I have a super column family and everything works well when I query like this:
private static Cluster cluster = HFactory.getOrCreateCluster("cluster1", "localhost:9160");
private static Keyspace keyspace = HFactory.createKeyspace("keyspace1",cluster);
private static Serializer se = StringSerializer.get();
SuperColumnQuery<String, String, String, String> scq = HFactory.createSuperColumnQuery(keyspace, se, se, se, se);
scq.setColumnFamily("step_wise_stats")
.setKey("1001")
.setSuperName("124");
QueryResult<HSuperColumn<String, String, String>> qres = scq.execute();
System.out.println(qres.get());
But there are more super names under key 1001 such as 125, 126 etc.. And those are dynamic too (I don't know those names in advance). How do I query them all?
Many of experts and documentation suggest that to go with composite column is far better than that of Super Column because lack of secondary indices in that...so if possible use Composite Column.Otherwise in this case you should use timeUUID in place of your dynamic values and try with MultigetSubSliceQuery , make changes with below code,this might increase your programming efforts to generate required result
ArrayList<String> listco = new ArrayList<String>();
listco.add("1001");
listco.add("1002");
MultigetSubSliceQuery<String,String, String, String> rangeSlicesQuery =
HFactory.
createMultigetSubSliceQuery(keyspace,stringSerializer, stringSerializer, stringSerializer, stringSerializer);
rangeSlicesQuery.setColumnFamily("step_wise_stats");
rangeSlicesQuery.setSuperColumn("your super column");
rangeSlicesQuery.setKeys(listco);
rangeSlicesQuery.setRange("", "", false, 1000);
QueryResult<Rows<String, String, String>> result = rangeSlicesQuery.execute();
Related
I have been looking for a solution everywhere on the internet but nowhere I can see a single script which lets me read the name of a variable as a string in Godot 3.1
What I want to do:
Save path names as variables.
Compare the name of the path variable as a string to the value of another string and print the path value.
Eg -
var Apple = "mypath/folder/apple.png"
var myArray = ["Apple", "Pear"]
Function that compares the Variable name as String to the String -
if (myArray[myposition] == **the required function that outputs variable name as String**(Apple) :
print (Apple) #this prints out the path.
Thanks in advance!
I think your approach here might be a little oversimplified for what you're trying to accomplish. It basically seems to work out to if (array[apple]) == apple then apple, which doesn't really solve a programmatic problem. More complexity seems required.
First, you might have a function to return all of your icon names, something like this.
func get_avatar_names():
var avatar_names = []
var folder_path = "res://my/path"
var avatar_dir = Directory.new()
avatar_dir.open(folder_path)
avatar_dir.list_dir_begin(true, true)
while true:
var avatar_file = avatar_dir.get_next()
if avatar_file == "":
break
else:
var avatar_name = avatar_file.trim_suffix(".png")
avatar_names.append(avatar_name)
return avatar_names
Then something like this back in the main function, where you have your list of names you care about at the moment, and for each name, check the list of avatar names, and if you have a match, reconstruct the path and do other work:
var some_names = ["Jim","Apple","Sally"]
var avatar_names = get_avatar_names()
for name in some_names:
if avatar_names.has(name):
var img_path = "res://my/path/" + name + ".png"
# load images, additional work, etc...
That's the approach I would take here, hope this makes sense and helps.
I think the current answer is best for the approach you desire, but the performance is pretty bad with string comparisons.
I would suggest adding an enumeration for efficient comparisons. unfortunately Godot does enums differently then this, it seems like your position is an int so we can define a dictionary like this to search for the index and print it out with the int value.
var fruits = {0:"Apple",1:"Pear"}
func myfunc():
var myposition = 0
if fruits.has(myposition):
print(fruits[myposition])
output: Apple
If your position was string based then an enum could be used with slightly less typing and different considerations.
reference: https://docs.godotengine.org/en/latest/tutorials/scripting/gdscript/gdscript_basics.html#enums
Can't you just use the str() function to convert any data type to stirng?
var = str(var)
I have two classes:
public class ClassOne {
private String id;
private String name;
private String school;
private String score; //Default score is null
..getters and setters..
}
public class ClassTwo {
private String id;
private String marks;
..getters and setters..
}
And, I have two Lists of the above classes,
List<ClassOne> listOne;
List<ClassTwo> listTwo;
How can I compare two list and assign marks from listTwo to score of listOne based on the criteria if the IDs are equal. I know, we can use two for loops and do it. But I want to implement it using Java8 streams.
List<ClassOne> result = new ArrayList<>();
for(ClassOne one : listOne) {
for(ClassTwo two : listTwo) {
if(one.getId().equals(two.getId())) {
one.setScore(two.getmarks());
result.add(one);
}
}
}
return result;
How can I implement this using Java8 lambda and streams?
Let listOne.size() is N and listTwo.size() is M.
Then 2-for-loops solution has complexity of O(M*N).
We can reduce it to O(M+N) by indexing listTwo by ids.
Case 1 - assuming listTwo has no objects with the same id
// pair each id with its marks
Map<String, String> marksIndex = listTwo.stream().collect(Collectors.toMap(ObjectTwo::getId, ObjectTwo::getMarks));
// go through list of `ObjectOne`s and lookup marks in the index
listOne.forEach(o1 -> o1.setScore(marksIndex.get(o1.getId())));
Case 2 - assuming listTwo has objects with the same id
final Map<String, List<ObjectTwo>> marksIndex = listTwo.stream()
.collect(Collectors.groupingBy(ObjectTwo::getId, Collectors.toList()));
final List<ObjectOne> result = listOne.stream()
.flatMap(o1 -> marksIndex.get(o1.getId()).stream().map(o2 -> {
// make a copy of ObjectOne instance to avoid overwriting scores
ObjectOne copy = copy(o1);
copy.setScore(o2.getMarks());
return copy;
}))
.collect(Collectors.toList());
To implement copy method you either need to create a new object and copy fields one by one, but in such cases I prefer to follow the Builder pattern. It also results in more "functional" code.
Following code copies marks from ObjectTwo to score in ObjectOne, if both ids are equal, it doesn't have intermediate object List<ObjectOne> result
listOne.stream()
.forEach(one -> {listTwo.stream()
.filter(two -> {return two.getId().equals(one.getId());})
.limit(1)
.forEach(two -> {one.setScore(two.getMarks());});
});
This should work.
Map<String, String> collect = listTwo.stream().collect(Collectors.toMap(ObjectTwo::getId, ObjectTwo::getMarks));
listOne
.stream()
.filter(item -> collect.containsKey(item.getId()))
.forEach(item -> item.setScore(collect.get(item.getId())));
A property from my object (oJobs) is as follows:
Private _brandlist As List(Of DAL.Brand)
Public Property PostBrandList() As List(Of DAL.Brand)
Get
Return _brandlist
End Get
Set(ByVal value As List(Of DAL.Brand))
_brandlist = value
End Set
End Property
In the database, the brand list is stored as a string separated by comma e.g. the column 'brands' can be a string '3,45,2' where each number represents an id of a brand stored in another table.
my select query is as below:
Dim jobposts As List(Of oJobs) = From j In db.JobPostings
Select New oJobs With { 'hiding all others for code brevity
.PostBrandList = 'problem is here'
}
Since j.BrandList will return a string, I will need to split that string and for each number, run another query to finally return and assign a List(Of DAL.Brand) into .PostBrandList
For those who might ask "what have you tried?",
I have run the query, then did a for each to add the list of brands later - succeeded but not optimal
Coded a function that takes the list as a parameter and returns a separate list of objects - very silly.
Also, I am not allowed to normalize the DB :(
Not tested and might need some tweaking but heres one idea. you will also need to change your property to an IEnumerable rather than List. Because the second linq query is embedded within the first, I believe it should execute it all as one query, but you should check it to make sure.
Dim jobposts As List(Of oJobs) = From j In db.JobPostings
Select New oJobs With { 'hiding all others for code brevity
.PostBrandList = From b In db.Brands Where j.Brands = b.ID Or j.Brands.StartsWith(b.ID & ",") Or j.Brands.EndsWith("," & b.ID) Or j.Brands.Contains("," & b.ID & ",") Select b
}
In c# you can use
.Select(x=>new {x.BrandList})
.ToList() //Materialize first before calling function
.Select(x=> new oJobs{
PostBrandList =
db.Brands.Where(z=>
x.BrandList
.Split(',')
.Select(y=>int.Parse(y.Trim()))
.Contains(z.Id))
.ToList()
});
Note that you must materialize entity first before calling String.Split
I don't know how to translate that to VB.NET.
Of course it will cause SELECT n+1 problem because you can't use join.
If you can't normalize table, my other suggestion is to create indexed view (sql server), so you can use join and improve performance.
Indexed view https://msdn.microsoft.com/en-us/library/ms191432.aspx
You could try it with the Let statement:
Dim jobposts As List(Of oJobs) = From j In db.JobPostings
/* li in the LINQ Statement represents one string value from the BrandList list */
Let postBrandElemsList = j.BrandList.Split(',').Select(Function(li) New DAL.Brand With { ... /* Field initializatione of the Class DAL.Brand here */ }
Select New oJobs With
{
.PostBrandList = postBrandElemsList
}
I'm sorry for the probably bad VB.NET syntax, you should check this when implementing it in your code.
Maybe you would just want to use the Split function on the column brands into an array and iterate through the result, using the Find function to retrieve the brand objects?
How can iterate on JavaPairRDD. I have done a group by and got back a RDD as below JavaPairRDD (Tuple 7 set of Strings and List of Objects)
Now I have to iterate over this RDD and do some calculations like FOR EACH in Pig.
Basically I would like to iterate the key and the list of values and do some operations and then return back a JavaPairRDD?
JavaPairRDD<Tuple7<String, String,String,String,String,String,String>, List<Records>> sizes =
piTagRecordData.groupBy( new Function<Records, Tuple7<String, String,String,String,String,String,String>>() {
private static final long serialVersionUID = 2885738359644652208L;
#Override
public Tuple7<String, String,String,String,String,String,String> call(Records row) throws Exception {
Tuple7<String, String,String,String,String,String,String> compositeKey = new Tuple7<String, String, String, String, String, String, String>(row.getAsset_attribute_id(),row.getDate_time_value(),row.getOperation(),row.getPi_tag_count(),row.getAsset_id(),row.getAttr_name(),row.getCalculation_type());
return compositeKey;
}
});
After this I want to perform FOR EACH member of sizes (JavaPairRDD), operation -- something like
rejected_records = FOREACH sizes GENERATE FLATTEN(Java function on the List of Records based on the group key
I am using Spark 0.9.0
Even though you are talking about "FOR EACH", it really sounds like you want the flatMap operation, since you want to produce new values and flatten them. This is available for Java RDDs, including a JavaPairRDD.
You can use void foreach(VoidFunction<T> f) method. More info and methods: https://spark.apache.org/docs/1.1.0/api/java/org/apache/spark/api/java/JavaRDDLike.html#foreach(org.apache.spark.api.java.function.VoidFunction)
if you want to view some value of JavaPairRDD, I would do like this
for (Tuple2<String, String> test : pairRdd.take(10)) //or pairRdd.collect()
{
System.out.println(test._1);
System.out.println(test._2);
}
Note:Tuple2 (assuming you have strings inside the JavaPairRDD), change the datatype according to the data type stored in the JavaPairRDD.
I am relatively new to PigScript. I would like to know if there is a way of passing parameters to Java UDFs in Pig?
Here is the scenario:
I have a log file which have different columns (each representing a Primary Key in another table). My task is to get the count of distinct primary key values in the selected column.
I have written a Pig script which does the job of getting the distinct primary keys and counting them.
However, I am now supposed to write a new UDF for each column. Is there a better way to do this? Like if I can pass a row number as parameter to UDF, it avoids the need for me writing multiple UDFs.
The way to do it is by using DEFINE and the constructor of the UDF. So here is an example of a customer "splitter":
REGISTER com.sample.MyUDFs.jar;
DEFINE CommaSplitter com.sample.MySplitter(',');
B = FOREACH A GENERATE f1, CommaSplitter(f2);
Hopefully that conveys the idea.
To pass parameters you do the following in your pigscript:
UDF(document, '$param1', '$param2', '$param3')
edit: Not sure if those params need to be wrappedin ' ' or not
while in your UDF you do:
public class UDF extends EvalFunc<Boolean> {
public Boolean exec(Tuple input) throws IOException {
if (input == null || input.size() == 0)
return false;
FileSystem fs = FileSystem.get(UDFContext.getUDFContext().getJobConf());
String var1 = input.get(1).toString();
InputStream var1In = fs.open(new Path(var1));
String var2 = input.get(2).toString();
InputStream var2In = fs.open(new Path(var2));
String var3 = input.get(3).toString();
InputStream var3In = fs.open(new Path(var3));
return doyourthing(input.get(0).toString());
}
}
for example
Yes, you can pass any parameter in the Tuple parameter input of your UDF:
exec(Tuple input)
and access it using
input.get(index)