JDBI 3 Assessment Test

A JDBI 3 Assessment Test evaluates individuals on their proficiency in using JDBI 3, a Java-based library designed for database interactions. JDBI simplifies working with relational databases by providing a lightweight, flexible, and fluent API that abstracts away some of the complexities of JDBC (Java Database Connectivity), making it easier for developers to work with SQL in Java applications.

A JDBI 3 Assessment Test evaluates candidates for:

• Familiarity with JDBI 3 architecture, understanding the core components like Handle, SQLObject, and the flexible Fluent API, which allows for easier database interaction compared to raw JDBC.
• Proficiency in managing database connections, including how JDBI handles database sessions using Handle objects, managing transaction lifecycles, and ensuring proper connection handling and closure.
• Skills in using JDBI 3’s SQL Object API, creating Java interfaces and mapping methods directly to SQL queries, simplifying the process of running SQL commands in Java applications.
• Experience in writing SQL queries in JDBI, including basic operations like SELECT, INSERT, UPDATE, and DELETE using both fluent API and SQL Object API for executing queries and mapping results to Java objects.
• Proficiency in managing transactions in JDBI, using declarative transactions (e.g., @Transaction annotation) or programmatically handling transactions with Handle objects to commit or rollback transactions.
• Skills in using JDBI 3's fluent query API, writing queries using the fluent interface for building SQL queries dynamically, mapping results to objects, and streaming query results for performance optimization.
• Understanding of result set mapping in JDBI, using RowMapper and ColumnMapper to map database query results to Java objects, ensuring proper conversion between SQL types and Java types.
• Proficiency in handling complex queries, writing and executing joins, subqueries, and aggregate functions in SQL using JDBI and efficiently mapping the results to Java models.
• Skills in object mapping using @Bind annotations, mapping method parameters to SQL query placeholders with annotations like @Bind, @BindBean, @BindList, and others to safely inject values into queries and prevent SQL injection attacks.
• Knowledge of JDBI 3 plugins, using plugins like PostgresPlugin, SqlObjectPlugin, and KotlinPlugin to extend JDBI’s capabilities and provide additional support for working with specific database systems or languages.
• Proficiency in working with JDBI's SqlUpdate and SqlQuery, executing both update/insert statements and select queries, and understanding the differences in how these are handled in terms of result processing.
• Understanding of data validation and error handling, using JDBI’s mechanisms to handle database constraints, exceptions, and errors, ensuring that transactions are rolled back in the event of failure.
• Skills in using Jdbi.onDemand(), creating on-demand SQL objects to simplify the use of database connections by lazily initializing SQL objects and automatically managing database handles.
• Experience in customizing JDBI behavior, writing custom RowMapper or ResultSetMapper classes to customize how database rows are mapped to complex Java objects.
• Proficiency in working with JDBI and Java 8 features, using lambda expressions, streams, and the Optional type in combination with JDBI’s API to write more concise and functional code.
• Skills in managing batch operations, using Batch or Script classes to execute multiple statements efficiently, and handling large-scale inserts, updates, or deletes in a performant manner.
• Proficiency in integrating JDBI with popular frameworks, such as Spring or Dropwizard, to manage database interactions in enterprise applications.
• Knowledge of handling stored procedures in JDBI, understanding how to call and handle the results of stored procedures and functions in relational databases.
• Proficiency in handling large datasets and streaming, leveraging JDBI’s ability to stream large result sets efficiently using Java Streams and processing data in chunks without overwhelming memory.
• Experience with JDBI test utilities, writing unit tests for database interactions, using in-memory databases like H2 for testing purposes, and ensuring that SQL queries and result mapping work as expected.
• Proficiency in data migration and versioning, using JDBI in combination with tools like Flyway or Liquibase to manage database schema changes and data migrations in applications.
• Skills in configuring JDBI for performance optimization, tuning query performance, minimizing overhead, and managing connection pooling with JDBI for better scalability and efficiency in high-load environments.

Overall, a JDBI 3 Assessment Test evaluates candidates' abilities to interact with relational databases in a simplified yet powerful way using JDBI 3.

It assesses both technical skills (such as query execution, result mapping, and transaction management) and practical expertise (such as handling complex SQL queries, managing batch operations, and integrating JDBI with frameworks), ensuring candidates can effectively develop and maintain Java applications with efficient database interactions.

This evaluation is essential for identifying individuals who can leverage JDBI 3’s capabilities to build robust, maintainable, and performant database-driven applications in Java.