Table of Contents

Xodus-DNQ is a Kotlin library that contains the data definition language and queries for Xodus, a transactional schema-less embedded database. Xodus-DNQ provides the same support for Xodus that ORM frameworks provide for SQL databases. With Xodus-DNQ, you can define your persistent meta-model using Kotlin classes.

JetBrains team tools YouTrack and Hub use Xodus-DNQ for persistent layer definition.

1. Use Xodus-DNQ in Your Project

   1. Using Gradle

   2. Using Maven

2. Persistent Classes

   1. Inheritance

   2. Enumerations

   3. Singletons

3. Persistent Properties

   1. Simple properties

      • Byte

        • xdByteProp — optional byte property

        • xdRequiredByteProp — required byte property

        • xdNullableByteProp — nullable byte property

      • Short

        • xdShortProp — optional short property

        • xdRequiredShortProp — required short property

        • xdNullableShortProp — nullable short property

      • Int

        • xdIntProp — optional integer property

        • xdRequiredIntProp — required integer property

        • xdNullableIntProp — nullable integer property

      • Long

        • xdLongProp — optional long property

        • xdRequiredLongProp — required long property

        • xdNullableLongProp — nullable long property

      • Float

        • xdFloatProp — optional float property

        • xdRequiredFloatProp — required float property

        • xdNullableFloatProp — nullable float property

      • Double

        • xdDoubleProp — optional double property

        • xdRequiredDoubleProp — required double property

        • xdNullableDoubleProp — nullable double property

      • Boolean

        • xdBooleanProp — boolean property

        • xdNullableBooleanProp — nullable boolean property

      • String

        • xdStringProp — optional string property

        • xdRequiredStringProp — required string property

      • Joda DateTime

        • xdDateTimeProp — optional Joda DateTime property

        • xdRequiredDateTimeProp — required Joda DateTime property

      • Blob

        • xdBlobProp — optional blob property

        • xdRequiredBlobProp — required blob property

      • String Blob

        • xdBlobStringProp — optional string blob property

        • xdRequiredBlobStringProp — required string blob property

      • String List

        • xdSetProp — set of comparables property

   2. Simple property constraints

      • Regex

      • Email

      • None of characters

      • Letters only

      • Digits only

      • Digits and letters only

      • URI

      • URL

      • String length

      • Require if

      • Min value

      • Max value

      • Is after

      • Is before

      • Future

      • Past

      • Custom Property Constraints

   3. Links

      • On delete policy

      • Unidirectional assosiations

        • xdLink0_1<XdSource, XdTarget> –– unidirectional [0..1] association

        • xdLink1<XdSource, XdTarget> — unidirectional [1] association

        • xdLink0_N<XdSource, XdTarget> — unidirectional [0..N] association

        • xdLink1_N<XdSource, XdTarget> — unidirectional [1..N] association

      • Bidirectional associations

        • xdLink0_1<XdSource, XdTarget> — bidirectional [0..1] association

        • xdLink1 — bidirectional [1] association

        • xdLink0_N<XdSource, XdTarget> — bidirectional [0..N] association

        • xdLink1_N<XdSource, XdTarget> — bidirectional [1..N] association

      • Aggregations

        • xdChild0_1<XdParent, XdChild> — parent end [0..1] of aggregation association

        • xdChild1<XdParent, XdChild> — parent end [1] of aggregation association

        • xdChildren0_N<XdParent, XdChild> — parent end [0..N] of aggregation association

        • xdChildren1_N<XdParent, XdChild> — parent end [1..N] of aggregation association

        • xdParent<XdChild, XdParent> — child end of aggregation association, when only one parent link is defined for persistent class

        • xdMultiParent<XdChild, XdParent> — child end of aggregation association, when multiple parent links are defined for persistent class

   4. Extension properties

      • Bidirectional links

      • Other properties

   5. isDefined and getSafe

   6. Unique Indices

4. Data Query

   1. Transactions

   2. New entities

   3. XdQuery

      1. Query all entities

      2. Empty query

      3. Convert to Kotlin collections

      4. Query of specified elements

      5. Filter

         • Equals

         • Not Equals

         • Greater than

         • Less than

         • Greater or equal

         • Less or equal

         • Starts with

         • Contains

         • Value in range

         • Set property contains value

         • Set element starts with

         • Not

         • And

         • Or

         • Filter by property of property

      6. Find or Create

      7. Query operations

         • Intersect

         • Union

         • Concatenation

         • Exclusion

      8. Sort

      9. Map

      10. Size

      11. isEmpty, isNotEmpty, any, none

      12. Paging: drop & take

      13. indexOf

      14. Contains

      15. First & single element

      16. Mutable queries

          • Add

          • Remove

          • Add all

          • Remove all

          • Clear

5. Build Meta-Model

6. Sample Application