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On this page

  * Overview
  * Java: Stream-based result methods
  * Java: Better array/list field support
  * DuckDB: List types in Appender

On this page

  * Overview
  * Java: Stream-based result methods
  * Java: Better array/list field support
  * DuckDB: List types in Appender

SQG v0.10.0: Java Streams & List Type Support

Mar 5, 2026
 
Uwe Maurer

SQG is a type-safe SQL code generator -- you write .sql files with
annotated queries, and it generates strongly-typed database access
code for TypeScript and Java by introspecting your queries against
real database engines at build time.

Here's what's new in v0.10.0.

Java: Stream-based result methods

Section titled "Java: Stream-based result methods"

Generated Java code now includes methods that return Stream<T> in
addition to List<T>. This gives you lazy evaluation, easier
composition with the standard library, and avoids materializing large
result sets into memory when you don't need to.

try (Stream<User> users = queries.getAllUsersStream()) {
    users.forEach(user -> process(user));
}

The stream holds a reference to the underlying ResultSet, so it needs
to be closed after use -- hence the try-with-resources.

Java: Better array/list field support

Section titled "Java: Better array/list field support"

Array columns like TEXT[] or INTEGER[] are now handled correctly in
generated Java code. Previously these types could produce incorrect
mappings -- they now resolve to proper List<String>, List<Integer>,
etc.

DuckDB: List types in Appender

Section titled "DuckDB: List types in Appender"

The DuckDB appender now supports list/array column types. If your
table has a column like tags VARCHAR[], the generated appender method
accepts the corresponding list type and writes it correctly using
DuckDB's bulk insert API.

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Upgrade with npm install -g @sqg/[email protected] or update your
project's dependency. Full source on GitHub. Try it out in the
playground.

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