Question: here's my sample data:

```
id  name      source
--------------------------
1   aaa       source1
2   bbb       source1
3   ccc       source1
4   ddd       source1
5   aaa       source2
6   bbb       source2
3   ccc       source2
4   ddd       source2
7   eee       source2

```

I'm trying to query all records where the value from "name" only occurs once (is unique) - so the desired output would be:

```
id  name      source
--------------------------
7   eee       source2

```

I've tried a combination of `GROUP BY name` and `HAVING` but it didn't work

```
SELECT name, source, COUNT(*) AS total FROM data
GROUP BY name
HAVING total=1

```

any ideas?

PS: how can i filter for "source"? `WHERE source = "source2"` won't help ..

Answer: 
First of all, the SLF4J messages are only warnings and can be ignored. They most probably have nothing to do with `Exception in thread "main"`.

They mean that some code is trying to use slf4j api, but no implementation handles what to do with these logs. You may get rid of the warnings by adding to your classpath a working implementation of the SLF4j, e.g. [org.slf4j:slf4j-simple](https://mvnrepository.com/artifact/org.slf4j/slf4j-simple) to make the logs show in the console or [org.slf4j:slf4j-nop](https://mvnrepository.com/artifact/org.slf4j/slf4j-nop) to ignore any logging explicitly or [one of a number of other logging framework integration options](https://stackoverflow.com/questions/54652836/slf4j-found-slf4j-api-dependency-but-no-providers-were-found).
You have to remove **test** scope in your dependency of slf4j simple dependency. This could be one of the reasons.