t:([] col1:`aa`bb`cc;col2:`aaa`bbb`ccc);
field1:`col1;
field2:`col2;
v1:`aa;
v2:`aaaa;
I want same result by functional update as
update col2:`aaaa from t where col1=`aa;
I tried
![t;enlist (=;field1;enlist v1);0b;(enlist field2)!(enlist v2)];
but it give me an error 'aaaa
appreciate if some one can help.
![t;enlist (=;field1;enlist v1);0b;(enlist field2)!(enlist enlist v2)]
You can use the parse function to convert the update expression to a parse tree from which you can easily read off the proper arguments for the functional update.
q)parse"update col2:`aaaa from t where col1=`aa"
!
`t
,,(=;`col1;,`aa)
0b
(,`col2)!,,`aaaa
Recall that unary , is enlist, so the functional form of your query would be
![t;enlist(=;`col1;enlist `aa);0b;(enlist `col2)!enlist enlist `aaaa]
or, using variable names,
![t;enlist(=;field1;enlist v1);0b;(enlist field2)!(enlist enlist v2)]
It's not in functional update form, but here's another way you can updated your table
#[t; where t[`col1] =`aa; :; enlist[`col1]!enlist[`aaaa]]
Related
How does one define constraints via Vapor? Here's my latest attempt:
database.schema(Thingmabob.schema)
.id()
.field("parentID", .uuid, .required, .references(Stuff.schema, .id))
.field("name", .string, .required)
.field("isDocumened", .bool, .required)
.field("value1", .uint, .required)
.field("value2", .uint)
.constraint(.custom("value2 > value1 + 1")) // << "syntax error"
.create()
Solution is two folds:
1) Seems the documentation — HA! — forgot to mention that any field mentionned in the .constraint(.custom( ... )) is set to lowercase. So if you have a field/column like .constraint(.custom("isDocumented ..."), the value in the constraint becomes isdocumented which fails to matches any column. Just beautiful!
2) Also, note that, while I'm using the .constraint() API, the framework has no idea what do to with it... I thus have to write the full statement CHECK notcamelcase > alsonotcamelcase (not just notcamelcase > alsonotcamelcase). Not sure why .constraint() isn't named .arbitrarySQLSegment() as that would've been more accurate and helpful than all that documentation I've read.
zsh version 5.2
I'm attempting an array assignment using filename generation like so:
files=(/some/path/*/dir/myfile)
Indeed this is the way the zshoptions manual recommends to achieve what I want.
When no matches exist I want the array to be empty. Instead it's producing
no matches found: /some/path/*/dir/file
and the script terminates.
I've tried setting NULL_GLOB, CSH_NULL_GLOB and ensured NOMATCH is not set.
When matches do exist it works as expected.
Any help is appreciated.
Thank you in advance,
Wayne
Well of course I found the solution after posting my question.
For this to work EXTENDED_GLOB needs to be set as well as NULL_GLOB. Or a glob qualifier can be used so that NULL_GLOB only effects this particular expansion.
This is how to set NULL_GLOB for a single operation:
files=(/some/path/*/dir/myfile(N))
Hope that can help someone else who encounters this.
Wayne
I have a unit test for a function that adds data (untransformed) to the database. The data to insert is given to the create function.
Do I use the input data in my asserts or is it better to specify the data that I’m asserting?
For eample:
$personRequest = [
'name'=>'John',
'age'=>21,
];
$id = savePerson($personRequest);
$personFromDb = getPersonById($id);
$this->assertEquals($personRequest['name'], $personFromDb['name']);
$this->assertEquals($personRequest['age'], $personFromDb['age']);
Or
$id = savePerson([
'name'=>'John',
'age'=>21,
]);
$personFromDb = getPersonById($id);
$this->assertEquals('John', $personFromDb['name']);
$this->assertEquals(21, $personFromDb['age']);
I think 1st option is better. Your input data may change in future and if you go by 2nd option, you will have to change assertion data everytime.
2nd option is useful, when your output is going to be same irrespective of your input data.
I got an answer from Adam Wathan by e-mail. (i took his test driven laravel course and noticed he uses the 'specify' option)
I think it's just personal preference, I like to be able to visually
skim and see "ok this specific string appears here in the output and
here in the input", vs. trying to avoid duplication by storing things
in variables." Nothing wrong with either approach in my opinion!
So i can't choose a correct answer.
Blasphemy I know to ask IF it is possible to do something in R, but here I am!
I am interested in the ability to create a function that will place code into the console. In other words, if the user types in f("3+3") and hits enter then the console will be waiting for the next command with > 3+3. Then when the user hits enter, it will return 6 in this case. Possible? Any ideas?
I wish I had more to share but I've never even thought this functionality would be useful before...
One way you could do this is to call system2() to invoke an external utility that synthesizes keyboard input. I've written a C++ program called sendkeys that can do this on Windows by (ultimately) calling SendInput(). Demo:
system2('sendkeys','3\\\\+3');
3+3
## [1] 6
(The backslash escaping is necessary because of the way my utility parses its input; + is a metachar that must be escaped to become literal.)
Let me know if you want my C++ code.
Would that be the kind of function you would need? Maybe it is not a very elegant solution, though.
printEval <- function(x){
cat(">", x,"\n")
cat ("Press [enter] to continue")
line <- readline()
eval(parse(text=x))
}
EDIT: Sorry, I just noticed that the eval(parse()) solution was already suggest by #Ping in the comment field right under the question.
I have an entry level question which my book could not help with and I also confused a colleague. Can I use RDF without specifiying prefixes and how do I specificy the predicate in the SPARQL query?
I'm doing this in R's RRDF package but if I set up a store as
A=new.rdf(ontology=F)
add.triple(A,"Ian","sonOf","Daddy")
add.triple(A,"Ian","sonOf","Mummy")
add.triple(A,"Ian","likes","Chocolate")
I get the following message
## Error: com.hp.hpl.jena.query.QueryParseException: Lexical error
at line 1, column 40. Encountered: " " (32), after : "sonOf"
to the query
sparql.rdf(A, "select ?son ?parent where {?son sonOf ?parent}")
Can I use sonOf in this way? Do I have to set up my own Schema first? Am I doing something fundamentally wrong? Do I have to use prefixes if all my data resides on the same data source?
An RDF predicate is always a URI (technically, actually a IRI, but let's set that aside).
It can be specified as a prefixed name:
namespace:sonOf
or an IRIRef, e.g:
<http://my.namespace.com#sonOf>
but I don't think it can be given as a plain label like you are attempting.
If you use the prefixed name style, then the prefix must be defined and bound to a namespace, so that a valid URI can be constructed from your input.
(The formal grammar is given in the SPARQL Specification.)
In the rrdf R package, the following syntax seemed to work:
library(rrdf)
D = new.rdf(ontology = F)
add.triple(D, "ian", "w:likes", "food")
add.triple(D, "ian", "w:hates", "homework")
sparql.rdf(D, "select ?child ?object where {?child <w:likes> ?object.}")
sparql.rdf(D, "select ?child ?object where {?child <w:hates> ?object.}")
You thus need to used the <> in the SPARQL calls but not calls to add.triple(). This seems obvious now but confused a few of us at the time.
i think you're asking about "blank" prefixes... if so:
when you define your prefixes, you can just say something like:
PREFIX : <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
which would then be used like:
?sub :sonOf ?obj