Kysely is a TypeScript SQL query builder that provides a type-safe interface for constructing and executing database queries. It functions as a database layer that ensures schema compliance and prevents runtime errors by using a fluent interface and a programmable way to build complex SQL statements.
The project features a type-safe database layer capable of inferring return types and aliases from SQL selections and joins. It also includes a SQL migration manager to track and apply schema changes across different environments to keep database versions synchronized.
The toolkit covers relational database integration through dynamic query construction and the execution of raw SQL statements. It allows for the creation of parameterized SQL snippets and the ability to reference tables and columns dynamically at runtime.