I have problems using jooq with kotlin and the any clause.
Given the following:
I have a Database field in a postgreSQL database which is an array
I have search parameters which are a List of Strings
I want to use jooq any operator to search in the array
I have the following code which is not working:
fun findAll(
someArrayListOfStrings: List<String>?
): List<SomeDTO> {
val filters = ArrayList<Condition>()
filters.add(TABLE.SOME_FIELD.eq(DSL.any(someArrayListOfStrings)))
}
Here I want to dynamically create filters (jooq Conditions) to be added to some SQL statement. It should work to look if SOME_FIELD (PostgreSQL Array Type) contains one of the following strings using the ANY clause (PostgreSQL jooq binding). However I get the following compile-time error:
None of the following functions can be called with the arguments supplied:
public abstract fun eq(p0: Array<(out) String!>!): Condition defined in org.jooq.TableField
public abstract fun eq(p0: Field<Array<(out) String!>!>!): Condition defined in org.jooq.TableField
public abstract fun eq(p0: QuantifiedSelect<out Record1<Array<(out) String!>!>!>!): Condition defined in org.jooq.TableField
public abstract fun eq(p0: Select<out Record1<Array<(out) String!>!>!>!): Condition defined in org.jooq.TableField
But my function call should match the third type where QuantifiedSelect is used.
I looked for hours on the internet but was not able to find any solution. Any site I found told me to try the solution I already have. Does anyone have an idea what I could try and why it does not work?
Thank you!
The method you're calling here is DSL.any(T...), which takes a generic varargs array (in Java). You're passing a List<String>, so this binds T = List<String>, which doesn't satisfy the type constraint on the eq() method.
But even if you changed that to an Array<String>, it wouldn't work because the jOOQ ANY operator doesn't do the exact same thing as the PostgreSQL any(array) operator. So, just resort to either plain SQL templating:
condition("{0} = any({1})", TABLE.SOME_FIELD,
DSL.value(someArrayListOfStrings.toTypedArray()))
Or just use the IN predicate
TABLE.SOME_FIELD.in(someArrayListOfStrings)
Related
I have a static 2 dimensional array of objects in a Kotlin project:
class Tables {
companion object{
lateinit var finalTable: Array<Array<Any?>?>
}
}
It is a little clearer in Java:
public class Tables {
public static Object[][] finalTable;
}
The third element in one row of objects in the table, is a string boxed as an object. In other words: finalTable[*][2] is a string describing the item. When I add an item to the array in Kotlin, I want to sort the entire array in alphabetical order of the description.
In Java this is easy:
Arrays.sort(Tables.finalTable, Comparator.comparing(o -> (String) o[2]));
When I try to use Android Studio to translate the Java code into Kotlin, it produces the following:
Arrays.sort( Tables.finalTable, Comparator.comparing( Function { o: Array<Any?>? -> o[2] as String }) )
This does not work, you have change the String cast as follows:
Arrays.sort( Tables.finalTable, Comparator.comparing( Function { o: Array<Any?>? -> o[2].toString() }) )
This version will compile and run, but it totally messes up the sorting of the table, so it does not work. I have tried variations on this theme, without any success. To get my project to work, I had to create a Java class in the Kotlin project with the functional Java code listed above:
public class ArraySort {
public void sortArray(){
Arrays.sort(Tables.finalTable, Comparator.comparing(o -> (String) o[2]));
}
}
This sorts the table like a charm, but I would prefer to keep my project "pure Kotlin". Can anyone suggest a pure Kotlin method to sort such an array? Thanks!
Unless I'm missing something, you can just do this:
Tables.finalTable.sortBy { it[2] as String }
which sorts your array in place. sortedBy will produce a new copy of the original if that's what you want instead, and might be why the comment suggestions weren't working for you.
But this whole unstructured array situation isn't ideal, the solution is brittle because it would be easy to put the wrong type in that position for a row, or have a row without enough elements, etc. Creating a data structure (e.g. a data class) would allow you to have named parameters you can refer to (making the whole thing safer and more readable) and give you type checking too
I extracted from a previous response an Object of tuple with the following regex :
.check(regex(""""idSc":(.{1,8}),"pasTemps":."codePasTemps":(.),"""").ofType[(String,String)].findAll.saveAs ("OBJECTS1"))
So I get my object :
OBJECTS1 -> List((1657751,2), (1658105,2), (4557378,2), (1657750,1), (916,1), (917,2), (1658068,1), (1658069,2), (4557379,2), (1658082,1), (4557367,1), (4557368,1), (1660865,2), (1660866,2), (1658122,1), (921,1), (922,2), (923,2), (1660875,1), (1660876,2), (1660877,2), (1658300,1), (1658301,1), (1658302,1), (1658309,1), (1658310,1), (2996562,1), (4638455,1))
After that I did a Foreach and need to extract every couple to add them in next requests So we tried :
.foreach("${OBJECTS1}", "couple") {
exec(http("request_foreach47"
.get("/ctr/web/api/seriegraph/bydates/${couple(0)}/${couple(1)}/1552863600000/1554191743799")
.headers(headers_27))
}
But I get the message : named 'couple' does not support index access
I also though that to use 2 regex on the couple to extract both part could work but I haven't found any way to use a regex on a session variable. (Even if its not needed for this case but possible im really interessed to learn how as it could be usefull)
If would be really thankfull if you could provided me help. (Im using Gatling 2 but can,'t use a more recent version as its for work and others scripts have been develloped with Gatling2)
each "couple" is a scala tuple which can't be indexed into like a collection. Fortunately the gatling EL has a function that handles tuples.
so instead of
.get("/ctr/web/api/seriegraph/bydates/${couple(0)}/${couple(1)}/1552863600000/1554191743799")
you can use
.get("/ctr/web/api/seriegraph/bydates/${couple._1}/${couple._2}/1552863600000/1554191743799")
In my Kotlin Android project, I made a FileItem class which extends Serializable
class FileItem(<parameters>) : Serializable, Comparable<FileItem> {
So I needed to Serialize instances of this class into a Bundle
val arguments:Bundle = Bundle()
arguments.putSerializable("folders", folders as Serializable)
where folders has been declared as :
folders:Array<FileItem> (method parameter)
The serialization code above compile without any warning. Meanwhile, the problem comes when I need to unserialize folders items :
val arguments: Bundle? = getArguments()
if (arguments != null){
foldersItems = arguments.getSerializable("folders") as Array<FileItem>
where foldersItems is declared as
var foldersItems: Array<FileItem>?
I get the following warning, that I can't manage to solve without suppress_warning annotation :
w: <Path to my class>: (78, 28): Unchecked cast: java.io.Serializable! to kotlin.Array<com.loloof64.android.chess_positions_archiver.main_file_explorer.FileItem>
This kind of code compiles in Java/Groovy without warning (folderItems is then a FileItem[]), so how can I modify the kotlin code for the compiler to be "satisfied" ?
I noticed in official Kotlin documentation that Kotlin Array does not extend Serializable and is not open for inheritance. Is it possible meanwhite to "add" it via a kind of extension method ?
In fact, the cast is not unchecked, the compiler's warning is misleading.
This happens because in Kotlin arrays are represented by generic class Array<T>, and the compiler treats it as usual generic class with type parameters erased at runtime.
But on JVM arrays have reified types, and when you cast something as Array<SomeType>, the generated bytecode really checks the type parameter to be SomeType as well as something being an Array<*>, which would only happen for any other generic class.
This example shows that the array cast is checked:
val a: Any = Array<Int>(1) { 0 }
val i = a as Array<Int>
val d = a as Array<Double> // gets checked and throws ClassCastException
The easiest solution is indeed to #Suppress("UNCHECKED_CAST"), because actually there should not be any warning.
I filed an issue describing the problem in Kotlin issue tracker.
The cast here is unchecked because the compiler here can't ensure the nullability of array's generic type parameter.
Consider the following example:
fun castAsArrayOfString(param: Any) = param as Array<String>
castAsArrayOfString(arrayOf("a")) // is Array<String>, all ok
castAsArrayOfString(arrayOf("a", null)) // is Array<String>, but contains null
So the compiler warns you about potential type safety problems this cast could introduce.
I'm using GNAT GPS studio IDE in order to train a bit in Ada. I'm having an issue with package visibility.
First I specify a package in a file called "DScale.ads" containing a type:
package DScale is
type DMajor is (D, E, F_Sharp, G, A, B, C_Sharp);
end DScale;
Then I specify in a different file ("Noteworthy.ads") a package that defines a procedure that will use the DMajor type of the DScale package:
with Ada.Text_IO;
with DScale;
package NoteWorthy is
procedure Note;
end NoteWorthy;
Finally in "Noteworthy.adb" I provide the package body for the package "Noteworthy":
with Ada.Text_IO; use Ada.Text_IO;
package body Noteworthy is
procedure Note is
package ScaleIO is new Enumeration_IO(DScale.DMajor);
thisNote : DScale.DMajor := DScale.D;
begin
ScaleIO.Get(thisNote);
if thisNote = DScale.DMajor'First then
Put_Line("First note of scale.");
end if;
end Note;
begin
null;
end NoteWorthy;
If I leave the code as-is, I will get an "operator not directly visible" error for the "if thisNote = DScale.DMajor'First then" statement in the body of the "Noteworthy" package.
Is there a way to bypass this error without using a "use" or "use type" clause?
Thank you.
There are (at least) two answers to your question.
1:
if DScale."=" (thisNote, DScale.DMajor'First) then
2:
function "=" (Left, Right : DScale.DMajor) return Boolean renames DScale.DMajor;
...
if thisNote = DScale.DMajor'First then
But why would you use one of those options instead of:
use type DScale.DMajor;
...
if thisNote = DScale.DMajor'First then
Ada types are much more than just descriptions of the values, they are entities that bring into existence a whole slew of operations, embodied as both operators and attributes. So if you want direct visibility to a type's concrete "=" operator, you have to make it visible. For that you need either "use" or "use type".
Why bypass a language feature? Simply use it wisely.
A couple of points that are related to the structure of your code.
The package spec for Noteworthy doesn't need to "with DScale" as there is nothing in the spec that refers to any feature in that package (maybe you plan to in the future).
The use of enumeration_io is good if you want to simply want to do I/O to files to be read by a computer, but I would never use it for human interaction (apart from quick hacks). The input values it accepts is dictated by Ada's grammar, and typically not what user's expect.
I'm using NHibernate 2.1.2.4000GA. I'm trying to use SQL Server's CONTAINS function from within HQL and the criteria APIs. This works fine in HQL:
CONTAINS(:value)
However, I need to qualify the table in question. This works fine:
CONTAINS(table.Column, :value)
However, I need to search across all indexed columns in my table. I tried this:
CONTAINS(table.*, :value)
But I get:
NHibernate.Hql.Ast.ANTLR.QuerySyntaxException : Exception of type 'Antlr.Runtime.MissingTokenException' was thrown. near line ... [select table.Id from Entities.Table table where CONTAINS(table.*,:p0) order by table.Id asc]
at NHibernate.Hql.Ast.ANTLR.ErrorCounter.ThrowQueryException()
at NHibernate.Hql.Ast.ANTLR.HqlParseEngine.Parse()
at NHibernate.Hql.Ast.ANTLR.QueryTranslatorImpl.Parse(Boolean isFilter)
at NHibernate.Hql.Ast.ANTLR.QueryTranslatorImpl.DoCompile(IDictionary`2 replacements, Boolean shallow, String collectionRole)
at NHibernate.Hql.Ast.ANTLR.QueryTranslatorImpl.Compile(IDictionary`2 replacements, Boolean shallow)
at NHibernate.Engine.Query.HQLQueryPlan..ctor(String hql, String collectionRole, Boolean shallow, IDictionary`2 enabledFilters, ISessionFactoryImplementor factory)
at NHibernate.Engine.Query.QueryPlanCache.GetHQLQueryPlan(String queryString, Boolean shallow, IDictionary`2 enabledFilters)
at NHibernate.Impl.AbstractSessionImpl.GetHQLQueryPlan(String query, Boolean shallow)
at NHibernate.Impl.AbstractSessionImpl.CreateQuery(String queryString)
So it would seem the HQL parser chokes on the asterisk. I thought of doing this:
CONTAINS(table.Column1, :value) or CONTAINS(table.Column2, :value)
Not only is this inefficient, it can also yields incorrect results depending on the full text predicate in :value.
I tried customizing my dialect as per these instructions, but that doesn't help because you're still left with the same problem: specifying table.* causes the HQL parser to fall over.
I thought of specifying query substitutions:
<property name="query.substitutions">TABLECONTAINS(=CONTAINS(table.*,</property>
And then simply doing:
TABLECONTAINS(:value)
But that does not work. I'm not sure why - judging by the resultant error, the substitution just doesn't take place because "TABLECONTAINS" is still present in the query. Besides, this wouldn't work for all cases because I'd need to know the alias of the table and dynamically substitute it in.
Therefore, I rolled an interception-based approach:
using System;
using NHibernate;
using NHibernate.SqlCommand;
public class ContainsInterceptor : EmptyInterceptor
{
public override SqlString OnPrepareStatement(SqlString sql)
{
var indexOfTableContains = sql.IndexOfCaseInsensitive("TABLECONTAINS(");
if (indexOfTableContains != -1)
{
var sqlPart = sql.ToString();
var aliasIndex = sqlPart.LastIndexOf("Table ", indexOfTableContains, StringComparison.Ordinal);
if (aliasIndex == -1)
{
return sql;
}
aliasIndex += "Table ".Length;
var alias = sqlPart.Substring(aliasIndex, sqlPart.IndexOf(" ", aliasIndex, StringComparison.Ordinal) - aliasIndex);
sql = sql.Replace("TABLECONTAINS(", "CONTAINS(" + alias + ".*,");
}
return base.OnPrepareStatement(sql);
}
}
This works and I will now be able to sleep tonight, but I do feel a sudden desire to attend London's impending papal procession and shout out a confession.
Can anyone suggest a better way to achieve this?
Why not use an ISQLQuery instead?
You can still retrieve entities, see http://nhibernate.info/doc/nh/en/index.html#querysql-creating
I would think that a custom dialect would be the appropriate way to handle this. You can find some guidance in this article. I've used this approach to register SQL Server-specific functions like ISNULL for use in our projects.