export might be able to solve that, not sure
Task (as quoted in the snippet above) along with DAO/Repository. Now that we spoke of H2 (only for testing), question I am getting is - is it a good idea to test with H2 when the production is going to be something else. Kind of beginner with slick - not sure if this advisable. If so - any directions ? Thanks
SchemaGenerator is needed. SchemeGenerator requires Database and collection Table[Model]. There is also this sticky import statement import slick.jdbc.PostgresProfile.api._ which I want to keep it min files as possible. Given these I am looking for design these classes.
The question is why you want to keep that import statement in as min files as possible? If it's because your project is the barebones for building other projects, then you can always store somewhere in a global object the profile you want to use. Something like
object DatabaseGlobals {
def profile = slick.jdbc.PostgresProfile
}and then you can import that instead, via my.package.DatabaseGlobals.profile.api._.
If the reason is for mocks in tests, then I think you can put your table definitions inside a trait which requires an abstract jdbc profile, and feed that profile by extending the trait (I think that works)
WrappingQuery (like forUpdate) implicit protected class AddNoWait[E, U, C[_]](val q: Query[E, U, C]) {
def nowait: Query[E, U, C] = {
???
new WrappingQuery[E, U, C](q.toNode, q.shaped)
}
}
The question is why you want to keep that import statement in as min files as possible? If it's because your project is the barebones for building other projects, then you can always store somewhere in a global object the profile you want to use. Something like
object DatabaseGlobals { def profile = slick.jdbc.PostgresProfile }and then you can import that instead, via
my.package.DatabaseGlobals.profile.api._.
If the reason is for mocks in tests, then I think you can put your table definitions inside a trait which requires an abstract jdbc profile, and feed that profile by extending the trait (I think that works)
@sherpal - Intention is to use an in memory database for testing.
Here is something that I am trying to do with Slick.
- I have a column in a table which is NOT a primary key but I want to have a global ordering on it. Initial thinking was to have it an
AUTO_INCcolumn - On insert things are fine with the
AUTO_INCdoing its part in assigning an incremented value automatically - Now my use case demands that when a row gets updated I want to change the value of that column to the (max-value of the column + 1), something like
update table set global_offset = select max(global_offset)+1 from table
Besides the fact that this might have performance implications, the underlying sequence of the AUTO_INC column does not get updated. Hence this same value can be inserted in another row as well through an insert statement.
Any help how I can do this with Slick ? Thanks.
Can someone tell me if this config looks correct for mysql using Slick 3.3.1 on Scala 2.12?
nc {
mysql {
profile = "slick.jdbc.MySQLProfile$"
dataSourceClass = "slick.jdbc.DatabaseUrlDataSource"
properties = {
driver = "com.mysql.cj.jdbc.Driver"
databaseName = "analytics_cache_schema"
serverName = "localhost"
portNumber = 3306
user = "analytics_cache"
password = "qwe90qwe"
characterEncoding = "utf8"
useUnicode = true
}
numThreads = 10
keepAliveConnection = true
}
}I initialize with Database.forConfig("nc.mysql") but getting this error: java.lang.ClassNotFoundException: slick.jdbc.DatabaseUrlDataSource
It only happens in EMR 6.0.0 in Spark 2.4.4, and not in my tests run by sbt
If I inspect my jar with I can see slick/jdbc/DatabaseUrlDataSource.class is included
I have a simple insert that looks like:
records += Record(c1, c2, c3)I'd like to change it to make that insert conditional. I don't want to proceed with the insert if a record exists where the all the columns match but c3 is null.
I'd like to have Slick generate the following:
insert into mytable (c1, c2, c3) values ('one', 'two', 'three')
where not exists (select 1 from mytable where c1 = 'one' and c2 = 'two' and c3 is null);
5 replies
Hi everyone, does anyone have experience using Slick with the Squants library? I am trying to add two colums of Rep[Length] together. The thing I'm running into seems like an implicit string conversion is being applied, messing things up. The first value (bow) is lifted and read as Rep[Length], the second (stern) however has anyOptionLift(primitiveShape(stringColumnType)) implicit added to it. Both bow and stern in the for comprehension are read as Rep[Length] but the yield uses the any2stringadd implicit causing a String expected error.
val length: Rep[Option[Length]] = for {
bow <- nearbyVessel.distanceToBow
stern <- nearbyVessel.distanceToStern
} yield bow + sternAny suggestions on how I can solve this by using explicit extension methods or writing my own are greatly appreciated, cheers.
I have a situation where I have a complex query, for parts of which I already have lifted slick queries, the rest is (still) plain sql at the moment.
In the end I want to use the query's results for an update which, as far as I can tell, is not currently possible with slick without loading it from the db into the memory of my service and sending it back to the db again, correct?
But I would like to use lifted slick as much as possible.
Baased on this , the two solutions I see are:
- running the complex query using slick and storing the results in a temporary table to then do the update in plain sql
- get the sql statement generated from my lifted slick query as a string and use it in a plain sql update statement (via string concatenation)
The first issue I encountered while trying out the second option is that the generated sql contains generated column names like x1, x2 etc. I managed to workaround that by wrapping the query in some plain sql that renames the columns based on their position (e.g. using a with-clause/cte) but all this gives me the impression that this is a bad practice. I would be grateful for some thoughts on this.
java.lang.ClassNotFoundException: slick.jdbc.DatabaseUrlDataSourcewhen I run
Database.forConfig("nc.mysql") (see earlier message)What's odd is that I can initialize
DatabaseUrlDataSource directly in the shellscala> import slick.jdbc.DatabaseUrlDataSource
import slick.jdbc.DatabaseUrlDataSource
scala> new DatabaseUrlDataSource()
res7: slick.jdbc.DatabaseUrlDataSource = slick.jdbc.DatabaseUrlDataSource@15ff0f79ClassNotFoundException during database initialization, but now I'm facing a different error java.lang.NullPointerException
at slick.jdbc.DriverDataSource.getConnection(DriverDataSource.scala:101)
at slick.jdbc.DataSourceJdbcDataSource.createConnection(JdbcDataSource.scala:68)
at slick.jdbc.JdbcBackend$BaseSession.<init>(JdbcBackend.scala:494)
at slick.jdbc.JdbcBackend$DatabaseDef.createSession(JdbcBackend.scala:46)
at slick.jdbc.JdbcBackend$DatabaseDef.createSession(JdbcBackend.scala:37)
at slick.basic.BasicBackend$DatabaseDef.acquireSession(BasicBackend.scala:250)
at slick.basic.BasicBackend$DatabaseDef.acquireSession$(BasicBackend.scala:249)
at slick.jdbc.JdbcBackend$DatabaseDef.acquireSession(JdbcBackend.scala:37)
at slick.basic.BasicBackend$DatabaseDef$$anon$3.run(BasicBackend.scala:275)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)Database.forURL and try to write to the db, the mysql driver connects using a different database URL and I get an error saying the table doesn't exist. Anyone experience something like this?