Scaladbc

Update

Scala DBC2 seems to be in a state of orphanage.

There are newer attempts in this space, such as, scala-query and orbroker, which are likely to give you better mileage.

Scala Data base connector version 2

The DBC library comes packaged along with Scala (Look under $(scala-distribution)/src/).

There's a newer, unreleased, version called DBC2 available here. But it appears to be unmaintained.

The download available as an attachment to this page is a simple fix to the above, to get it in a working shape.

Compilation

The source can be built with SBT

Demo

See the file demo/demo.scala inside the package. It shows how to create, update and query a Derby database (requires Apache Derby to be in the class path).

Acknowledgement

The original authors did all the work. I just fixed some typos and stuff.

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Why connection was closed?

rakuto (guest) 1232889830|%e %b %Y, %H:%M %Z|agohover

Try to CRUD operation using dbc2 package, but couldn't execute queries because scala.dbc2.exception.ClosedException was thrown.
How do I execute some queries?

import scala.dbc2.exception._

import java.sql._
import java.net.URI
import scala.dbc2.Database
import scala.dbc2.ShortSyntax._
import scala.dbc2.statement.AnyValueDef._
import scala.dbc2.statement.Relation
import scala.dbc2.statement.Status
import scala.dbc2.vendor.MySQL

object Demo extends Application {
    def printResults(res: dbc2.result.Relation) {
        for(val i <- res) {
            for(val f <- i.fields) {
                print("\t" + f.content.sqlString) 
            } 
            println()
        } 
    }

    val vendor:scala.dbc2.Vendor = scala.dbc2.vendor.MySQL(new URI("jdbc:mysql://localhost:3306/scala_test"), "mysql", "mysql")
    var db = new Database(vendor)

    // crate test DB
    try {
        var stmt = create table 'people columns('id integer primary key, 'name character varying(255))
        db.executeStatement(stmt.parse)
        println("Success")
    } catch {
        case e:Exception => println("table `people` already created")
    }

    // truncate a table
    var stmt = delete from 'people
    db.executeStatement(stmt.parse)

    // insert data
    val people = List((1, "Martin Odersky"), (2, "Guid van Rossam"))
    people.foreach {
        person => 
            var stmt2 = insert into 'people columns('id, 'name) values((person._1, person._2))
            // XXX: Failed because scala.dbc2.exception.ClosedException exception was thrown
            db.executeStatement(stmt2.parse)
    }

    var stmt3 = select(*) from('people)
    printResults(db.executeStatement(stmt3.parse))
}

Best regards.

Re: Why connection was closed?

hrj 1232965490|%e %b %Y, %H:%M %Z|agohover

Hi rakuto,

I am not well versed with the scala DBC2 package. I just brought it to a state where it compiled. The run-time behaviour is a little difficult to understand.

Looking at the source code, it seems like a call to Vendor.closeConnection happens after every statement is executed. It's not clear to me how it is re-opened again.

I advise you ask on the scala mailing list for support.

Cheers,
HRJ

Re: Why connection was closed?

Sailaja (guest) 1249538775|%e %b %Y, %H:%M %Z|agohover

Hi,
I am also facing the same problem . I have searched for this on google no result. Is any solution for this problem….

Thanks in advance '
Sailaja.

Re: Why connection was closed?

hrj 1249620919|%e %b %Y, %H:%M %Z|agohover

I have added an update to the top of the page.

Please check out the other projects llisted there which are more likely to be stable.

Help to compile DBC2

Santi (guest) 1252322395|%e %b %Y, %H:%M %Z|agohover

Hi HRJ,
I am new to this word, scala and dbc.
I need bdc2 but dont know how to build with SBT package.
¿can you show me to configuration for do it?
Thanks very much

What about dbc2/dbc3 in Scala 2.8.
Will be included?
Where is the api doc for these libraries?
Thank very much

How to Extract table values

mansur 1255253761|%e %b %Y, %H:%M %Z|agohover

I am using scala lift . Also i using mysql to retrive the table value .

My doubt is ,

My query is —>val stmt4 = select ('id,'name) from('category) where 'name <>("'Contact'") and 'name <>("'Faq'")
printResults(db.executeStatement(stmt4.parse))

I want to display a id and name value .

def printResults(res: dbc2.result.Relation) {
for(val i <- res) {
for(val f <- i.fields) {
print("\t"+f.content.nativeValue)
}
println()
}
}

This code , f.content.nativeValue display value. i wnat how to extract id and name value.
send reply mail moc.liamg|5002ilarusnam#moc.liamg|5002ilarusnam

last edited on 1255253822|%e %b %Y, %H:%M %Z|agohover by mansur + show more