Exposed Vert.x SQL Client

Exposed on top of Vert.x Reactive SQL Client

Note

Only PostgreSQL with Reactive PostgreSQL Client is currently supported.

Experimental

This library is experimental now. The APIs are subject to change (especially those marked with @ExperimentalEvscApi), the tests are incomplete, and please expect bugs and report them.

Add to your dependencies

The Maven coordinates

"com.huanshankeji:exposed-vertx-sql-client-$module:$libraryVersion"

Important note

As Exposed is a library that has not reached stability yet and often has incompatible changes, you are recommended to stick to the same version of Exposed used by this library. The current version is v0.56.0.

API documentation

See the hosted API documentation for the APIs.

Basic usage guide

Here is a basic usage guide.

Before v0.5.0

Add the PostgreSQL module, which was the only module, to your dependencies with the Gradle build script:

implementation("com.huanshankeji:exposed-vertx-sql-client-postgresql:$libraryVersion")

Since v0.5.0

Add the core module to your dependencies with the Gradle build script:

implementation("com.huanshankeji:exposed-vertx-sql-client-core:$libraryVersion")

And add an RDBMS module, for example, the PostgreSQL module:

implementation("com.huanshankeji:exposed-vertx-sql-client-postgresql:$libraryVersion")

Create a DatabaseClient

Create an EvscConfig as the single source of truth:

val evscConfig = ConnectionConfig.Socket("localhost", user = "user", password = "password", database = "database")
    .toUniversalEvscConfig()

Local alternative with Unix domain socket:

val evscConfig = defaultPostgresqlLocalConnectionConfig(
    user = "user",
    socketConnectionPassword = "password",
    database = "database"
).toPerformantUnixEvscConfig()

Create an Exposed Database with the ConnectionConfig.Socket, which can be shared and reused in multiple Verticles:

val exposedDatabase = evscConfig.exposedConnectionConfig.exposedDatabaseConnectPostgresql()

Create a Vert.x SqlClient with the ConnectionConfig, preferably in a Verticle:

val sqlClient = createPgClient(vertx, evscConfig.vertxSqlClientConnectionConfig)
val pool = createPgPool(vertx, evscConfig.vertxSqlClientConnectionConfig)
val sqlConnection = createPgClient(vertx, evscConfig.vertxSqlClientConnectionConfig)

Create a Database with the provided Vert.x SqlClient and Exposed Database, preferably in a Verticle:

val databaseClient = DatabaseClient(vertxSqlClient, exposedDatabase)

Example table definitions

object Examples : IntIdTable("examples") {
    val name = varchar("name", 64)
}

val tables = arrayOf(Examples)

Use exposedTransaction to execute original blocking Exposed code

For example, to create tables:

databaseClient.exposedTransaction {
    SchemaUtils.create(*tables)
}

If you execute blocking Exposed statements inside Verticles or event loop threads that you shouldn't block, you should use Vert.x Vertx.executeBlocking or Coroutines Dispatchers.IO.

CRUD (DML and DQL) operations with DatabaseClient

Core APIs

With these core APIs, you create and execute Exposed Statements. You don't need to learn many new APIs, and the Statements are more composable and easily editable. For example, you can move a query into an adapted subquery.

// The Exposed `Table` extension functions `insert`, `update`, and `delete` execute eagerly so `insertStatement`, `updateStatement`, `deleteStatement` have to be used.

val insertRowCount = databaseClient.executeUpdate(Examples.insertStatement { it[name] = "A" })
assert(insertRowCount == 1)
// `executeSingleUpdate` function requires that there is only 1 row updated and returns `Unit`.
databaseClient.executeSingleUpdate(Examples.insertStatement { it[name] = "B" })
// `executeSingleOrNoUpdate` requires that there is 0 or 1 row updated and returns `Boolean`.
val isInserted = databaseClient.executeSingleOrNoUpdate(Examples.insertIgnoreStatement { it[name] = "B" })
assert(isInserted)

val updateRowCount =
    databaseClient.executeUpdate(Examples.updateStatement({ Examples.id eq 1 }) { it[name] = "AA" })
assert(updateRowCount == 1)

// The Exposed `Table` extension function `select` doesn't execute eagerly so it can also be used directly.
val exampleName = databaseClient.executeQuery(Examples.selectStatement(Examples.name).where(Examples.id eq 1))
    .single()[Examples.name]

databaseClient.executeSingleUpdate(Examples.deleteWhereStatement { id eq 1 })
databaseClient.executeSingleUpdate(Examples.deleteIgnoreWhereStatement { id eq 2 })

Extension SQL DSL APIs

With the extension SQL DSL APIs, your code becomes more concise, but it might be more difficult when you need to compose statements or edit the code.

Gradle dependency configuration (only needed since v0.5.0):

implementation("com.huanshankeji:exposed-vertx-sql-client-sql-dsl:$libraryVersion")

Example code:

databaseClient.insert(Examples) { it[name] = "A" }
val isInserted = databaseClient.insertIgnore(Examples) { it[name] = "B" }

val updateRowCount = databaseClient.update(Examples, { Examples.id eq 1 }) { it[name] = "AA" }

val exampleName1 =
    databaseClient.select(Examples) { select(Examples.name).where(Examples.id eq 1) }.single()[Examples.name]
val exampleName2 =
    databaseClient.selectSingleColumn(Examples, Examples.name) { where(Examples.id eq 2) }.single()

val examplesExist = databaseClient.selectExpression(exists(Examples.selectAll()))

val deleteRowCount1 = databaseClient.deleteWhere(Examples) { id eq 1 }
assert(deleteRowCount1 == 1)
val deleteRowCount2 = databaseClient.deleteIgnoreWhere(Examples) { id eq 2 }
assert(deleteRowCount2 == 1)

Extension SQL DSL APIs with Exposed GADT mapping

Please read that library's basic usage guide first. Here are examples of this library that correspond to that library's CRUD operations.

Gradle dependency configuration (only needed since v0.5.0):

implementation("com.huanshankeji:exposed-vertx-sql-client-sql-dsl-with-mapper:$libraryVersion")

Example code:

val directorId = 1
val director = Director(directorId, "George Lucas")
databaseClient.insertWithMapper(Directors, director, Mappers.director)

val episodeIFilmDetails = FilmDetails(1, "Star Wars: Episode I – The Phantom Menace", directorId)
// insert without the ID since it's `AUTO_INCREMENT`
databaseClient.insertWithMapper(Films, episodeIFilmDetails, Mappers.filmDetailsWithDirectorId)

val filmId = 2
val episodeIIFilmDetails = FilmDetails(2, "Star Wars: Episode II – Attack of the Clones", directorId)
val filmWithDirectorId = FilmWithDirectorId(filmId, episodeIIFilmDetails)
databaseClient.insertWithMapper(Films, filmWithDirectorId, Mappers.filmWithDirectorId) // insert with the ID

val fullFilms = databaseClient.selectWithMapper(filmsLeftJoinDirectors, Mappers.fullFilm) {
    where(Films.filmId inList listOf(1, 2))
}

About the code

Also see https://github.com/huanshankeji/kotlin-common/tree/main/exposed for some dependency code which serves this library.