I'm currently writing an app that accesses google bigquery via their "#google-cloud/bigquery": "^2.0.6" library. In one of my queries I have a where clause where i need to pass a list of ids. If I use UNNEST like in their example and pass an array of strings, it works fine.
https://cloud.google.com/bigquery/docs/parameterized-queries
However, I have found that UNNEST can be really slow and just want to use IN on its own and pass in a string list of ids. No matter what format of string list I send, the query returns null results. I think this is because of the way they convert parameters in order to avoid sql injection. I have to use a parameter because I, myself want to avoid SQL injection attacks on my app. If i pass just one id it works fine, but if i pass a list it blows up so I figure it has something to do with formatting, but I know my format is correct in terms of what IN would normally expect i.e. IN ('', '')
Has anyone been able to just pass a param to IN and have it work? i.e. IN (#idParam)?
We declare params like this at the beginning of the script:
DECLARE var_country_ids ARRAY<INT64> DEFAULT [1,2,3];
and use like this:
WHERE if(var_country_ids is not null,p.country_id IN UNNEST(var_country_ids),true) AND ...
as you see we let NULL and array notation as well. We don't see issues with speed.
Related
Well, I know this seems to be possible I just don't know how. To begin with, I am using traditional operators (without #task decorator) but I am interested in XComArgs return output format from these operators that can be used in downstream tasks. Below is a sample example
task_1 = DummyOperator(
task_id = 'task_1'
) # returns {"data": {"foo" : [{"cmd": "ls"}]}}
task_2 = BashOperator(
task_2='task_2',
cmd=task_1.output['return_value']['data']['foo'][0]['cmd'] # does not give what I need and returns null.
#cmd = f"{{ ti.xcom_pull(task_ids = 'task_1', key='return_value')['data']['foo'][0]['cmd'] }}" Gives what I need
)
In this example what is working for me which is pure Jinja templating and the new syntax does not work for me using XComArgs. I have tried changing the argument render_template_as_native_obj=True in Dag configuration but does not change anything. I want to use .output format which returns XcomArgs object and is returning the complete dict but have not been able to use the nested keys like above. Also, have tried converting string to JSON and all those combinations but does not seem to work.
Unfortunately, retrieving nested values from XComArgs in a limitation of the TaskFlow API.
The TaskFlow API uses __getitem__ to override the XCom key to use. In your example, the key ends up being "cmd" rather than the value of what cmd represents in that nested object. You'll have to use the original ti.xcom_pull() method until that limitation is addressed.
I want to use result set of meta-function get_node_dependencies as a subquery. Is there some way to do it?
Something like this:
select v_txtindex.StringTokenizerDelim (dep, chr(10)) over () as words
from (
select get_node_dependencies() as dep
) t;
This query thows an error Meta-function ("get_node_dependencies") can be used only in the Select clause.
I know that there is a view vs_node_dependencies that returns the same data in more readable way, but the question is generic, not related to any specific meta-function.
Most Vertica meta functions returning a report are for informational purposes on the fly, and can only be used on the outmost part of a query - so you can't apply another function on their output.
But - as you are already prepared to go through development work to split that output into tokens, you might often be even better off by querying vs_node_dependencies directly. You'll also be more flexible - is my take on this.
I'm using the ML9 Java API to upload a search options file to the DB with a name that I can use later in my search call. I would now like to write an xquery transform to highlight the query-matches in a set of elements in the response. Standard snippets won't work for me since they only bring back the fields in which there are matches and because they may not bring back the complete field value, but only the immediate context of the match.
So I want to use the cts:highlight function in a custom transform and want to pass to it the name of the options that I have uploaded into the DB. My question is how I can best get the options element from the DB using the name passed in to the transform method. I want to use this to construct the cts:query that I can pass in to the cts:highlight call as in:
let $query := cts:query(search:parse($query-string, $options))
let $result := cts:highlight($doc, $query, <markup>{$cts:text}
</markup>)
I was thinking I could pass in the query-string and the name of the pre-loaded options and use these to construct the cts:query, but don't know how to get the options from the name.
I found a way to avoid having to read the options. Setting the option 'return-query' to true adds a search:query node to the search:response which is passed to the transform method as the document-node. I'm then able to get this directly in the transform method to use in cts:highlight as:
let $query := cts:query($response/search:response/search:query/*[1])
The options are stored in the modules database associated with your REST instance. You could theoretically dig them out, though that would be relying on an implementation detail (the URI).
You might look into a combination of extract-document-data, as Sam mentioned, plus a search result transform, rather than the heavier approach of doing your own search through what I'd guess is a read transform.
Another alternative might be a custom snippeter that you pull into your options via transform-results. See http://docs.marklogic.com/guide/search-dev/query-options#id_58295.
Is it possible to apply a function like LookUpRows or Lookup to an array created with BuildRowSetFromString?
I have this:
SET #rowSet = BuildRowSetFromString(#ItemsString2, '|')
I'd like to know if there's a function on which I can do:
SET #var = LookupRows(#rowSet, ITEM_ID, ... )
I am trying already using a FOR loop. I want to know if there's a function that can do this.
No. I wish.
Best bet would be to use arrays in Server-Side JavaScript or possibly GTL.
If you want to over-engineer it, you can use XML and XPATH to do some array functions in AMPScript. I've written up a use-case with examples here on my personal blog.
Also, there is a lot more SFMC dicussion going on over in http://salesforce.stackexchange.com.
I'm writing a REST api in node js that will execute a sql query and send the results;
in the request I need to send the WHERE conditions; ex:
GET 127.0.0.1:5007/users //gets the list of users
GET 127.0.0.1:5007/users
id = 1 //gets the user with id 1
Right now the conditions are passed from the client to the rest api in the request's headers.
In the API I'm using sequelize, an ORM that needs to receive WHERE conditions in a particular form (an object); ex: having the condition:
(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)
this needs to be formatted as a nested object:
-- x=1
-- AND -| -- y=2
| -- OR ----|
| -- z=3
-- OR -|
|
| -- x=3
-- AND -|
-- y=1
so the object would be:
Sequelize.or (
Sequelize.and (
{x=1},
Sequelize.or(
{y=2},
{z=3}
)
),
Sequelize.and (
{x=3},
{y=1}
)
)
Now I'm trying to pass a simple string (like "(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)"), but then I will need a function on the server that can convert the string in the needed object (this method in my opinion has the advantage that the developer writing the client, can pass the where conditions in a simple way, like using sql, and this method is also indipendent from the used ORM, with no need to change the client if we need to change the server or use a different ORM);
The function to read and convert the conditions' string into an object is giving me headache (I'm trying to write one without success, so if you have some examples about how to do something like this...)
What I would like to get is a route capable of executing almost any kind of sql query and give the results:
now I have a different route for everything:
127.0.0.1:5007/users //to get all users
127.0.0.1:5007/users/1 //to get a single user
127.0.0.1:5007/lastusers //to get user registered in the last month
and so on for the other tables i need to query (one route for every kind of request I need in the client);
instead I would like to have only one route, something like:
127.0.0.1:5007/request
(when calling this route I will pass the table name and the conditions' string)
Do you think this solution would be a good solution or you generally use other ways to handle this kind of things?
Do you have any idea on how to write a function to convert the conditions' string into the desired object?
Any suggestion would be appreciated ;)
I would strongly advise you not to expose any part of your database model to your clients. Doing so means you can't change anything you expose without the risk of breaking the clients. One suggestion as far as what you've supplied is that you can and should use query parameters to cut down on the number of endpoints you've got.
GET /users //to get all users
GET /users?registeredInPastDays=30 //to get user registered in the last month
GET /users/1 //to get a single user
Obviously "registeredInPastDays" should be renamed to something less clumsy .. it's just an example.
As far as the conditions string, there ought to be plenty of parsers available online. The grammar looks very straightforward.
IMHO the main disadvantage of your solution is that you are creating just another API for quering data. Why create sthm from scratch if it is already created? You should use existing mature query API and focus on your business logic rather then inventing sthm new.
For example, you can take query syntax from Odata. Many people have been developing that standard for a long time. They have already considered different use cases and obstacles for query API.
Resources are located with a URI. You can use or mix three ways to address them:
Hierarchically with a sequence of path segments:
/users/john/posts/4711
Non hierarchically with query parameters:
/users/john/posts?minVotes=10&minViews=1000&tags=java
With matrix parameters which affect only one path segment:
/users;country=ukraine/posts
This is normally sufficient enough but it has limitations like the maximum length. In your case a problem is that you can't easily describe and and or conjunctions with query parameters. But you can use a custom or standard query syntax. For instance if you want to find all cars or vehicles from Ford except the Capri with a price between $10000 and $20000 Google uses the search parameter
q=cars+OR+vehicles+%22ford%22+-capri+%2410000..%2420000
(the %22 is a escaped ", the %24 a escaped $).
If this does not work for your case and you want to pass data outside of the URI the format is just a matter of your taste. Adding a custom header like X-Filter may be a valid approach. I would tend to use a POST. Although you just want to query data this is still RESTful if you treat your request as the creation of a search result resource:
POST /search HTTP/1.1
your query-data
Your server should return the newly created resource in the Location header:
HTTP/1.1 201 Created
Location: /search/3
The result can still be cached and you can bookmark it or send the link. The downside is that you need an additional POST.