Easy-Query: A Strongly-Typed Java ORM with LINQ-Style Queries and Zero Dependencies

Background

After several years of Java development, the author sought a .NET-like ORM that allows writing intuitive SQL through strong-typed syntax for 90% of business scenarios. MyBatis-Plus initially seemed promising but proved incomplete: most scenarios lack expression or strong-typed support, causing features like soft-delete to break with joins, and handwritten SQL makes configurations unintelligent — effectively reducing it to a SQL helper. MyBatis-Plus-Join fares worse, requiring constant trial-and-error to "stitch" desired statements. Consequently, the author built Easy-Query, porting the mature .NET ORM ecosystem's chainable expression semantics to Java.

Query Capabilities

All examples use a fluent queryable(Entity.class) entry point with lambda expressions referencing entity getters (e.g., Topic::getId) for compile-time safety.

Basic Queries

First or null: .where(o -> o.eq(Topic::getId, "123")).firstOrNull() generates

SELECT `id`,`stars`,`title`,`create_time` FROM `t_topic` WHERE `id` = ? LIMIT 1

.

Single or null (asserts ≤1 row): Same WHERE but without LIMIT; throws if multiple rows match.

List: .toList() returns all matching rows.

Custom columns: .select(o -> o.column(Topic::getId).column(Topic::getTitle)) projects only id, title.

Pagination: .toPageResult(1, 20) runs a COUNT query then the paged SELECT ... LIMIT 20.

Advanced Queries

Subquery as derived table: A Queryable can be select -ed into an anonymous table and then leftJoin -ed, producing a nested SELECT ... FROM (subquery) t1 LEFT JOIN ....

EXISTS subquery:

.where(o -> o.exists(subQueryable.where(q -> q.eq(o, BlogEntity::getId, Topic::getId))))

correlates the outer Topic alias t inside the inner BlogEntity query, yielding

WHERE EXISTS (SELECT 1 FROM `t_blog` t1 WHERE t1.`deleted` = ? AND t1.`id` = ? AND t1.`id` = t.`id`)

.

Multi-table JOIN:

.leftJoin(BlogEntity.class, (t, t1) -> t.eq(t1, Topic::getId, BlogEntity::getId))

automatically appends the joined table's soft-delete filter ( t1.`deleted` = ?) to the ON clause.

Streaming large results: .toStreamResult() returns a JdbcStreamResult iterable for memory-efficient processing; the example iterates 100+ rows with assertions.

Custom VO mapping: Multiple joins (two- and three-parameter lambdas) with .select(QueryVO.class, (t, t1, t2) -> ...) maps columns across tables to a DTO using columnAs(Source::getField, VO::getTarget) and then() to switch context.

Dynamic form query: .whereObject(queryRequest) inspects a request DTO's non-null fields (String → LIKE, List → IN, LocalDateTime → <=) and builds the WHERE clause automatically.

Primitive results: .select(String.class, o -> o.column(Topic::getId)).toList() returns List<String>.

Grouping & aggregation:

.groupBy(o -> o.column(Topic::getId)).select(DTO.class, o -> o.columnAs(Topic::getId, DTO::getId).columnCount(Topic::getId, DTO::getIdCount))

produces

SELECT t.`id` AS `id`, COUNT(t.`id`) AS `idCount` ... GROUP BY t.`id`

; groupKeysAs shortcut aliases group keys by index.

Native SQL fragment:

.where(o -> o.sqlNativeSegment("regexp_like({0},{1})", it -> it.expression(H2BookTest::getPrice).value("^Ste(v|ph)en$")))

embeds dialect-specific functions while keeping parameter binding.

Database Function Columns

Easy-Query supports transparent column-level SQL functions (e.g., Base64 encode/decode, PostGIS geography types) so the entity holds plain Java types while the generated SQL applies the conversion. Documentation: https://xuejm.gitee.io/easy-query-doc/guide/adv/column-sql-func-auto.html

High-Performance Encryption with LIKE Support

Column-level encryption/decryption that still permits LIKE queries on encrypted data, with optional emoji-safe modes. Documentation: https://xuejm.gitee.io/easy-query-doc/guide/adv/column-encryption.html

Additional Features

Data change tracking & differential updates

Atomic field updates

Sharding (horizontal partitioning)

Zero third-party dependencies

Dual Java/Kotlin support

Repositories

GitHub: https://github.com/xuejmnet/easy-query

Gitee: https://gitee.com/xuejm/easy-query