# API version may be set only once exception
**URL:** https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221
**Category:** Using FoundationDB
**Tags:** bindings
**Created:** [July 2, 2020, 2:19am UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221 "2020-07-02T02:19:30Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@omidb](https://forums.foundationdb.org/u/omidb)
#### Post date: [July 2, 2020, 2:19am UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221/1 "2020-07-02T02:19:30Z")
I’m trying to run the a sample code in Scala. I could run it one time and after that, I get the following error:
```auto
import com.apple.foundationdb.Database;
import com.apple.foundationdb.FDB;
import com.apple.foundationdb.tuple.Tuple;
object FoundationDBTest extends App {
println(s"is API version selected? ${FDB.isAPIVersionSelected()}")
val fdb =
if (!FDB.isAPIVersionSelected()) FDB.selectAPIVersion(620)
else FDB.instance()
def main(args: Array[String]) {
try {
val db = fdb.open()
// Run an operation on the database
db.run(tr => {
tr.set(Tuple.from("hello").pack(), Tuple.from("world").pack())
null
})
// Get the value of 'hello' from the database
val hello = db.run(tr => {
val result = tr.get(Tuple.from("hello").pack()).join()
Tuple.fromBytes(result).getString(0)
})
println("Hello " + hello)
} catch {
case _ => println("error")
}
}
}
```
and exception:
```
[info] running FoundationDBTest
is API version selected? false
[error] (run-main-f) com.apple.foundationdb.FDBException: API version may be set only once
[error] com.apple.foundationdb.FDBException: API version may be set only once
[error] at com.apple.foundationdb.FDB.Select_API_version(Native Method)
[error] at com.apple.foundationdb.FDB.selectAPIVersion(FDB.java:199)
[error] at com.apple.foundationdb.FDB.selectAPIVersion(FDB.java:180)
[error] at FoundationDBTest$.delayedEndpoint$FoundationDBTest$1(FoundationDBTest.scala:8)
[error] at FoundationDBTest$delayedInit$body.apply(FoundationDBTest.scala:5)
[error] at scala.Function0.apply$mcV$sp(Function0.scala:39)
[error] at scala.Function0.apply$mcV$sp$(Function0.scala:39)
[error] at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:17)
[error] at scala.App.$anonfun$main$1$adapted(App.scala:80)
[error] at scala.collection.immutable.List.foreach(List.scala:392)
[error] at scala.App.main(App.scala:80)
[error] at scala.App.main$(App.scala:78)
[error] at FoundationDBTest$.main(FoundationDBTest.scala:5)
[error] at FoundationDBTest.main(FoundationDBTest.scala)
[error] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[error] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[error] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[error] at java.base/java.lang.reflect.Method.invoke(Method.java:567)
[error] stack trace is suppressed; run last Compile / bgRun for the full output
[error] Nonzero exit code: 1
[error] (Compile / run) Nonzero exit code: 1
[error] Total time: 2 s, completed Jul 1, 2020, 10:16:03 PM
```
---
### Author:  [@gaurav](https://forums.foundationdb.org/u/gaurav)
#### Post date: [July 2, 2020, 7:51am UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221/2 "2020-07-02T07:51:07Z")
You should reuse the `db` object across multiple transactions.
---
### Author:  [@omidb](https://forums.foundationdb.org/u/omidb)
#### Post date: [July 2, 2020, 11:05am UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221/3 "2020-07-02T11:05:01Z")
I am using almost the exact code from the documentation just converted to Scala. Here is the code I’m using: [https://apple.github.io/foundationdb/javadoc/index.html](https://apple.github.io/foundationdb/javadoc/index.html)
Which object should get reused? FDB? Exactly where?
---
### Author:  [@gaurav](https://forums.foundationdb.org/u/gaurav)
#### Post date: [July 2, 2020, 11:36am UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221/4 "2020-07-02T11:36:33Z")
> [@omidb](#):
>
> ```auto
> val fdb =
> if (!FDB.isAPIVersionSelected()) FDB.selectAPIVersion(620)
> else FDB.instance()
>
> def main(args: Array[String]) {
>
> try {
> val db = fdb.open()
>
> ```
I believe you should reuse all objects upto this point. Use the existing `val db` object for running transactions.
---
### Author:  [@omidb](https://forums.foundationdb.org/u/omidb)
#### Post date: [July 2, 2020, 11:52am UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221/5 "2020-07-02T11:52:04Z")
The exception message is about FDB selectAPIVersion. The second time running the code on JVM, I get the error message that API version should not get set more than one time.
---
### Author:  [@omidb](https://forums.foundationdb.org/u/omidb)
#### Post date: [July 2, 2020, 1:17pm UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221/6 "2020-07-02T13:17:22Z")
I figured out how to solve it. Because FoundationDB has native binding and I was running the code in SBT (build tool for Scala) I had to make sure `fork` is enabled in the build file.
---
### Author:  [@josephg](https://forums.foundationdb.org/u/josephg)
#### Post date: [July 5, 2020, 11:35am UTC](https://forums.foundationdb.org/t/api-version-may-be-set-only-once-exception/2221/7 "2020-07-05T11:35:18Z")
I solved this issue in the nodejs bindings by making it so subsequent calls to setAPIVersion which use the same version number do nothing.
The scala bindings should probably do the same thing.