i'm trying to delete n rows from database and n is variable should be given in the api method like deleting the last 10 boxes of items in supermarket which means they are sold so how i would do so i'm using spring data rest i don't know how to write the query in the repository and how i would get the variable n and use it in the sql query also i should check if that number of rows exist before deleting
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I successfully deal with selection from SAP Tables by using RFC function module. Issue I'm facing is to understand best practice of selecting data from arbitrary row.
Example: First RFC call will fetch 1000 records from KNA1 (I will log in custom transparent table how many records in total where considered so far).
New RFC Call should take next 1000 rows but starting from row 1000 till 2000. Is there some elegant way of dealing with this situation?
Using of Cursor is not possible since there are 2 consecutive calls of same RFC cursor value will be reset.
Otherwise I should always selecting everything and distinguish requested data by looping the total data which will consume a lot of time.
Thanks for any suggestions!
Use OFFSET
In the SELECT with OFFSET:
SELECT * FROM kna1
UP TO 1000 ROWS
OFFSET (lv_offset)
WHERE ...
ORDER BY ...
If lv_offset contains 2000 for example, it will return the rows 2001-3000 by the ordering.
According to the online help, you have to use ORDER BY in the SELECT.
It is possible to return nested results(RECORD type) if noflatten_results flag is specified but it is possible to just view them on screen without writing it to table first.
for example, here is an simple user table(my actual table is big large(400+col with multi-level of nesting)
ID,
name: {first, last}
I want to view record particular user & display in my applicable, so my query is
SELECT * FROM dataset.user WHERE id=423421 limit 1
is it possible to return the result directly?
You should write your output to "temp" table with noflatten_results option (also respective expiration to be set to purge table after it is used) and serve your client out of this temp table. All "on-fly"
Have in mind that no matter how small "temp" table is - if you will be querying it (in above second step) you will be billed for at least 10MB, so you better use Tabledata.list API in this step (https://cloud.google.com/bigquery/docs/reference/v2/tabledata/list) which is free!
So if you try to get repeated records it will fail on the interface/BQ console with the error:
Error: Cannot output multiple independently repeated fields at the same time.
and in order to get past this error is to FLATTEN your output.
I know that I can use something like:
=First(Fields!Group.Value, "helloWorldReport")
=Last(Fields!Group.Value, "helloWorldReport")
To get the first and last records of my dataset. However, how can I get the ones in between them? What if I have 9 or 10 other records, can I programmaticaly access to a specific record, i.e. record number 7?
I am having an issue with inserting records into CoreData after parsing XML webservice. I parse the web service and store the records in an array and the count i get for array is 239. Before i insert the data i see the array count for existing core data.Its 0 records. So now i push the data into the coredata. All goes well. But, i end up with 1 extra record. A duplicate for an existing record. The count i get is 240.HOw is it happening?I did this process with another table.I got from the webservice for this new table table this time 113 records. After i insert the data, the table has 114 records and 1 extra record(duplicate again). I check using the firefox add on sqlite manager. Peculiar thing to note is that there is a field (not the one i designed) called Z_OPT, which has the value 239 (remaining fields identical) and for the table with 113 records the 114th record has z_OPT= 113(remaining fields identical).Did this happen to anyone?Any information would be of great help. If you need more information, please ask.Thanks...
I am having a problem trying to achieve the following:
I'd like to have a page with 'infinite' scrolling functionality and all the results fetched to be sorted by certain attributes. The way the code currently works is, it places the query, sorts the results, and displays them. The problem is, that once the user reaches the bottom of the page and new query is placed, the results from this query are sorted, but in its own context. That is, if you have a total of 100 results, and the first query display only 50, then they are sorted. But the next query (for the next 50) sorts the results only based on these 50 results, not based on the 100 (total results).
So, do I have to fetch all the results at once, sort them, and then apply some pagination logic to them or there's a way for MongoDB to actually have infinite scrolling (AJAX requests) with sorting applying to the results?
There's a few ways to do this with MongoDB. You can use the .skip() and .limit() commands (documented here: http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-CursorMethods) to apply pagination to the query.
Alternatively, you could add a clause to your query like: {sorted_field : {$gt : <value from last record>}}. In other words, filter out matches of the query whose sorted value is less than that of the last resulting item from the current page of results. For example, if page 1 of results returns documents A through D, then to retrieve the next page 2 you repeat the same query with the additional filter x > D.
Let me preface this by saying that I have no experience with MongoDB (though I am aware that it is a NoSQL database).
This question, however, is somewhat of a general database one (you'd probably get more responses tagging it as such). I've implemented such a feature using Cassandra (another, albiet quite different NoSQL database), however the same principles apply.
Use the sorted-by attribute of the last retrieved record, and conduct a range search based on it in the database. So, assuming your database consists of the following set of letters:
A
B
C
D
E
F
G
..and you were retrieving 2 letters at a time, you'd retrieve A, B first. When more records are needed, you'd use B to conduct a range search on the set of letters in the database. In plain English this would be something like:
Get the letters that appear after B, limit the results to 2
From a brief look at the MongoDB tutorial, it looks like you have conditional operators to help you implement this.