feature #8: Pagination for Query & Function

src/main/kotlin/fr/postgresjson/connexion/Connection.kt

@@ -17,6 +17,7 @@ interface Executable {
     fun <R: EntityI<*>> select(sql: String, typeReference: TypeReference<R>, values: Map<String, Any?>): R?
     fun <R: EntityI<*>> select(sql: String, typeReference: TypeReference<List<R>>, values: List<Any?> = emptyList()): List<R>
     fun <R: EntityI<*>> select(sql: String, typeReference: TypeReference<List<R>>, values: Map<String, Any?>): List<R>
+    fun <R: EntityI<*>> select(sql: String, page: Int, limit: Int, typeReference: TypeReference<List<R>>, values: Map<String, Any?>): Paginated<R>
     fun exec(sql: String, values: List<Any?> = emptyList()): CompletableFuture<QueryResult>
     fun exec(sql: String, values: Map<String, Any?>): CompletableFuture<QueryResult>
 }
@@ -77,7 +78,7 @@ class Connection(
     inline fun <reified R: EntityI<*>> select(sql: String, values: List<Any?> = emptyList()): List<R> =
         select(sql, object: TypeReference<List<R>>() {}, values)
 
-    fun <R: EntityI<*>> select(
+    override fun <R: EntityI<*>> select(
         sql: String,
         page: Int,
         limit: Int,
@@ -108,6 +109,7 @@ class Connection(
             )
         }
     }
+
     inline fun <reified R: EntityI<*>> select(
         sql: String,
         page: Int,

src/main/kotlin/fr/postgresjson/connexion/Requester.kt

@@ -10,8 +10,8 @@ import fr.postgresjson.definition.Function as DefinitionFunction
 class Requester(
     private val connection: Connection,
     private val queries: MutableMap<String, Query> = mutableMapOf(),
-    private val functions: MutableMap<String, Function> = mutableMapOf())
+    private val functions: MutableMap<String, Function> = mutableMapOf()
-{
+) {
     fun addQuery(name: String, query: Query): Requester {
         queries[name] = query
         return this
@@ -82,23 +82,33 @@ class Requester (
         override fun <R: EntityI<*>> select(typeReference: TypeReference<R>, values: List<Any?>): R? {
             return connection.select(this.toString(), typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> selectOne(values: List<Any?> = emptyList()): R? = select(object: TypeReference<R>() {}, values)
 
         override fun <R: EntityI<*>> select(typeReference: TypeReference<R>, values: Map<String, Any?>): R? {
             return connection.select(this.toString(), typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> selectOne(values: Map<String, Any?>): R? = select(object: TypeReference<R>() {}, values)
 
         override fun <R: EntityI<*>> select(typeReference: TypeReference<List<R>>, values: List<Any?>): List<R> {
             return connection.select(this.toString(), typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> select(values: List<Any?> = emptyList()): List<R> = select(object: TypeReference<List<R>>() {}, values)
 
         override fun <R: EntityI<*>> select(typeReference: TypeReference<List<R>>, values: Map<String, Any?>): List<R> {
             return connection.select(this.toString(), typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> select(values: Map<String, Any?>): List<R> = select(object: TypeReference<List<R>>() {}, values)
 
+        override fun <R: EntityI<*>> select(page: Int, limit: Int, typeReference: TypeReference<List<R>>, values: Map<String, Any?>): Paginated<R> {
+            return connection.select(this.toString(), page, limit, typeReference, values)
+        }
+        inline fun <reified R: EntityI<*>> select(page: Int, limit: Int, values: Map<String, Any?> = emptyMap()): Paginated<R> =
+            select(page, limit, object: TypeReference<List<R>>() {}, values)
+
         override fun exec(values: List<Any?>): CompletableFuture<QueryResult> {
             return connection.exec(sql, values)
         }
@@ -122,6 +132,7 @@ class Requester (
 
             return connection.select(sql, typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> selectOne(values: List<Any?> = emptyList()): R? = select(object: TypeReference<R>() {}, values)
 
         /**
@@ -133,6 +144,7 @@ class Requester (
 
             return connection.select(sql, typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> selectOne(values: Map<String, Any?>): R? = select(object: TypeReference<R>() {}, values)
 
         /**
@@ -144,6 +156,7 @@ class Requester (
 
             return connection.select(sql, typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> select(values: List<Any?> = emptyList()): List<R> = select(object: TypeReference<List<R>>() {}, values)
 
         /**
@@ -155,8 +168,23 @@ class Requester (
 
             return connection.select(sql, typeReference, values)
         }
+
         inline fun <reified R: EntityI<*>> select(values: Map<String, Any?>): List<R> = select(object: TypeReference<List<R>>() {}, values)
 
+        override fun <R: EntityI<*>> select(page: Int, limit: Int, typeReference: TypeReference<List<R>>, values: Map<String, Any?>): Paginated<R> {
+            val offset = (page - 1) * limit
+            val newValues = values
+                .plus("offset" to offset)
+                .plus("limit" to limit)
+
+            val args = compileArgs(newValues)
+            val sql = "SELECT * FROM ${definition.name} ($args)"
+
+            return connection.select(sql, page, limit, typeReference, values)
+        }
+        inline fun <reified R: EntityI<*>> select(page: Int, limit: Int, values: Map<String, Any?> = emptyMap()): Paginated<R> =
+            select(page, limit, object: TypeReference<List<R>>() {}, values)
+
         override fun exec(values: List<Any?>): CompletableFuture<QueryResult> {
             val args = compileArgs(values)
             val sql = "SELECT * FROM ${definition.name} ($args)"
@@ -192,7 +220,7 @@ class Requester (
                 }
                 .map { entry ->
                     val parameter = parameters[entry.key]!!
-                    "${parameter.name} := :${parameter.name}::" + parameter.type
+                    """"${parameter.name}" := :${parameter.name}::${parameter.type}"""
                 }
 
             return placeholders.joinToString(separator = ", ")
@@ -209,6 +237,8 @@ class Requester (
         fun <R: EntityI<*>> select(typeReference: TypeReference<List<R>>, values: List<Any?> = emptyList()): List<R>
         fun <R: EntityI<*>> select(typeReference: TypeReference<List<R>>, values: Map<String, Any?>): List<R>
 
+        fun <R: EntityI<*>> select(page: Int, limit: Int, typeReference: TypeReference<List<R>>, values: Map<String, Any?>): Paginated<R>
+
         fun exec(values: List<Any?> = emptyList()): CompletableFuture<QueryResult>
         fun exec(values: Map<String, Any?>): CompletableFuture<QueryResult>
     }
@@ -221,18 +251,15 @@ class Requester (
         private val password: String = "dc-project",
         private val queriesDirectory: File? = null,
         private val functionsDirectory: File? = null
-    )
+    ) {
-    {
+        fun createRequester(): Requester {
-        fun createRequester(): Requester
-        {
             val con = Connection(host = host, port = port, database = database, username = username, password = password)
             val req = Requester(con)
 
             return initRequester(req)
         }
 
-        private fun initRequester(req: Requester): Requester
+        private fun initRequester(req: Requester): Requester {
-        {
             if (queriesDirectory === null) {
                 val resource = this::class.java.getResource("/sql/query")
                 if (resource !== null) {

src/test/kotlin/fr/postgresjson/RequesterTest.kt

@@ -2,8 +2,10 @@ package fr.postgresjson
 
 import com.github.jasync.sql.db.QueryResult
 import com.github.jasync.sql.db.util.isCompleted
+import fr.postgresjson.connexion.Paginated
 import fr.postgresjson.connexion.Requester
 import fr.postgresjson.entity.IdEntity
+import org.junit.Assert
 import org.junit.jupiter.api.Assertions
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
@@ -93,4 +95,32 @@ class RequesterTest: TestAbstract() {
 
         assertEquals("myName", obj!![0].name)
     }
+
+    @Test
+    fun `call select paginated on query`() {
+        val resources = File(this::class.java.getResource("/sql/query").toURI())
+        val result: Paginated<ObjTest> = Requester(getConnextion())
+            .addQuery(resources)
+            .getQuery("Test/selectPaginated")
+            .select(1, 2, mapOf("name" to "ff"))
+        Assert.assertNotNull(result)
+        Assert.assertEquals(result.result[0].name, "ff")
+        Assert.assertEquals(result.result[1].name, "ff-2")
+        Assert.assertEquals(result.total, 10)
+        Assert.assertEquals(result.offset, 0)
+    }
+
+    @Test
+    fun `call select paginated on function`() {
+        val resources = File(this::class.java.getResource("/sql/function").toURI())
+        val result: Paginated<ObjTest> = Requester(getConnextion())
+            .addFunction(resources)
+            .getFunction("test_function_paginated")
+            .select(1, 2, mapOf("name" to "ff"))
+        Assert.assertNotNull(result)
+        Assert.assertEquals(result.result[0].name, "ff")
+        Assert.assertEquals(result.result[1].name, "ff-2")
+        Assert.assertEquals(result.total, 10)
+        Assert.assertEquals(result.offset, 0)
+    }
 }

src/test/resources/fixtures/init.sql

@@ -49,3 +49,18 @@ BEGIN
         );
 END;
 $$;
+
+CREATE OR REPLACE FUNCTION test_function_paginated (name text default 'plop', IN "limit" int default 10, IN "offset" int default 0, out result json, out total int)
+    LANGUAGE plpgsql
+AS
+$$
+BEGIN
+    SELECT json_build_array(
+                   json_build_object('id', 3, 'name', name::text),
+                   json_build_object('id', 4, 'name', name::text || '-2')
+               ),
+           10
+    INTO result, total
+    LIMIT "limit" OFFSET "offset";
+END;
+$$

src/test/resources/sql/function/Test/test_function_paginated.sql

@@ -0,0 +1,14 @@
+CREATE OR REPLACE FUNCTION test_function_paginated (name text default 'plop', IN "limit" int default 10, IN "offset" int default 0, out result json, out total int)
+LANGUAGE plpgsql
+AS
+$$
+BEGIN
+    SELECT json_build_array(
+        json_build_object('id', 3, 'name', name::text),
+        json_build_object('id', 4, 'name', name::text || '-2')
+    ),
+    10
+    INTO result, total
+    LIMIT "limit" OFFSET "offset";
+END;
+$$

src/test/resources/sql/query/Test/selectPaginated.sql

@@ -0,0 +1,5 @@
+SELECT json_build_array(
+   json_build_object('id', 3, 'name', :name::text),
+   json_build_object('id', 4, 'name', :name::text || '-2')
+), 10 as total
+LIMIT :limit OFFSET :offset