, and window functions.
Recursive Queries in MySQL
Filed under SQL Queries
Learn how to write a recursive query in MySQL using a recursive common table expression.
How to Reset Auto Increment in MySQL
Filed under Database Concepts
Learn about resetting the auto-increment sequence in MySQL.