DynamoDB “OR” conditional Range query -


let's assume table looks like:

code    |startdate  |enddate    |additional attributes...  abc     |11-24-2015 |11-26-2015 | ....  abc     |12-12-2015 |12-15-2015 | ....  abc     |10-05-2015 |10-10-2015 | ....  pqr     |03-24-2015 |03-27-2015 | ....  pqr     |05-04-2015 |05-08-2015 | ....

provided code (c) , date range (x, y), need able query items like:

query => (code = c) , ((startdate between x , y) or (enddate between x , y))

i planning use primary key hash , range key (code, startdate) additional lsi (enddate) , query on it. not sure if there way achieve this. don't want use scan operation seems scan entire table costly.

also, achieve in single query.

one option using query , filterexpression. no need define lsi on case. have query hash key eq operator , narrow results filter expression. here example java sdk:

table table = dynamodb.gettable(tablename);  map<string, object> expressionattributevalues = new hashmap<string, object>(); expressionattributevalues.put(":x", "11-24-2015"); expressionattributevalues.put(":y", "11-26-2015");  queryspec spec = new queryspec()     .withhashkey("code", "codevaluehere")     .withfilterexpression("(startdate between :x , :y) or (enddate between :x , :y)")     .withvaluemap(expressionattributevalues);   itemcollection<queryoutcome> items = table.query(spec);  iterator<item> iterator = items.iterator();  while (iterator.hasnext()) {     system.out.println(iterator.next().tojsonpretty()); }

see specifying conditions condition expressions more details.

additionally, although previous query uses hash key , can still group records range key containing dates in following format:

startdate#enddate

table structure:

code    daterange             |startdate  |enddate         abc     11-24-2015#11-26-2015 |11-24-2015 |11-26-2015    abc     12-12-2015#12-15-2015 |12-12-2015 |12-15-2015  abc     10-05-2015#10-10-2015 |10-05-2015 |10-10-2015  pqr     03-24-2015#03-27-2015 |03-24-2015 |03-27-2015  pqr     05-04-2015#05-08-2015 |05-04-2015 |05-08-2015

this way if happen query hash key still records sorted dates. also, believe idea follow advice given unambiguous date format.nu


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