DynamoDB Java SDK query to match items in a list - amazon-dynamodb

I'm trying to use SQL IN clause kind of feature in dynamoDB. I tried using withFilterExpression but I'm not sure how to do it. I looked at similar questions as they were too old. Is there a better method to do this? This is the segment of code I have got. I have used a static List as example but it is actually dynamic.
def getQuestionItems(conceptCode : String) = {
val qIds = List("1","2","3")
val querySpec = new QuerySpec()
.withKeyConditionExpression("concept_id = :c_id")
.withFilterExpression("question_id in :qIds") // obviously wrong
.withValueMap(new ValueMap()
.withString(":c_id", conceptCode));
questionsTable.query(querySpec);
}
I need to pass qID list to fetch results similar to IN clause in SQL Query.

Please refer to this answer. Basically you need to form key list/value list dynamically
.withFilterExpression("question_id in (:qId1, :qId2, ... , :qIdN)")
.withValueMap(new ValueMap()
.withString(":qId1", ..) // just do this for each element in the list in a loop programmatically
....
.withString(":qIdN", ..)
);
Mind there is a restriction on maxItems in 'IN'

Related

Populating an Apex Map from a SOQL query

// I have a custom metadata object named boatNames__mdt and I'm using two methods to get a list of picklist values in a String[];
First Method
Map<String, boatNames__mdt> mapEd = boatNames__mdt.getAll();
string boatTypes = (string) mapEd.values()[0].BoatPick__c;
// BoatPick__c is a textarea field (Eg: 'Yacht, Sailboat')
string[] btWRAP = new string[]{};
**btWRAP**.addAll(boatTypes.normalizeSpace().split(','));
Second Method
string[] strL = new string[]{};
Schema.DescribeFieldResult dfr = Schema.SObjectType.boatNames__mdt.fields.BoatTypesPicklist__c;
// BoatTypesPicklist__c is a picklist field (Picklist Values: 'Yacht, Sailboat')
PicklistEntry[] picklistValues = dfr.getPicklistValues();
for (PicklistEntry pick : picklistValues){
**strl**.add((string) pick.getLabel());
}
Map with SOQL query
Map<Id, BoatType__c> boatMap = new Map<Id, BoatType__c>
([Select Id, Name from BoatType__c Where Name in :btWRAP]);
When I run the above Map with SOQL query(btWRAP[]) no records show up.
But when I used it using the strl[] records do show up.
I'm stunned!
Can you please explain why two identical String[] when used in exact SOQL queries behave so different?
You are comparing different things so you get different results. Multiple fails here.
mapEd.values()[0].BoatPick__c - this takes 1st element. At random. Are you sure you have only 1 element in there? You might be getting random results, good luck debugging.
normalizeSpace() and trim() - you trim the string but after splitting you don't trim the components. You don't have Sailboat, you have {space}Sailboat
String s = 'Yacht, Sailboat';
List<String> tokens = s.normalizeSpace().split(',');
System.debug(tokens.size()); // "2"
System.debug(tokens); // "(Yacht, Sailboat)", note the extra space
System.debug(tokens[1].charAt(0)); // "32", space's ASCII number
Try splitting by "comma, optionally followed by space/tab/newline/any other whitespace symbol": s.split(',\\s*'); or call normalize in a loop over the split's results?
pick.getLabel() - in code never compare using picklist labels unless you really know what you're doing. Somebody will translate the org to German, French etc and your code will break. Compare to getValue()

How do I get a value from a dictionary when the key is a value in another dictionary in Lua?

I am writing some code where I have multiple dictionaries for my data. The reason being, I have multiple core objects and multiple smaller assets and the user must be able to choose a smaller asset and have some function off in the distance run the code with the parent noted.
An example of one of the dictionaries: (I'm working in ROBLOX Lua 5.1 but the syntax for the problem should be identical)
local data = {
character = workspace.Stores.NPCs.Thom,
name = "Thom", npcId = 9,
npcDialog = workspace.Stores.NPCs.Thom.Dialog
}
local items = {
item1 = {
model = workspace.Stores.Items.Item1.Main,
npcName = "Thom",
}
}
This is my function:
local function function1(item)
if not items[item] and data[items[item[npcName]]] then return false end
end
As you can see, I try to index the dictionary using a key from another dictionary. Usually this is no problem.
local thisIsAVariable = item[item1[npcName]]
but the method I use above tries to index the data dictionary for data that is in the items dictionary.
Without a ton of local variables and clutter, is there a way to do this? I had an idea to wrap the conflicting dictionary reference in a tostring() function to separate them - would that work?
Thank you.
As I see it, your issue is that:
data[items[item[npcName]]]
is looking for data[“Thom”] ... but you do not have such a key in the data table. You have a “name” key that has a “Thom” value. You could reverse the name key and value in the data table. “Thom” = name

Correct parameter binding for SELECT WHERE .. LIKE using fmdb?

First time user of fmdb here, trying to start off doing things correctly. I have a simple single table that I wish to perform a SELECT WHERE .. LIKE query on and after trying several of the documented approaches, I can't get any to yield the correct results.
e.g.
// 'filter' is an NSString * containing a fragment of
// text that we want in the 'track' column
NSDictionary *params =
[NSDictionary dictionaryWithObjectsAndKeys:filter, #"filter", nil];
FMResultSet *results =
[db executeQuery:#"SELECT * FROM items WHERE track LIKE '%:filter%' ORDER BY linkNum;"
withParameterDictionary:params];
Or
results = [db executeQuery:#"SELECT * FROM items WHERE track LIKE '%?%' ORDER BY linkNum;", filter];
Or
results = [db executeQuery:#"SELECT * FROM items WHERE track LIKE '%?%' ORDER BY linkNum;" withArgumentsInArray:#[filter]];
I've stepped through and all methods converge in the fmdb method:
- (FMResultSet *)executeQuery:(NSString *)sql withArgumentsInArray:(NSArray*)arrayArgs orDictionary:(NSDictionary *)dictionaryArgs orVAList:(va_list)args
Depending on the approach, and therefore which params are nil, it then either calls sqlite3_bind_parameter_count(pStmt), which always returns zero, or, for the dictionary case, calls sqlite3_bind_parameter_index(..), which also returns zero, so the parameter doesn't get slotted into the LIKE and then the resultSet from the query is wrong.
I know that this is absolutely the wrong way to do it (SQL injection), but it's the only way I've managed to have my LIKE honoured:
NSString *queryString = [NSString stringWithFormat:#"SELECT * FROM items WHERE track LIKE '%%%#%%' ORDER BY linkNum;", filter];
results = [db executeQuery:queryString];
(I've also tried all permutations but with escaped double-quotes in place of the single quotes shown here)
Update:
I've also tried fmdb's own …WithFormat variant, which should provide convenience and protection from injection:
[db executeQueryWithFormat:#"SELECT * FROM items WHERE track LIKE '%%%#%%' ORDER BY linkNum;", filter];
Again, stepping into the debugger I can see that the LIKE gets transformed from this:
… LIKE '%%%#%%' ORDER BY linkNum;
To this:
… LIKE '%%?%' ORDER BY linkNum;
… which also goes on to return zero from sqlite3_bind_parameter_count(), where I would expect a positive value equal to "the index of the largest (rightmost) parameter." (from the sqlite docs)
The error was to include any quotes at all:
[db executeQuery:#"SELECT * FROM items WHERE track LIKE ? ORDER BY linkNum;", filter];
… and the % is now in the filter variable, rather than in the query.

Dynamics AX 2012 AOT Object Lookup

Anyone have sample lookup code for AOT objects? (or know where to find the one they use for the AX properties window)
I need to replicate the functionality that you see in several fields in the properties window. The ExtendedDataType field is a good example. Type a few letters, hit the down arrow, and a filtered list of AOT ExtendedDataType objects appears.
I've been trying to use treeNode findChildren to build my custom lookup list, but it is very slow. Whatever method AX is using happens instantly.
Thanks
Try this:
Dictionary d = new Dictionary();
int i;
int cnt = d.tableCnt();
TableId tableId;
str nameForLookup;
for (i = 1; i <= cnt; i++)
{
tableId = d.tablecnt2id(i);
nameForLookup = tableid2name(tableId);
}
Queries to the Model/Util*Element tables will not be cached, and are relatively slow due to the number of records that they contain.
There may be other factors slowing down execution as well. If you are on 2012, for lookups, you may want to build a temp table with an XDS() method, which populates itself using the above code, then you can simply select from that table (and it will be cached for the session):
create a SQL Temp table (e.g. with a name like MyTableLookup), add a name column
add a method like this:
public RefreshFrequency XDS()
{
MyTableLookup tableLookup;
ttsbegin;
// Use the above code to insert records into tableLookup
ttscommit;
return RefreshFrequency::PerSession;
}
bind your form to MyLookupTable
You may develop an estándar EDT linked to the UtilElement Table properly filtered. This will show a list of objects and will have same functionality of all table-linked text fields.

What's wrong with my filter query to figure out if a key is a member of a list(db.key) property?

I'm having trouble retrieving a filtered list from google app engine datastore (using python for server side). My data entity is defined as the following
class Course_Table(db.Model):
course_name = db.StringProperty(required=True, indexed=True)
....
head_tags_1=db.ListProperty(db.Key)
So the head_tags_1 property is a list of keys (which are the keys to a different entity called Headings_1).
I'm in the Handler below to spin through my Course_Table entity to filter the courses that have a particular Headings_1 key as a member of the head_tags_1 property. However, it doesn't seem like it is retrieving anything when I know there is data there to fulfill the request since it never displays the logs below when I go back to iterate through the results of my query (below). Any ideas of what I'm doing wrong?
def get(self,level_num,h_key):
path = []
if level_num == "1":
q = Course_Table.all().filter("head_tags_1 =", h_key)
for each in q:
logging.info('going through courses with this heading name')
logging.info("course name filtered is %s ", each.course_name)
MANY MANY THANK YOUS
I assume h_key is key of headings_1, since head_tags_1 is a list, I believe what you need is IN operator. https://developers.google.com/appengine/docs/python/datastore/queries
Note: your indentation inside the for loop does not seem correct.
My bad apparently '=' for list is already check membership. Using = to check membership is working for me, can you make sure h_key is really a datastore key class?
Here is my example, the first get produces result, where the 2nd one is not
import webapp2 from google.appengine.ext import db
class Greeting(db.Model):
author = db.StringProperty()
x = db.ListProperty(db.Key)
class C(db.Model): name = db.StringProperty()
class MainPage(webapp2.RequestHandler):
def get(self):
ckey = db.Key.from_path('C', 'abc')
dkey = db.Key.from_path('C', 'def')
ekey = db.Key.from_path('C', 'ghi')
Greeting(author='xxx', x=[ckey, dkey]).put()
x = Greeting.all().filter('x =',ckey).get()
self.response.write(x and x.author or 'None')
x = Greeting.all().filter('x =',ekey).get()
self.response.write(x and x.author or 'None')
app = webapp2.WSGIApplication([('/', MainPage)],
debug=True)

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