I was wondering if it is possible to do a select * where value is in Java String[] or do I need to build a string of values from the string array first?
I am trying to find the best way of doing this technically without singular selects or building a string of values from the array.
Thanks for your time.
String[] lookupValues = new String[]{"1", "2", "3", "4"};
Select * from database where value in (lookupvalues)
try Arrays.toString(lookupvalues) or write a utility function.
public String toString(String[] values, boolean addQuotes) {
StringBuilder buff = new StringBuilder();
for(String value : values) {
if(addQuotes) {
buff.append(String.format("\"%s\"", value)).append(",");
} else {
buff.append(value).append(",");
}
}
buff.deleteCharAt(buff.length()-1); // delete the last comma
return buff.toString();
}
Are you looking to search for a string in array? If yes, you might want to look at Collections.binarySearch() or Arrays.binarySearch() - but please not that the collections or arrays need to be sorted before doing binary search
I know that this is not a direct answer to your question considering only arrays. I suggest you to use Guava since it offers a implementation of filter on Java Collections. Using proven libraries will give you flexibility if you use different kind of filters.
You can easily convert your array into proper collection
String[] lookupValues = new String[]{"1", "2", "3", "4"};
List<String> list = new ArrayList<String>(Arrays.asList(lookupValues));
And filter it with Guava filters:
Collection<String> filtered = Collections2.filter(list,
Predicates.containsPattern("3"));
print(filtered);
will find
3
If you want filtered collection as a list, you can use this something like this from Guava:
List<String> filteredList = Lists.newArrayList(Collections2.filter(
list, Predicates.containsPattern("3")));
