Module is.codion.framework.domain
Package is.codion.framework.domain.entity.condition

Interface CustomCondition

All Superinterfaces:
Condition
public interface CustomCondition extends Condition
A custom Condition based on a ConditionProvider.

Custom conditions are used to create query conditions that cannot be created with the standard Condition, ColumnCondition or ForeignKeyCondition APIs. They enable complex SQL constructs such as subqueries, JOINs, window functions, and database-specific functionality.

A ConditionType is associated with a ConditionProvider, which is responsible for creating the condition string via ConditionProvider.toString(List, List). The ? substitute character is replaced with condition values when the statement is prepared.

Custom conditions provide the flexibility to use any SQL construct while maintaining type safety and parameter binding: 

// Define custom condition types in entity interface
interface Track {
    EntityType TYPE = DOMAIN.entityType("chinook.track");

    // Custom condition with dynamic values
    ConditionType NOT_IN_PLAYLIST = TYPE.conditionType("notInPlaylist");

    // Custom condition without values
    ConditionType EXCLUDED = TYPE.conditionType("excluded");

    // Custom condition with complex SQL
    ConditionType TOP_TRACKS_BY_GENRE = TYPE.conditionType("topTracksByGenre");
}

// Register custom conditions in entity definition
Track.TYPE.define(
        // ... attribute definitions
        )
    .condition(Track.NOT_IN_PLAYLIST, (columns, values) -> {
        // Dynamic subquery with parameter placeholders
        return new StringBuilder()
            .append("trackid NOT IN (")
            .append("    SELECT trackid FROM chinook.playlisttrack")
            .append("    WHERE playlistid IN (")
            .append(String.join(", ", Collections.nCopies(values.size(), "?")))
            .append("))")
            .toString();
    })
    .condition(Track.EXCLUDED, (columns, values) ->
        // Static condition without parameters
        "trackid NOT IN (SELECT trackid FROM chinook.excluded_tracks)")
    .condition(Track.TOP_TRACKS_BY_GENRE, (columns, values) ->
        // Complex condition with window functions
        """
        trackid IN (
            SELECT trackid FROM (
                SELECT trackid,
                       ROW_NUMBER() OVER (PARTITION BY genreid ORDER BY playcount DESC) as rn
                FROM chinook.track_stats
                WHERE genreid = ?
            ) ranked
            WHERE rn <= ?
        )
        """)
    .build();

// Usage examples

// Custom condition with values - tracks not in specific playlists
List<Long> playlistIds = List.of(1L, 5L, 10L);
Condition notInPlaylists = Track.NOT_IN_PLAYLIST.get(Playlist.ID, playlistIds);
List<Entity> availableTracks = connection.select(notInPlaylists);

// Custom condition without values - excluded tracks
Condition excludedCondition = Track.EXCLUDED.get();
List<Entity> nonExcludedTracks = connection.select(excludedCondition);

// Complex custom condition with multiple parameters
Condition topRockTracks = Track.TOP_TRACKS_BY_GENRE.get(
    List.of(Genre.ID, Track.LIMIT),
    List.of(1, 10)); // Genre ID 1, top 10 tracks

// Combine custom conditions with standard conditions
List<Entity> complexQuery = connection.select(and(
    Track.NAME.like("The%"),
    Track.NOT_IN_PLAYLIST.get(Playlist.ID, List.of(1L)),
    Track.UNIT_PRICE.greaterThan(new BigDecimal("0.99"))));

// Use with Select builder for additional control
List<Entity> detailedQuery = connection.select(
    Select.where(Track.TOP_TRACKS_BY_GENRE.get(
            List.of(Genre.ID, Track.LIMIT), List.of(genreId, 5)))
        .attributes(Track.NAME, Track.ALBUM_FK, Track.UNIT_PRICE)
        .orderBy(descending(Track.UNIT_PRICE))
        .build());
See Also:

  • Method Details

    • conditionType

      ConditionType conditionType()
      Returns:
      the condition type