I am creating a composite key with artist and song in dynamo db. artist as a primary key and song as an sort key. i'm aware that query might be slow and expensive given how dynamo db works and how filter is applied, is it possible to apply filter to multiple attribute and how does it look like , for example - query all the records by an artist (joe) in a particular genre (country) with rating higher than 7
id | artist | song | albumTitle | Price | Genre | rating
1 | TI | hello | south | 90 | Rap | 7.0
2 | joe | good | free | 87 | pop | 8
3 | joe | bye | one | 99 | country| 7
4 | joe | beat | one | 99 | country| 5
5 | joe | sun | one | 99 | country| 9
Related
inspired from this How to get most recent data from DynamoDB for each primary partition key?
I have a table in dynamodb. It stores account stats. It's possible that the account stats will be updated several times per day. So table records may look like:
+------------+--------------+-------+-------+
| account_id | record_id | views | stars |
+------------+--------------+-------+-------+
| 3 | 2019/03/16/1 | 29 | 3 |
+------------+--------------+-------+-------+
| 2 | 2019/03/16/2 | 130 | 21 |
+------------+--------------+-------+-------+
| 1 | 2019/03/16/3 | 12 | 2 |
+------------+--------------+-------+-------+
| 2 | 2019/03/16/1 | 57 | 12 |
+------------+--------------+-------+-------+
| 1 | 2019/03/16/2 | 8 | 2 |
+------------+--------------+-------+-------+
| 1 | 2019/03/16/1 | 3 | 0 |
+------------+--------------+-------+-------+
account_id is a primary partition key. record_id is a primary sort key
How I can get only latest records for each of the account_ids? So from the example above I expect to get:
+------------+--------------+-------+-------+
| account_id | record_id | views | stars |
+------------+--------------+-------+-------+
| 3 | 2019/03/16/1 | 29 | 3 |
+------------+--------------+-------+-------+
| 2 | 2019/03/16/2 | 130 | 21 |
+------------+--------------+-------+-------+
| 1 | 2019/03/16/3 | 12 | 2 |
+------------+--------------+-------+-------+
This data is convenient to use for a reporting purposes.
Execute the following PartiQL query for each account_id:
SELECT * FROM <Table> WHERE account_id='3' AND record_id > '2021/11' ORDER BY record_id DESC
PartiQL has no LIMIT keyword, so will return all matching records.
You can reduce overfetching by constraining the record_id date to the extent possible. If only the current date is of interest, for example, the sort key expression would be record_id > 2021/12/01.
As in the referenced example, you must execute one query for each account_id of interest. Batching operations are supported.
I've a data table like this
+------------+-------+
| Model | Price |
+------------+-------+
| Apple-1 | 10 |
+------------+-------+
| New Apple | 11 |
+------------+-------+
| Orange | 13 |
+------------+-------+
| Orange2019| 15 |
+------------+-------+
| Cat | 19 |
+------------+-------+
I'want to define a list of base model tags that I want to add to any single row that matches certain condition/value. So for example defined a data frame for tagging like this
+------------+--------+
| Model | Tag |
+------------+------ -+
| Apple-1 | A |
+------------+------ -+
| New Apple | A |
+------------+------ -+
| Orange | B |
+------------+------ -+
| Cat | B |
+------------+--------+
I would like to find some way to get this results:
+------------+-------+--------+
| Model | Price | Tag |
+------------+-------+--------+
| Apple-1 | 10 | A |
+------------+-------+--------|
| New Apple | 11 | A |
+------------+-------+--------|
| Orange | 13 | B |
+------------+-------+--------|
| Orange2019| 15 | B |
+------------+-------+--------|
| Cat | 19 | B |
+------------+-------+--------|
I'm don't mind to use a table to managed the tagging data, and I know that I could write very "ad-hoc" mutate statement to achieve the results I want, just wondering if there is more elegant way to tagging a string based on a pattern match.
One idea is to use the Levenshtein distances to cluster the words you have. You would need to provide with a number of clusters. Once you have this clusters, just add the number of each one as a category tag to your table. Check out this answer which goes into detail of Levenshtein distance clustering. Text clustering with Levenshtein distances
edit
I think I totally misunderstood your question... try this
df=data.frame("Model"=c("Apple-1","New Apple","Organe","Orange2019","Cat"),
"Price"=c(10,11,13,15,19),stringsAsFactors = FALSE)
tags=data.frame("Model"=c("Apple-1","New Apple","Orange","Cat"),
"Tag"=c("A","A","B","B"),stringsAsFactors = FALSE)
df%>%rowwise()%>%mutate(Tag=if_else(!is.na(tags$Tag[which(!is.na(str_extract(Model,tags$Model)))[1]]),
tags$Tag[which(!is.na(str_extract(Model,tags$Model)))[1]],false="None"))
Model Price Tag
<chr> <dbl> <chr>
1 Apple-1 10 A
2 New Apple 11 A
3 Organe 13 None
4 Orange2019 15 B
5 Cat 19 B
I actually changed Orange for Organe so that you see what happens if there is not match ( none is returned)
I have the following table in an sqlite database
+----+-------------+-------+
| ID | Week Number | Count |
+----+-------------+-------+
| 1 | 1 | 31 |
| 2 | 2 | 16 |
| 3 | 3 | 73 |
| 4 | 4 | 59 |
| 5 | 5 | 44 |
| 6 | 6 | 73 |
+----+-------------+-------+
I want to get the following table out. Where I get this weeks sales as one column and then the next column will be last weeks sales.
+-------------+-----------+-----------+
| Week Number | This_Week | Last_Week |
+-------------+-----------+-----------+
| 1 | 31 | null |
| 2 | 16 | 31 |
| 3 | 73 | 16 |
| 4 | 59 | 73 |
| 5 | 44 | 59 |
| 6 | 73 | 44 |
+-------------+-----------+-----------+
This is the select statement i was going to use:
select
id, week_number, count,
(select count from tempTable
where week_number = (week_number-1))
from
tempTable;
You are comparing values in two different rows. When you are just writing week_number, the database does not know which one you mean.
To refer to a column in a specific table, you have to prefix it with the table name: tempTable.week_number.
And if both tables have the same name, you have to rename at least one of them:
SELECT id,
week_number,
count AS This_Week,
(SELECT count
FROM tempTable AS T2
WHERE T2.week_number = tempTable.week_number - 1
) AS Last_Week
FROM tempTable;
In case of you want to take a query upon a same table twice, you have to put aliases on the original one and its replicated one to differentiate them
select a.week_number,a.count this_week,
(select b.count from tempTable b
where b.week_number=(a.week_number-1)) last_week
from tempTable a;
I am developing a survey application, a very simple one that has two tables.
table_survey_answers
+------------+------------+----------------+
| customerid | questionID | answer |
+------------+------------+----------------+
| 1 | 100 | Good |
| 1 | 101 | Acceptable |
| 1 | 102 | Excellent |
| 2 | 100 | Not acceptable |
| 2 | 101 | Acceptable |
| 2 | 102 | Good |
+------------+------------+----------------+
table_questions
+------------+-----------------------------------+
| QuestionID | Question |
+------------+-----------------------------------+
| 100 | Kindly rate our customer service? |
| 101 | How fast is our product delivery? |
| 102 | Quality of the Product A? |
+------------+-----------------------------------+
Now I want display survey result as follow in asp.net gridview.
+------------+-----------------------------------+-----------------------------------+---------------------------+
| CustomerID | Kindly rate our customer service? | How fast is our product delivery? | Quality of the Product A? |
+------------+-----------------------------------+-----------------------------------+---------------------------+
| 1 | Good | Acceptable | Excellent |
| 2 | Not Acceptable | acceptable | Good |
+------------+-----------------------------------+-----------------------------------+---------------------------+
I already created tables to get survey responses. Only thing I want export the result in gridview as explained above format.
Use Pivot which will transpose your rows to columns
SELECT *
FROM (SELECT customerid,
answer,
Question
FROM table_questions a
JOIN table_survey_answers b
ON a.QuestionID = b.questionID) a
PIVOT (Max(answer)
FOR Question IN([Kindly rate our customer service?],
[How fast is our product delivery?],
[Quality of the Product A?])) piv
SQL FIDDLE DEMO
I have thousands of rows of data, a segment of which looks like:
+-------------+-----------+-------+
| Customer ID | Company | Sales |
+-------------+-----------+-------+
| 45678293 | Sears | 45 |
| 01928573 | Walmart | 6 |
| 29385068 | Fortinoes | 2 |
| 49582015 | Walmart | 1 |
| 49582015 | Joe's | 1 |
| 19285740 | Target | 56 |
| 39506783 | Target | 4 |
| 39506783 | H&M | 4 |
+-------------+-----------+-------+
In every case that a customer ID occurs more than once, the value in 'Sales' is also the same but the value in 'Company' is different (this is true throughout the entire table). I need for each value in 'Customer ID to only appear once, so I need a single row for each customer ID.
In other words, I'd like for the above table to look like:
+-------------+-----------+-------+
| Customer ID | Company | Sales |
+-------------+-----------+-------+
| 45678293 | Sears | 45 |
| 01928573 | Walmart | 6 |
| 29385068 | Fortinoes | 2 |
| 49582015 | Walmart | 1 |
| 19285740 | Target | 56 |
| 39506783 | Target | 4 |
+-------------+-----------+-------+
If anyone knows how I can go about doing this, I'd much appreciate some help.
Thanks!
Well it would have been helpful, if you have put your sql generate that data.
but it might go something like;
SELECT customer_id, Max(Company) as company, Count(sales.*) From Customers <your joins and where clause> GROUP BY customer_id
Assumes; there are many company and picks out the most number of occurance and the sales data to be in a different table.
Hope this helps.