I have a single table
DB_SMS
----------------------------------------
contactId | messageText | to | createdAt
I want fetch the most recently created record for each contactId. For example:
contactId | messageText | to | createdAt
1 | msg01 | a | 2015-04-20
1 | msg02 | b | 2015-04-21
2 | msg03 | c | 2015-04-20
3 | msg04 | d | 2015-04-20
3 | msg05 | w | 2015-04-22
Required result
contactId | messageText | to | createdAt
1 | msg02 | b | 2015-04-21
2 | msg03 | c | 2015-04-20
3 | msg05 | w | 2015-04-22
I am using following code
NSFetchRequest * theRequest = [NSFetchRequest fetchRequestWithEntityName:#"DB_SMS"];
[theRequest setResultType:NSDictionaryResultType];
[theRequest setPropertiesToFetch:#[#"contactId",#"messageText",#"to",#"createdAt"]];
[theRequest setPropertiesToGroupBy:#[#"contactId"]];
[theRequest setSortDescriptors:#[[NSSortDescriptor sortDescriptorWithKey:#"createdAt" ascending:NO]]];
NSArray * theArray = [theDbHandler.managedObjectContext executeFetchRequest:theRequest error:nil];
i'm getting following exception
SELECT clauses in queries with GROUP BY components can only contain properties named in the GROUP BY or aggregate functions
plz suggest some solution .
Related
I have a Cypher query that shows the following output:
+----------------
| usid | count |
+----------------
| "000" | 1 |
| "000" | 0 |
| "000" | 0 |
| "001" | 1 |
| "001" | 1 |
| "001" | 0 |
| "002" | 2 |
| "002" | 2 |
| "002" | 0 |
| "003" | 4 |
| "003" | 2 |
| "003" | 2 |
| "004" | 4 |
| "004" | 4 |
| "004" | 4 |
+----------------
How can I get the below result with the condition SUM(count) <= 9.
+----------------
| usid | count |
+----------------
| "000" | 1 |
| "001" | 2 |
| "002" | 4 |
| "003" | 8 |
+----------------
Note: I have used the below query to get the 1st table data.
MATCH (us:USER)
WITH us
WHERE us.count <= 4
RETURN us.id as usid, us.count as count;
I don't know how you get your original data, so I will just use a WITH clause and assume the data is there:
// original data
WITH usid, count
// aggregate and filter
WITH usid, sum(count) as new_count
WHERE new_count <= 9
RETURN usid, new_count
Based on the updated question, the new query would look like:
MATCH (us:USER)
WHERE us.count <= 4
WITH us.id as usid, sum(us.count) as count
WHERE new_count <= 9
RETURN usid, count
˙˙˙
How to combine distinct and max within join table below?
Table_details_usage
UID | VE_NO | START_MILEAGE | END_MILEAGE
------------------------------------------------
1 | ASD | 410000 | 410500
2 | JWQ | 212000 | 212350
3 | WYS | 521000 | 521150
4 | JWQ | 212360 | 212400
5 | ASD | 410520 | 410600
Table_service_schedule
SID | VE_NO | SV_ONMILEAGE | SV_NEXTMILEAGE
------------------------------------------------
1 | ASD | 400010 | 410010
2 | JWQ | 212120 | 222120
3 | WYS | 511950 | 521950
4 | JWQ | 212300 | 222300
5 | ASD | 410510 | 420510
How to get display as below (only max value)?
Get Max value from Table_service_schedule (SV_NEXTMILEAGE) and Get Max value from Table_details_usage (END_MILEAGE)
SID | VE_NO | SV_NEXTMILEAGE | END_MILEAGE
--------------------------------------------
5 | ASD | 420510 | 410600
4 | JWQ | 222300 | 212400
3 | WYS | 521950 | 521150
Something in the lines of:
SELECT
SID,
VE_NO,
SV_NEXTMILEAGE,
(select max(END_MILEAGE) from Table_details_usage d where d.VE_NO = s.VE_NO) END_MILEAGE
FROM Table_service_schedule s
WHERE SID = (SELECT max(SID) FROM Table_service_schedule s2 WHERE s2.VE_NO = s.VE_NO)
Probably could need to change the direct value ov SV_NEXTMILEAGE to max as well if the id:s aren't in order...
The title is a little confusing, so here is an example of the problem I'm facing.
Table:
FORM_QUESTION
Fields:
student_id
q1_ans
q2_ans
q3_ans
q4_ans
q5_ans
x--------------x----------x----------x----------x----------x----------x
| student_id | q1_ans | q2_ans | q3_ans | q4_ans | q5_ans |
x--------------x----------x----------x----------x----------x----------x
| 1 | A | D | B | B | E |
| 2 | D | C | B | A | D |
| 3 | B | C | D | A | B |
x--------------x----------x----------x----------x----------x----------x
The FORM_QUESTION table stores a student's answers for each question.
Here is information on the second table:
Table:
FORM_VALID_ANS
Fields:
question_id
valid_answer
x---------------x----------------x
| question_id | valid_answer |
x---------------x----------------x
| q1_ans | A |
| q1_ans | B |
| q2_ans | A |
| q2_ans | B |
| q2_ans | C |
| q2_ans | D |
| q3_ans | A |
| q4_ans | A |
| q4_ans | B |
| q5_ans | A |
x---------------x----------------x
The second table, FORM_VALID_ANS, stores the valid, acceptable answers for a particular question. So, according to the above table, here is the acceptable list of values for each question:
q1_ans: A, B
q2_ans: A, B, C, D
q3_ans: A
q4_ans: A, B
q5_ans: A
As you can see, the values for the FORM_VALID_ANS.valid_answer include only the question field names for FORM_QUESTION ("q1_ans", "q2_ans", "q3_ans", "q4_ans", and "q5_ans"). I need to check each students' answer to make sure it is a valid value that they can enter, which is specified in the FORM_VALID_ANS.valid_answer field.
The desired output, where XXX represents an invalid value, and all other values would be answered value:
x--------------x----------x----------x----------x----------x----------x
| student_id | q1_ans | q2_ans | q3_ans | q4_ans | q5_ans |
x--------------x----------x----------x----------x----------x----------x
| 1 | A | D | XXX | B | XXX |
| 2 | XXX | C | XXX | A | XXX |
| 3 | B | C | XXX | A | XXX |
x--------------x----------x----------x----------x----------x----------x
Is it possible to join these two tables together and produce these results (or similar results)?
I'm trying to setup my NSFetchRequest to core data to retrieve the rows "unique name which have greater rate"
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"rate = max(rate)"];
[request setPropertiesToFetch:#[#"name"]];
request.predicate = predicate;
[request setReturnsDistinctResults:YES];
But the above return only one row which have maximum rate.
required sample
name | rate | factor |
_______|______|________|
John | 3.2 | 7 |
Betty | 5.5 | 7 |
Betty | 7.1 | 2 |
Betty | 3.1 | 2 |
Edward | 5.5 | 1 |
Edward | 4.5 | 2 |
John | 4.3 | 4 |
How would i set up the request to return an array like
John, 4.3, 4
Betty, 7.1, 2
Edward,5.5, 1
And can we sort it (sort by rate desc) with the fetch query itself ? So the result array will be
Betty, 7.1, 2
Edward,5.5, 1
John, 4.3, 4
Set the propertiesToGroupBy property of your NSFetchRequest to include "name".
Note: you may have to aggregate the factor column in some way as well, for the group by to work.
I have entity employee_detail in coredata
name | rate | factor |
_______|______|________|
John | 3.2 | 4 |
Betty | 5.5 | 7 |
Betty | 2.1 | 2 |
Betty | 3.1 | 2 |
Edward | 4.5 | 5 |
John | 2.3 | 4 |
i want unique object base on attribute name
O/P should be
name | rate | factor |
_______|______|________|
John | 3.2 | 4 |
Betty | 5.5 | 7 |
Edward | 4.5 | 5 |
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:#"employee_detail"];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"employee_detail" inManagedObjectContext:self.managedObjectContext];
fetchRequest.resultType = NSDictionaryResultType;
fetchRequest.propertiesToFetch = [NSArray arrayWithObject:[[entity propertiesByName] objectForKey:#"name"]];
fetchRequest.returnsDistinctResults = YES;
NSArray *dictionaries = [self.managedObjectContext executeFetchRequest:fetchRequest error:nil];
NSLog (#"names: %#",dictionaries);