Here I have a scala UDF that checks if a url is one of my domains. To check if 'to_site' is one of my domains, I'm using indexOf in javascript.
CREATE TEMPORARY FUNCTION our_domain(to_site STRING)
RETURNS BOOLEAN
LANGUAGE js AS """
domains = ['abc.com', 'xyz.com'];
if (to_site == null || to_site == undefined) return false;
for (var i = 0; i < domains.length; i++){
var q= DOMAIN('XYZ');
if (String.prototype.toLowerCase.call(to_site).indexOf(domains[i]) !== -1)
return true;
}
return false;
""";
SELECT our_domain('www.foobar.com'), our_domain('www.xyz.com');
This returns false, then true.
It would be much nicer if I could use the DOMAIN(url) function from javascript. indexOf is not very good because it will match www.example.com?from=www.abc.com, when actually example.com is not one of my domains. Javascript also has a (new URL('www.example.com/q/z')).hostname to parse the domain component, but it includes the subdomain like 'www.' which complicates the comparison. Bigquery's DOMAIN(url) function only gives the domain and knowing google it's fast C++.
I know I can do this
our_domain(DOMAIN('www.xyz.com'))
But in general it would be nice to use some of the bigquery API functions in javascript. Is this possible?
I also tried this
CREATE TEMPORARY FUNCTION our_domain1(to_site String)
AS (our_domain(DOMAIN(to_site));
but it fails saying DOMAIN does not exist.
DOMAIN() function is supported in BigQuery Legacy SQL whereas Scalar UDFs are part of BigQuery Standard SQL.
So, unfortunatelly, no, you cannot use DOMAIN() function with code that uses Scalar UDF as of now at least.
And, no, you cannot use SQL Functions within JS [Scalar] UDFs, but you can use them in SQL UDFs
Finally, as I suggested in my answer on your previous question - in somple scenario like this your particular one - you better use SQL Scalar SQL vs. JS Scalar UDFs - they do not have LIMITs that JS UDFs have
The DOMAIN function in legacy SQL is more or less just a regular expression. Have you seen this previous question about DOMAIN? As Mikhail points out, you should be able to define a SQL UDF that uses a regex to extract the domain and then checks if it's in your list.
Related
A python library for SQL that I've used provided sanitation of query parameters to protect against injection attacks if you used the ('query == $0', param) approach, but not if you created the string yourself, i.e. ('query == param'). Is this the same in Realm for React Native?
Is there any functional difference between results.filtered(`query == ${param}`) and results.filtered('query == $0', param) ?
Yes, those are different, and filtered('query == $0', param) will work regardless of the contents of param, while filtered(`query == ${param}`) will not.
The substitution parameter syntax does not sanitize the input per se. The interface for the low-level query engine isn't string-based, so unlike with an SQL library there never is a query string with the parameters substituted in involved at all, so there isn't actually any sanitization needed. The end result is largely the same, though.
Is there any way to call a function or a variable within a realm query such as this? The _getDate() function can't seem to be called within the filtered
realm.objects('Round').filtered('id !== {_getDate()}')
Can you try the following code? Use string template syntax (Backtick instead quote and ${_getDate()}.) Also, Realm's query syntax is not same as JavaScript. It doesn't have !== operator. Use !=.
realm.objects('Round').filtered(`id != ${_getDate()}`)
I cannot figure out how to return JSONP in RestXQ. After adding
let $x := util:declare-option("exist:serialize", fn:concat("method=json jsonp=",request:get-parameter("callback", "callback")))
to the function, I get the error message:
err:XPTY0004:It is a type error if, during the static analysis phase, an expression is found to have a static type that is not appropriate for the context in which the expression occurs, or during the dynamic evaluation phase, the dynamic type of a value does not match a required type as specified by the matching rules in 2.5.4 SequenceType Matching.
The beginning of the GET function is:
declare
%rest:GET
%rest:path("/demo/contacts/submit")
%rest:query-param("email", "{$email}", '')
%rest:query-param("nomail", "{$nomail}", 0)
%rest:produces("application/javascript")
%output:media-type("application/javascript")
%output:method("json")
function contacts:submit($email as xs:string*, $nomail as xs:integer*)
{
try
{
let $x := util:declare-option("exist:serialize", fn:concat("method=json jsonp=",request:get-parameter("callback", "callback")))
As discussed on the eXist-open mailing list (I'd suggest joining!), the request module's get-parameter() function is not available inside a RestXQ function. Instead, you can get your callback parameter via the %rest:query-param annotation. Add %rest:query-param("callback", "{$callback}", '') to your contacts:submit() function, and I think you'll be a step closer.
#joewiz is correct. Your initial problem is related to the use of eXist request module from RESTXQ, which is unsupported.
Also, RESTXQ does not currently support JSONP serialization. If you want to use JSONP serialization, your best bet at the moment is to manage the serialization to JSON yourself, perhaps using the xqjson library or similar and then wrapping the result in a JSON function using concat or similar.
This is probably fairly straightforward but i can't seem to find a reasonable explanation in any documentation.
I'm trying to use an NHibernate.ISQLQuery and using SetResultTransformer() to return a custom set of results from a custom SQL query. Like so:
public virtual IList<T> GetSQLObject<T>(string sql, IDbParameter[] parameters = null)
{
ISQLQuery qry = _sess.CreateSQLQuery(sql);
qry.SetResultTransformer(Transformers.AliasToBean(typeof(T)));
if (parameters != null) {
foreach (IDbParameter parameter in parameters) {
qry.SetParameter(parameter.Name, parameter.Value);
}
}
return qry.List<T>();
}
From looking at the examples, it seems that in the sql query I have to use parameters in the format :param1 instead of #param1 as I would in a standard SQL query. If i use the latter syntax in the query, it throws an error at qry.SetParameter().
Is there a reason why ISQLQuery/NHibernate requires them in this format and won't work with the normal syntax?
SQL Server uses #param, but not every other database does. For example, MySQL uses ?param
NHibernate allows you to swap out 1 database implementation for another with little to no reworking of your DAL. It sets the parameters based on the database you configured when you setup the NH Configuration.
Edit: Also I think :param came about from Hibernate being targeted at Oracle when it was initially developed, since Oracle uses :param
Phil has answered the "why"; so perhaps I can recommend a "how"; why not just add a new extension method to the IDbParameter type (something like .GetNHibernateName() ) that will return the parameter name with the "#" replaced with a ":"; that should be trivial to implement.
Is it possible to calculate Standard Deviation with NHibernate? I'm using the Microsoft SQL Server 2005 Dialect.
I can't find any examples of this anywhere.
Please help.
thanks!
Just wanted to let everyone know how I accomplished this with code that may help others:
When I create my SessionFactory, I simply add a custom SQL Function to the Configuration Object:
Setup:
var configuration = new Configuration();
configuration.AddSqlFunction("stdev", new StandardSQLFunction("stdev", HibernateUtil.Double));
SessionFactory = configuration.Configure().BuildSessionFactory();
Usage:
Then in my data provider I now can call the custom function:
ICriteria criteria = _session.CreateCriteria(typeof(ItemHistory));
criteria.SetProjection(Projections.SqlFunction("stdev", NHibernateUtil.Double, Projections.Property("Speed") ));
IList results = criteria.List();
I'm not that familiar with NHibernate, but using the Java Hibernate you can subclass an existing dialect easily to add extra functions. Something like this might do the trick for you (this is the Java version):
public class MyDialect extends SQLServerDialect
{
public MyDialect()
{
super();
// register extra functions (may need to specify parameter types)
registerFunction( "stdev", new StandardSQLFunction( "stdev" ) );
}
}
STDEV is a native SQL function for SQL Server... can you pass through a native query?
You can use native SQL queries, including aggregate functions, in HQL (Hibernate Query Language). See Chapter 12 in the documentation.
Edited to add: I just read it myself and STDEV is not supported. An alternative that might work is to create a view that includes the calculation and map the view instead of the table. Further Googling leads me to believe that the documentation may be out of date or there are extensions to NHibernate that include STDEV.
I've solved in a more standard way by this code:
sqrt((sum(value*value)/count(value)) - (avg(value) * avg(value)))
In other way, unrolling the formula of the standard deviation using the other aggregate functions that are supported: sum and count.
I've checked against the formula 'std()' in mysql and this works except by the least significant digits (error less of 0.000000001D).