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Questions tagged [mapper]

The mapper is the first step in MapReduce framework, a component of a larger scalable, parallel-izable algorithm.

Maps input key/value pairs to a set of intermediate key/value pairs.

Maps are the individual tasks which transform input records into a intermediate records. The transformed intermediate records need not be of the same type as the input records. A given input pair may map to zero or many output pairs.

The most common map reduce framework is Apache Hadoop.

See also MapReduce Wiki.

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Zend Framework - ORM relationships and optimization

I've been using ZF for few months and I'm really happy with it however I'm not completely sure about how to work with models relationships and at the same time avoid multiple queries to the db. Many people has this problem and no one seems to find a…
FranStrentz
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Liftweb - Maximum value of a SQL table field with mapper

I would like to find a simple way to access the maximum value of a Mapped element in liftweb, here is an example of what I actually do: Mapper part class MappedEntity extends LongKeyedMapper[MappedEntity] with IdPK { def getSingleton =…
Christopher Chiche
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How to create multiple database connection in scala / lift?

I want to configure my application to send & receive data from more than one DB. How do I configure my scala-lift application to do that ?
vkantiya
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why does MappedStringIndex not included in fieldList in Mapper

In Mapper's having String as a primary Key, why is the MappedStringIndex not shown in the list of all fields that are obtained via the Mapper's allFields method My Mapper goes like this ... class DummyMapper extends KeyedMapper[String,DummyMapper]…
vkantiya
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retrieving field by name from any Mapper in lift

How do we retrieve desired filed from any mapper so as to use it in Query parameter. In my case i want to find records where my 'desired-field' is having value = somevalue. It tried the following way foo(Users) // foo defined here... def foo (…
vkantiya
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foreign key constraint in Lift's mapper

I created a table using Mapper in Scala. class Stage extends Mapper[Stage] { def getSingleton = Stage object controlId extends MappedLongForeignKey (this,Control) { override def dbNotNull_? = true …
NAC
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How do we create Unique Constraint in lift-mapper

How can we create a unique constraint in lift's mapper ?
vkantiya
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Keycloak "Advanced Claim To Group" identity provider mapper example

I am using Keycloak 18.0.2. Okta is one of my configured Identity Providers. I am using the OIDC provider (not SAML). I want to map the incoming groups claim from Okta to a user group I defined in Keycloak. I cannot find a lot of examples on how to…
AnnaSarteNicotera
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It Is possibile to map typescript object to another based on interface/or type

If i have an object in typescript const x = {a:1, b:2} And an interfacce interface MyInterface { a: number } It possibile to do something like (pseudocode) this const y = Mapper(x) console.log(y) // {a: 1} And the result should be…
dna
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Mapping many-to-many relationship to DTO object

Hi like in subject I would like to map entity class to DTO object. Order Class: @Data @AllArgsConstructor @NoArgsConstructor @Entity @Table(name = "ORDERS") public class Order extends BaseEntity { @Column(name = "ORDER_DATE") private…
Oskar
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EmitMapper's List Mapping Issue with Collections

The source class: public class Post { public long ID { get; set; } [Column(TypeName="nvarchar")] [Required] [StringLength(250)] public string Name { get; set; } [Column(TypeName="varchar")] [StringLength(250)] …
fengd
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SQLAlchemy mapping table with non-ascii columns to class

item = Table('Item', metadata, autoload=True, autoload_with=engine, encoding = 'cp1257') class Item(object): pass from sqlalchemy.orm import mapper mapper(Item, item) I get error: line 43, in mapper(Item, item) File…
Atoc
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doctrine 2 join associations not found

I am using Doctrine-2.0.4 with Zend 1.11. Php Mappers and Entities are generated from a MySQL DB. Now I am trying a query that joins two tables and only ever get [Semantical Error] line 0, col 48 near 'e': Error: Class Entities\Users has no…
timt
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How to force Jackson object mapper to ignore not full fields with readerForUpdating().readValue method

I have a class (Jackson annotations/getters/setters/etc are omitted): public class Sample { public String name; public Integer value; } I have an instance, e.g.: Sample sample = new Sample("one", null), and i have a json string: {"name" =…
coolsv
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How to convert map of maps to POJO using Jackson

I have a Map which contains another Map as follows: private ObjectMapper mapper; private Map> indicatorsList; How can I use Jackson in order to convert it to POJO? This is what I was trying to do: public…
אברגיל יעקובו
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