Version 0.3

Q: Which dependencies should I set?

A: To use ldbc, you need to set the following dependencies according to your needs.

Connector

To perform database connection processing using ldbc, you need to set one of the following dependencies.

jdbc-connector

If you want to use the traditional connector written in Java, set the following dependencies:

libraryDependencies ++= Seq(
  "io.github.takapi327" %% "jdbc-connector" % "0.3.0-beta11",
  "com.mysql" % "mysql-connector-j" % "8.4.0"
)

ldbc-connector

If you want to use the new connector written in Scala, set the following dependencies:

libraryDependencies ++= Seq(
  "io.github.takapi327" %% "ldbc-connector" % "0.3.0-beta11"
)

ldbc-connector works not only on JVM but also on JS and Native platforms.

To use ldbc with Scala.js or Scala Native, set the dependencies as follows:

libraryDependencies ++= Seq(
  "com.example" %%% "ldbc-connector" % "0.3.0-beta11"
)

Plain DSL

To use the plain DSL, set the following dependencies:

libraryDependencies ++= Seq(
  "io.github.takapi327" %% "ldbc-dsl" % "0.3.0-beta11"
)

Plain DSL is a method to write simple SQL statements as they are. For example, you can execute queries using SQL literals directly.

import ldbc.dsl.*

val plainResult = sql"SELECT name FROM user"
  .query[String]
  .to[List]
  .readOnly(conn)
// plainResult is returned as List[String]

Query Builder

To use the query builder, set the following dependencies:

libraryDependencies ++= Seq(
  "io.github.takapi327" %% "ldbc-query-builder" % "0.3.0-beta11"
)

Query builder is a method to construct queries with type-safe API. In the following example, we define a User model and build a SELECT statement using TableQuery.

import ldbc.dsl.codec.Codec
import ldbc.query.builder.*

case class User(id: Int, name: String, email: String) derives Table
object User:
  given Codec[User] = Codec.derived[User]

val userQuery = TableQuery[User]
  .select(user => user.id *: user.name *: user.email)
  .where(_.email === "alice@example.com")

// userQuery.statement is generated as "SELECT id, name, email FROM user WHERE email = ?"

Schema Definition and Model Mapping

To use schema definition and model mapping, set the following dependencies:

libraryDependencies ++= Seq(
  "io.github.takapi327" %% "ldbc-schema" % "0.3.0-beta11"
)

Schema definition and model mapping enable one-to-one mapping between table definitions and Scala models. Here's an example of defining a User table:

import ldbc.schema.*

case class User(id: Long, name: String, email: String)

class UserTable extends Table[User]("user"):
  def id: Column[Long] = bigint().autoIncrement.primaryKey
  def name: Column[String] = varchar(255)
  def email: Column[String] = varchar(255)
  
  override def * : Column[User] = (id *: name *: email).to[User]

val userQuery = TableQuery[UserTable]
  .select(user => user.id *: user.name *: user.email)
  .where(_.email === "alice@example.com")

// userQuery.statement is generated as "SELECT id, name, email FROM user WHERE email = ?"

References