address comments and reorganize code examples

documentation-website/Writerside/hi.tree

@@ -29,6 +29,7 @@
     </toc-element>
     <toc-element toc-title="Deep Dive into DAO">
         <toc-element topic="DAO-Table-Types.topic"/>
+        <toc-element topic="DAO-Entity-definition.topic"/>
         <toc-element topic="DAO-CRUD-Operations.topic"/>
         <toc-element topic="DAO-Relationships.topic"/>
         <toc-element topic="DAO-Field-Transformations.topic"/>

documentation-website/Writerside/snippets/exposed-dao/src/main/kotlin/org/example/App.kt

@@ -1,138 +1,34 @@
 package org.example
 
-import org.example.entities.*
-import org.example.tables.*
-import org.jetbrains.exposed.dao.id.CompositeID
-import org.jetbrains.exposed.sql.*
-import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
+import org.example.examples.*
+import org.example.tables.CitiesTable
+import org.example.tables.DirectorsTable
+import org.example.tables.StarWarsFilmsTable
+import org.example.tables.UserRatingsTable
+import org.example.tables.UsersTable
+import org.jetbrains.exposed.sql.Database
+import org.jetbrains.exposed.sql.SchemaUtils
+import org.jetbrains.exposed.sql.StdOutSqlLogger
+import org.jetbrains.exposed.sql.addLogger
 import org.jetbrains.exposed.sql.transactions.transaction
-import java.util.*
 
 fun main() {
     Database.connect("jdbc:h2:mem:test", driver = "org.h2.Driver")
 
     transaction {
         addLogger(StdOutSqlLogger)
-        createFilms()
-        createDirectors()
-        createUsersAndRatings()
-    }
-}
-
-fun createFilms() {
-    SchemaUtils.create(StarWarsFilmsTable)
-
-    // Create a new record
-    val movie = StarWarsFilmEntity.new {
-        name = "The Last Jedi"
-        sequelId = 8
-        director = "Rian Johnson"
-    }
-
-    // Create a new record with id
-    StarWarsFilmEntity.new(id = 2) {
-        name = "The Rise of Skywalker"
-        sequelId = 9
-        director = "J.J. Abrams"
-    }
-
-    // Read a property value
-    val movieName = movie.name
-    println("Created a new film named $movieName")
-
-    // Read the id value
-    val movieId: Int = movie.id.value
-    println("The id of the new movie is $movieId")
-
-    // Read all movies
-    val allMovies = StarWarsFilmEntity.all()
-    allMovies.forEach({ println(it.name) })
-
-    // Sort results in ascending order
-    val moviesByAscOrder = StarWarsFilmEntity.all().sortedBy { it.sequelId }
-    moviesByAscOrder.map { println(it.sequelId) }
-
-    // Sort results in descending order
-    val moviesByDescOrder = StarWarsFilmEntity.all().sortedByDescending { it.sequelId }
-    moviesByDescOrder.map { println(it.sequelId) }
-
-    // Read all with a condition
-    val specificMovie = StarWarsFilmEntity.find { StarWarsFilmsTable.sequelId eq 8 }
-     specificMovie.forEach({ println("Found a movie with sequelId 8 and name " + it.name) })
-
-    // Get an entity by its id value
-    val fifthMovie = StarWarsFilmEntity.findById(5)
-    println(fifthMovie?.name)
-
-    // Update an entity value
-    movie.name = "Episode VIII – The Last Jedi"
-
-    // Find by id and update
-    val updatedMovie = StarWarsFilmEntity.findByIdAndUpdate(5) {
-        it.name = "Episode VIII – The Last Jedi"
-    }
-    println(updatedMovie?.name)
-
-    // Find a single record by a condition and update
-    val updatedMovie2 = StarWarsFilmEntity.findSingleByAndUpdate(StarWarsFilmsTable.name eq "The Last Jedi") {
-        it.name = "Episode VIII – The Last Jedi"
-    }
-    println(updatedMovie2?.name)
-
-    // Delete a record
-    movie.delete()
-}
-
-fun createDirectors() {
-    SchemaUtils.create(DirectorsTable)
-
-    val directorId = CompositeID {
-        it[DirectorsTable.name] = "J.J. Abrams"
-        it[DirectorsTable.guildId] = UUID.randomUUID()
-    }
+        SchemaUtils.create(StarWarsFilmsTable)
+        SchemaUtils.create(DirectorsTable)
+        SchemaUtils.create(UsersTable)
+        SchemaUtils.create(UserRatingsTable)
+        SchemaUtils.create(CitiesTable)
 
-    DirectorEntity.new(directorId) {
-        genre = Genre.SCI_FI
-    }
-
-    // Find records by composite id
-    /*
-        SELECT DIRECTORS."name", DIRECTORS.GUILD_ID, DIRECTORS.GENRE
-        FROM DIRECTORS
-        WHERE (DIRECTORS."name" = 'J.J. Abrams')
-        AND (DIRECTORS.GUILD_ID = '2cc64f4f-1a2c-41ce-bda1-ee492f787f4b')
-     */
-    val directors = DirectorEntity.find { DirectorsTable.id eq directorId }
-    directors.forEach({ println(it.genre) })
-}
-
-fun createUsersAndRatings() {
-    SchemaUtils.create(UsersTable)
-    SchemaUtils.create(UserRatingsTable)
-    SchemaUtils.create(CitiesTable)
+        // Create examples
+        val createExamples = CreateExamples()
+        createExamples.createFilms()
 
-    // Read an entity with a join to another table
-    val query = UsersTable.innerJoin(UserRatingsTable).innerJoin(StarWarsFilmsTable)
-        .select(UsersTable.columns)
-        .where {
-            StarWarsFilmsTable.sequelId eq 2 and (UserRatingsTable.value greater 5)
-        }.withDistinct()
-
-    val users = UserEntity.wrapRows(query).toList()
-    users.map { println(it.name) }
-
-    CitiesTable.insert {
-        it[name] = "Amsterdam"
+        // Read examples
+        val readExamples = ReadExamples()
+        readExamples.readExamples()
     }
-
-    // Use a query as an expression to sort cities by the number of users in each city
-    val expression = wrapAsExpression<Int>(
-        UsersTable.select(UsersTable.id.count())
-            .where { CitiesTable.id eq UsersTable.cityId }
-    )
-    val cities = CitiesTable.selectAll()
-        .orderBy(expression, SortOrder.DESC)
-        .toList()
-
-    cities.map { println(it[CitiesTable.name]) }
 }

documentation-website/Writerside/snippets/exposed-dao/src/main/kotlin/org/example/entities/ComputedFieldEntity.kt

@@ -0,0 +1,25 @@
+package org.example.entities
+
+import org.example.tables.StarWarsWFilmsWithRankTable
+import org.jetbrains.exposed.dao.IntEntity
+import org.jetbrains.exposed.dao.IntEntityClass
+import org.jetbrains.exposed.dao.id.EntityID
+import org.jetbrains.exposed.sql.Op
+import org.jetbrains.exposed.sql.Query
+
+class StarWarsWFilmWithRankEntity(id: EntityID<Int>) : IntEntity(id) {
+    var sequelId by StarWarsWFilmsWithRankTable.sequelId
+    var name by StarWarsWFilmsWithRankTable.name
+    var rating by StarWarsWFilmsWithRankTable.rating
+
+    val rank: Long
+        get() = readValues[StarWarsWFilmsWithRankTable.rank]
+
+    companion object : IntEntityClass<StarWarsWFilmWithRankEntity>(StarWarsWFilmsWithRankTable) {
+        override fun searchQuery(op: Op<Boolean>): Query {
+            return super.searchQuery(op).adjustSelect {
+                select(columns + StarWarsWFilmsWithRankTable.rank)
+            }
+        }
+    }
+}

documentation-website/Writerside/snippets/exposed-dao/src/main/kotlin/org/example/entities/CustomColumnTypeEntity.kt

@@ -0,0 +1,12 @@
+package org.example.entities
+
+import org.example.tables.DirectorsCustomTable
+import org.jetbrains.exposed.dao.Entity
+import org.jetbrains.exposed.dao.EntityClass
+import org.jetbrains.exposed.dao.id.EntityID
+
+class DirectorCustomEntity(id: EntityID<String>) : Entity<String>(id) {
+    companion object : EntityClass<String, DirectorCustomEntity>(DirectorsCustomTable)
+
+    var name by DirectorsCustomTable.name
+}

documentation-website/Writerside/snippets/exposed-dao/src/main/kotlin/org/example/examples/CreateExamples.kt

@@ -0,0 +1,37 @@
+package org.example.examples
+
+import org.example.entities.DirectorEntity
+import org.example.entities.StarWarsFilmEntity
+import org.example.tables.DirectorsTable
+import org.example.tables.Genre
+import org.jetbrains.exposed.dao.id.CompositeID
+import java.util.*
+
+class CreateExamples {
+    fun createFilms() {
+        val movie = StarWarsFilmEntity.new {
+            name = "The Last Jedi"
+            sequelId = 8
+            director = "Rian Johnson"
+        }
+
+        // Create a new record with id
+        val movie2 = StarWarsFilmEntity.new(id = 2) {
+            name = "The Rise of Skywalker"
+            sequelId = 9
+            director = "J.J. Abrams"
+        }
+    }
+
+    fun createNewWithCompositeId() {
+        val directorId = CompositeID {
+            it[DirectorsTable.name] = "J.J. Abrams"
+            it[DirectorsTable.guildId] = UUID.randomUUID()
+        }
+
+        val director = DirectorEntity.new(directorId) {
+            genre = Genre.SCI_FI
+        }
+    }
+
+}

documentation-website/Writerside/snippets/exposed-dao/src/main/kotlin/org/example/examples/DeleteExamples.kt

@@ -0,0 +1,14 @@
+package org.example.examples
+
+import org.example.entities.StarWarsFilmEntity
+
+class DeleteExamples {
+    fun deleteFilm() {
+        val movie = StarWarsFilmEntity.new {
+            name = "The Last Jedi"
+            sequelId = 8
+            director = "Rian Johnson"
+        }
+        val deletedMovie = movie.delete()
+    }
+}

documentation-website/Writerside/snippets/exposed-dao/src/main/kotlin/org/example/examples/ReadExamples.kt

@@ -0,0 +1,105 @@
+package org.example.examples
+
+import org.example.entities.DirectorEntity
+import org.example.entities.StarWarsFilmEntity
+import org.example.entities.StarWarsWFilmWithRankEntity
+import org.example.entities.UserEntity
+import org.example.tables.CitiesTable
+import org.example.tables.DirectorsTable
+import org.example.tables.StarWarsFilmsTable
+import org.example.tables.UserRatingsTable
+import org.example.tables.UsersTable
+import org.jetbrains.exposed.dao.id.CompositeID
+import org.jetbrains.exposed.sql.SortOrder
+import org.jetbrains.exposed.sql.and
+import org.jetbrains.exposed.sql.count
+import org.jetbrains.exposed.sql.insert
+import org.jetbrains.exposed.sql.selectAll
+import org.jetbrains.exposed.sql.wrapAsExpression
+import java.util.*
+
+class ReadExamples {
+    fun readAll() {
+        // Read all movies
+        val allMovies = StarWarsFilmEntity.all()
+        allMovies.forEach({ println(it.name) })
+
+        // Sort results in ascending order
+        val moviesByAscOrder = StarWarsFilmEntity.all().sortedBy { it.sequelId }
+        moviesByAscOrder.map { println(it.sequelId) }
+
+        // Sort results in descending order
+        val moviesByDescOrder = StarWarsFilmEntity.all().sortedByDescending { it.sequelId }
+        moviesByDescOrder.map { println(it.sequelId) }
+    }
+
+    fun find() {
+        // Get an entity by its id value
+        val movie = StarWarsFilmEntity.findById(2)
+
+        if(movie != null) {
+            // Read a property value
+            val movieName = movie.name
+            println("Created a new film named $movieName")
+
+            // Read the id value
+            val movieId: Int = movie.id.value
+            println("The id of the new movie is $movieId")
+        }
+
+        // Read all with a condition
+        val specificMovie = StarWarsFilmEntity.find { StarWarsFilmsTable.sequelId eq 8 }
+        specificMovie.forEach({ println("Found a movie with sequelId 8 and name " + it.name) })
+    }
+
+    // Read an entity with a join to another table
+    fun readWithJoin() {
+        val query = UsersTable.innerJoin(UserRatingsTable).innerJoin(StarWarsFilmsTable)
+            .select(UsersTable.columns)
+            .where {
+                StarWarsFilmsTable.sequelId eq 2 and (UserRatingsTable.value greater 5)
+            }.withDistinct()
+
+        val users = UserEntity.wrapRows(query).toList()
+        users.map { println(it.name) }
+    }
+
+    fun findByCompositeId() {
+        // Find records by composite id
+        val directorId = CompositeID {
+            it[DirectorsTable.name] = "J.J. Abrams"
+            it[DirectorsTable.guildId] = UUID.randomUUID()
+        }
+
+        val directors = DirectorEntity.find { DirectorsTable.id eq directorId }
+        directors.forEach({ println(it.genre) })
+    }
+
+    fun queriesAsExpressions() {
+        // Use a query as an expression to sort cities by the number of users in each city
+        CitiesTable.insert {
+            it[name] = "Amsterdam"
+        }
+
+        val expression = wrapAsExpression<Int>(
+            UsersTable.select(UsersTable.id.count())
+                .where { CitiesTable.id eq UsersTable.cityId }
+        )
+        val cities = CitiesTable.selectAll()
+            .orderBy(expression, SortOrder.DESC)
+            .toList()
+
+        cities.map { println(it[CitiesTable.name]) }
+    }
+
+    fun readComputedField() {
+        StarWarsWFilmWithRankEntity.new {
+            sequelId = 8
+            name = "The Last Jedi"
+            rating = 4.2
+        }
+
+        StarWarsWFilmWithRankEntity.find { StarWarsFilmsTable.name like "The%" }.map { it.name to it.rank }
+    }
+
+}

documentation-website/Writerside/snippets/exposed-dao/src/main/kotlin/org/example/examples/UpdateExamples.kt

@@ -0,0 +1,22 @@
+package org.example.examples
+
+import org.example.entities.StarWarsFilmEntity
+import org.example.tables.StarWarsFilmsTable
+import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
+
+class UpdateExamples {
+    fun updateFilms() {
+        // Find by id and update
+        val updatedMovie = StarWarsFilmEntity.findByIdAndUpdate(5) {
+            it.name = "Episode VIII – The Last Jedi"
+        }
+        println(updatedMovie?.name)
+
+        // Find a single record by a condition and update
+        val updatedMovie2 = StarWarsFilmEntity.findSingleByAndUpdate(StarWarsFilmsTable.name eq "The Last Jedi") {
+            it.name = "Episode VIII – The Last Jedi"
+        }
+        println(updatedMovie2?.name)
+    }
+
+}