EXISTS

Creates an EXISTS expression to check for the existence of rows in a subquery.

This function generates a SQL EXISTS (SELECT ...) clause. It evaluates to true if the subquery returns one or more rows, and false otherwise. It is a highly efficient way to check for related data without needing to retrieve the data itself. The subquery can be any valid SELECT statement, often a correlated subquery.

Example

// Find all artists who have at least one album.
// Generates: EXISTS (SELECT "Artist"."Name" FROM "Album" WHERE "Album"."ArtistId" = "Artist"."ArtistId")
select(Artists.name)
    .from(Artists)
    .where {
        EXISTS(
            Album
                 .select(Artists.name)
                 .where { Album.artistId EQ Artists.id }
        )
    }.execute()

Parameters

See also