play slick pg full text example

play-slick-pg-full-text-example

مثال على كيفية استخدام ملحقات Tminglei Slick PostgreSQL للبحث عن النص الكامل.

مكدس التكنولوجيا

• إطار اللعب
• سكالا
• postgresql
• بقعة

أجزاء رئيسية من الكود

ها هو نص تطور SQL. لاحظ أن هناك مشغل يقوم بتحديث TSVector Search_field ، وأن هناك فهرسًا على Search_field:

 # --- !Ups

CREATE SCHEMA app ;

CREATE TABLE app .document (
  id            BIGSERIAL NOT NULL PRIMARY KEY ,
  content       TEXT ,
  search_field  tsvector
);

CREATE FUNCTION app .update_document_search_field() RETURNS TRIGGER AS $$
BEGIN
    NEW . search_field : = to_tsvector( NEW . content );;
    RETURN NEW;;
END;;
$$ LANGUAGE plpgsql;

CREATE TRIGGER tr_update_document_search_field
BEFORE INSERT OR UPDATE ON app . document
FOR EACH ROW EXECUTE FUNCTION app . update_document_search_field ();

CREATE INDEX document_result_search_idx ON app . document USING GIN(search_field);

# ---!Downs

DROP TABLE app . document ;
DROP FUNCTION app . update_document_search_field ();
DROP SCHEMA app;

نموذج بيانات بسيط:

 package models

import utils . StringUtils

case class Document ( id : Option [ Long ], content : String ) {
  lazy val abbreviatedContent : String = StringUtils .ellipses(content, 100 )
}

case class Page [ T ]( items : Seq [ T ], page : Int , offset : Int , total : Long , totalPageCount : Long ) {
  lazy val prev : Option [ Int ] = Option (page - 1 ).filter(_ >= 0 )
  lazy val next : Option [ Int ] = Option (page + 1 ).filter(_ => (offset + items.size) < total)
}

case class SearchResult ( highlights : String , rank : Float , document : Document )

ملف تعريف Tminglei Postgres:

 package models . daos

import com . github . tminglei . slickpg . _

trait MyPostgresProfile extends ExPostgresProfile
  with PgArraySupport
  with PgDate2Support
  with PgRangeSupport
  with PgHStoreSupport
  with PgSearchSupport
  with PgNetSupport
  with PgLTreeSupport {

  // Add back `capabilities.insertOrUpdate` to enable native `upsert` support; for postgres 9.5+
  override protected def computeCapabilities : Set [slick.basic. Capability ] =
    super .computeCapabilities + slick.jdbc. JdbcCapabilities .insertOrUpdate

  override val api : MyAPI = new MyAPI { }

  trait MyAPI extends ExtPostgresAPI with ArrayImplicits
    with Date2DateTimeImplicitsDuration
    with NetImplicits
    with LTreeImplicits
    with RangeImplicits
    with HStoreImplicits
    with SearchImplicits
    with SearchAssistants {

  }
}

object MyPostgresProfile extends MyPostgresProfile

تعريف جدول البقعة الذي يستخدم الملف الشخصي:

 package models . daos

import MyPostgresProfile . api . _
import com . github . tminglei . slickpg . TsVector
import models . Document
import slick . lifted . ProvenShape

trait TableDefinitions {
  class DocumentTable ( tag : Tag ) extends Table [ Document ](tag, Some ( " app " ), " document " ) {
    def id = column[ Long ]( " id " , O . PrimaryKey , O . AutoInc )
    def content = column[ String ]( " content " )
    def searchField = column[ TsVector ]( " search_field " )
    def * : ProvenShape [ Document ] = (id. ? , content) <> ( Document .tupled, Document .unapply)
  }

  val documentTableQuery = TableQuery [ DocumentTable ]
}

تطبيق documentDao. انتبه إلى طريقة search :

 package models . daos

import models .{ Document , Page , SearchResult }
import MyPostgresProfile . api . _
import play . api . Logging
import play . api . db . slick . DatabaseConfigProvider

import javax . inject . Inject
import scala . concurrent .{ ExecutionContext , Future }

class DocumentDAOImpl @ Inject () ( val dbConfigProvider : DatabaseConfigProvider )( implicit ec : ExecutionContext )
  extends DocumentDAO with DAOSlick with Logging {

  def get ( id : Long ) : Future [ Option [ Document ]] = {
    val query = documentTableQuery.filter(_.id === id)
    db.run(query.result.headOption)
  }

  def list ( page : Int , pageSize : Int ) : Future [ Page [ Document ]] = {
    val offset = page * pageSize
    val paginatedQuery = documentTableQuery.sortBy(_.id.desc).drop(offset).take(pageSize)
    getDocuments(page, pageSize, offset, paginatedQuery, documentTableQuery)
  }

  def saveNewDocument ( content : String ) : Future [ Document ] = {
    val insertQuery = (documentTableQuery returning documentTableQuery.map(_.id)) += Document ( None , content)
    db.run(insertQuery).flatMap(documentId => get(documentId).map(_.get))
  }

  def saveExistingDocument ( id : Long , content : String ) : Future [ Document ] = {
    val document = Document ( Some (id), content)
    val updateQuery = documentTableQuery.filter(_.id === id).update(document)
    db.run(updateQuery).map(_ => document)
  }

  def search ( query : String , page : Int , pageSize : Int ) : Future [ Page [ SearchResult ]] = {
    val offset = page * pageSize
    val totalQuery = documentTableQuery.filter(table => table.searchField @@ webSearchToTsQuery(query))
    val searchResultsQuery = totalQuery.map(t => (t.id, t.content, tsHeadline(t.content, webSearchToTsQuery(query)),
        tsRankCD(t.searchField, webSearchToTsQuery(query)))).sortBy(_._4.desc)

    val paginatedQuery = searchResultsQuery.drop(offset).take(pageSize)

    for {
      searchResults <- db.run(paginatedQuery.result) map {
        results => results.map {
          case (id, content, highlight, rank) => SearchResult (highlights = highlight, rank = rank, document = Document ( Some (id), content))
        }
      }
      totalCount <- db.run(totalQuery.length.result)
    } yield Page (searchResults, page, offset, totalCount.toLong, calculateTotalPages(pageSize, totalCount.toLong))
  }

  private def getDocuments ( page : Int , pageSize : Int , offset : Int , paginatedQuery : Query [ DocumentTable , Document , Seq ],
                           totalQuery : Query [ DocumentTable , Document , Seq ]) = {
    for {
      documents <- db.run(paginatedQuery.result)
      totalCount <- db.run(totalQuery.length.result)
    } yield Page (documents, page, offset, totalCount.toLong, calculateTotalPages(pageSize, totalCount.toLong))
  }

  private def calculateTotalPages ( pageSize : Int , totalCount : Long ) = {
    (totalCount.toFloat / pageSize).ceil.toLong
  }
}

ما تبقى من الكود في الغالب لواجهة مستخدم الويب الخام.