Extracting Data From Azure SQL database using Akka.io - scala

Question

Currently, I am able to create a session using intelliJ:
//sqlserver is the name of application.conf {}
val databaseConfig = DatabaseConfig.forConfig[JdbcProfile]("sqlserver")
implicit val session = SlickSession.forConfig(databaseConfig)
this is the config:
sqlserver = {
profile = "slick.jdbc.SQLServerProfile$"
db {
driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver"
host = <myHostName> e.g. myresource.database.windows.net
port = <myPortNumber> e.g 1433
databaseName = <myDatabaseName>
url = <jdbc:sqlserver:myHostName:port;database=myDatabase>
user = <user>
password = <password>
connectionTimeout = "30 seconds"
}
}
Some of the methods suggested are:
// The example domain
case class User(id: Int, name: String)
val users = (1 to 42).map(i => User(i, s"Name$i"))
// This import enables the use of the Slick sql"...",
// sqlu"...", and sqlt"..." String interpolators.
// See "http://slick.lightbend.com/doc/3.2.1/sql.html#string-interpolation"
import session.profile.api._
// Stream the users into the database as insert statements
val done: Future[Done] =
Source(users)
.via(
// add an optional first argument to specify the parallelism factor (Int)
Slick.flow(user => sqlu"INSERT INTO ALPAKKA_SLICK_SCALADSL_TEST_USERS VALUES(${user.id}, ${user.name})")
)
.log("nr-of-updated-rows")
.runWith(Sink.ignore)
I couldn't find any examples of methods for me to extract any data with SQL commands from Akka.io. The closest one is at this link:
[Akka.io Slink JDBC][1]
At this point, there are no errors for the connection, but i'm still lacking of the methods to access and downloading from Azure SQL databases with Query methods.
This one looks like it is creating it's own Vector List.
case class User(id: Int, name: String)
val users = (1 to 42).map(i => User(i, s"Name$i"))
Results: Vector(User(1,Name1), User(2,Name2), ....)
Is there a way where I can extract my data from Azure SQL server?
[1]: https://doc.akka.io/docs/alpakka/current/slick.html

Answer 1

If you want to get data from SQL Server into an Akka Stream, you need a Source, not a Sink (which is for writing from Akka into the database).
Because Alpakka defers JDBC integration to the Slick library, it's perhaps worth reading up on that library.
From the documentation, you'll want something like:
import slick.jdbc.GetResult
import session.profile.api._
case class User(id: Int, name: String)
// Define how to transform result rows (each row being a PositionedResult)
// into Users. See https://scala-slick.org/doc/3.3.2/sql.html
implicit val getUserFromResult = GetResult(r => User(r.nextInt, r.nextString))
val gotAllUsers: Future[Done] =
Slick.source(sql"SELECT id, name FROM table".as[User])
.log("user")
.runWith(Sink.ignore)
// Wait for the query to complete before exiting, only useful for this example.
Await.result(gotAllUsers, Duration.Inf)