diff --git a/src/main/kotlin/fr/postgresjson/connexion/Connection.kt b/src/main/kotlin/fr/postgresjson/connexion/Connection.kt
index a1b482a..1c33eab 100644
--- a/src/main/kotlin/fr/postgresjson/connexion/Connection.kt
+++ b/src/main/kotlin/fr/postgresjson/connexion/Connection.kt
@@ -11,39 +11,148 @@ import kotlin.text.RegexOption.IGNORE_CASE
 import kotlin.text.RegexOption.MULTILINE
 
 class Connection(
+    private val database: String,
+    private val username: String,
+    private val password: String,
     private val host: String = "localhost",
-    private val port: Int = 5432,
-    private val database: String = "dc-project",
-    private val username: String = "dc-project",
-    private val password: String = "dc-project",
-    queriesDirectory: File? = null,
-    functionsDirectory: File? = null
+    private val port: Int = 5432
 ) {
-    private val queries = mutableMapOf<String, Query>()
-    private val functions = mutableMapOf<String, Function>()
     private lateinit var connection: ConnectionPool<PostgreSQLConnection>
     private val serializer = Serializer()
 
-    init {
-        if (queriesDirectory === null) {
-            val resource = this::class.java.getResource("/sql/query")
-            if (resource !== null) {
-                fetchQueries(File(resource.toURI()))
-            }
-        } else {
-            fetchQueries(queriesDirectory)
+    fun connect(): ConnectionPool<PostgreSQLConnection> {
+        if (!::connection.isInitialized || !connection.isConnected()) {
+            connection = PostgreSQLConnectionBuilder.createConnectionPool(
+                "jdbc:postgresql://$host:$port/$database?user=$username&password=$password"
+            )
         }
+        return connection
+    }
 
-        if (functionsDirectory === null) {
-            val resource = this::class.java.getResource("/sql/function")
-            if (resource !== null) {
-                fetchFunctions(File(resource.toURI()))
-            }
+    fun <T, R : EntityI<T?>?> selectOne(sql: String, typeReference: TypeReference<R>, values: List<Any?> = emptyList()): R? {
+        val future = connect().sendPreparedStatement(sql, values)
+        val json = future.get().rows[0].getString(0)
+        return if (json === null) {
+            null
         } else {
-            fetchFunctions(functionsDirectory)
+            serializer.deserialize(json, typeReference)
         }
     }
 
+    inline fun <T, reified R : EntityI<T?>?> selectOne(sql: String, values: List<Any?> = emptyList()): R? = selectOne(sql, object: TypeReference<R>() {}, values)
+
+    fun <T, R : List<EntityI<T?>?>> select(sql: String, typeReference: TypeReference<R>, values: List<Any?> = emptyList()): R {
+        val future = connect().sendPreparedStatement(sql, values)
+        val json = future.get().rows[0].getString(0)
+        return if (json === null) {
+            listOf<EntityI<T?>?>() as R
+        } else {
+            serializer.deserializeList(json, typeReference)
+        }
+    }
+
+    inline fun <T, reified R : List<EntityI<T?>?>> select(sql: String, values: List<Any?> = emptyList()): R = select(sql, object : TypeReference<R>() {}, values)
+}
+
+class Requester (
+    private val connection: Connection,
+    queries: List<Query> = listOf(),
+    functions: List<Function> = listOf())
+{
+    private val queries = mutableMapOf<String, Query>()
+    private val functions = mutableMapOf<String, Function>()
+
+    fun addQuery(name: String, query: Query): Requester {
+        queries[name] = query
+        return this
+    }
+
+    fun addQuery(name: String, sql: String): Requester {
+        queries[name] = Query(sql, connection)
+        return this
+    }
+
+    fun addQuery(queriesDirectory: File): Requester {
+        queriesDirectory.walk().filter { it.isDirectory }.forEach { directory ->
+            val path = directory.name
+            directory.walk().filter { it.isFile }.forEach { file ->
+                val sql = file.readText()
+                val fullpath = "$path/${file.nameWithoutExtension}"
+                queries[fullpath] = Query(sql, connection)
+            }
+        }
+        return this
+    }
+
+    fun addFunction(function: Function): Requester {
+        functions[function.name] = function
+        return this
+    }
+
+    fun addFunction(sql: String): Requester {
+        getDefinitions(sql).forEach {
+            functions[it.name] = it
+        }
+        return this
+    }
+
+    fun addFunction(functionsDirectory: File): Requester {
+        functionsDirectory.walk().filter {
+            it.isDirectory
+        }.forEach { directory ->
+            directory.walk().filter {
+                it.isFile
+            }.forEach { file ->
+                val fileContent = file.readText()
+                addFunction(fileContent)
+            }
+        }
+        return this
+    }
+
+    private fun getDefinitions(functionContent: String): List<Function> {
+        val functionRegex = """create .*(procedure|function) *(?<name>[^(\s]+)\s*\((?<params>(\s*((IN|OUT|INOUT|VARIADIC)?\s+)?([^\s,)]+\s+)?([^\s,)]+)(\s+(?:default\s|=)\s*[^\s,)]+)?\s*(,|(?=\))))*)\) *(?<return>RETURNS *[^ ]+)?"""
+            .toRegex(setOf(IGNORE_CASE, MULTILINE))
+
+        val paramsRegex = """\s*(?<param>((?<direction>IN|OUT|INOUT|VARIADIC)?\s+)?(?<name>[^\s,)]+\s+)?(?<type>[^\s,)]+)(\s+(?:default\s|=)\s*[^\s,)]+)?)\s*(,|$)"""
+            .toRegex(setOf(IGNORE_CASE, MULTILINE))
+
+        return functionRegex.findAll(functionContent).map { queryMatch ->
+            val functionName = queryMatch.groups["name"]?.value?.trim()
+            val functionParameters = queryMatch.groups["params"]?.value?.trim()
+            val returns = queryMatch.groups["return"]?.value?.trim()
+
+            /* Create parameters definition */
+            val parameters = if (functionParameters !== null) {
+                val matchesParams = paramsRegex.findAll(functionParameters)
+                matchesParams.map { paramsMatch ->
+                    Function.Parameter(
+                        paramsMatch.groups["name"]!!.value.trim(),
+                        paramsMatch.groups["type"]!!.value.trim(),
+                        paramsMatch.groups["direction"]?.value?.trim())
+                }.toList()
+            } else {
+                listOf()
+            }
+
+            Function(functionName!!, parameters, connection)
+        }.toList()
+    }
+
+    fun getFunction(name: String): Function {
+        if (functions[name] === null) {
+            throw Exception("No function defined for $name")
+        }
+        return functions[name]!!
+    }
+
+    fun getQuery(path: String): Query {
+        if (queries[path] === null) {
+            throw Exception("No query defined for $path")
+        }
+        return queries[path]!!
+    }
+
     class Query(private val sql: String, private val connection : Connection) {
         override fun toString(): String {
             return sql
@@ -87,125 +196,64 @@ class Connection(
             return name
         }
 
-        fun <T, R : EntityI<T?>?> selectOne(typeReference: TypeReference<R>, values: List<Any?> = emptyList()): R? {
-            val args = values.joinToString()
-            val sql = "SELECT * FROM $name ($args)"
+        fun <T, R : EntityI<T?>?> selectOne(typeReference: TypeReference<R>, values: List<String?> = emptyList()): R? {
+            val placeholder = List(values.size) {"?"}.joinToString(separator=", ")
+            val sql = "SELECT * FROM $name (${placeholder})"
 
             return connection.selectOne(sql, typeReference, values)
         }
 
-        inline fun <T, reified R: EntityI<T?>?> selectOne(values: List<Any?> = emptyList()): R? = selectOne(object: TypeReference<R>() {}, values)
+        inline fun <T, reified R: EntityI<T?>?> selectOne(values: List<String?> = emptyList()): R? = selectOne(object: TypeReference<R>() {}, values)
 
         fun <T, R : List<EntityI<T?>?>> select(typeReference: TypeReference<R>, values: List<Any?> = emptyList()): R? {
-            val args = values.joinToString()
-            val sql = "SELECT * FROM $name ($args)"
+            val placeholder = List(values.size) {"?"}.joinToString(separator=", ")
+            val sql = "SELECT * FROM $name ($placeholder)"
 
             return connection.select(sql, typeReference, values)
         }
 
         inline fun <T, reified R: List<EntityI<T?>?>> select(values: List<Any?> = emptyList()): R? = select(object: TypeReference<R>() {}, values)
     }
+}
 
-    fun connect(): ConnectionPool<PostgreSQLConnection> {
-        if (!::connection.isInitialized || !connection.isConnected()) {
-            connection = PostgreSQLConnectionBuilder.createConnectionPool(
-                "jdbc:postgresql://$host:$port/$database?user=$username&password=$password"
-            )
-        }
-        return connection
-    }
-
-    fun <T, R : EntityI<T?>?> selectOne(sql: String, typeReference: TypeReference<R>, values: List<Any?> = emptyList()): R? {
-        val future = connect().sendPreparedStatement(sql, values)
-        val json = future.get().rows[0].getString(0)
-        return if (json === null) {
-            null
-        } else {
-            serializer.deserialize<T, R>(json, typeReference)
-        }
-    }
-
-    inline fun <T, reified R : EntityI<T?>?> selectOne(sql: String, values: List<Any?> = emptyList()): R? = selectOne(sql, object: TypeReference<R>() {}, values)
-
-    fun <T, R : List<EntityI<T?>?>> select(sql: String, typeReference: TypeReference<R>, values: List<Any?> = emptyList()): R {
-        val future = connect().sendPreparedStatement(sql, values)
-        val json = future.get().rows[0].getString(0)
-        return if (json === null) {
-            listOf<EntityI<T?>?>() as R
-        } else {
-            serializer.deserializeList(json, typeReference)
-        }
-    }
-
-    inline fun <T, reified R : List<EntityI<T?>?>> select(sql: String, values: List<Any?> = emptyList()): R = select(sql, object : TypeReference<R>() {}, values)
-
-    private fun fetchQueries(queriesDirectory: File) {
-        queriesDirectory.walk().filter { it.isDirectory }.forEach { directory ->
-            val path = directory.name
-            directory.walk().filter { it.isFile }.forEach { file ->
-                val sql = file.readText()
-                val fullpath = "$path/${file.nameWithoutExtension}"
-                queries[fullpath] = Query(sql, this)
-            }
-        }
-    }
-
-    private fun fetchFunctions(functionsDirectory: File) {
-        functionsDirectory.walk().filter {
-            it.isDirectory
-        }.forEach { directory ->
-            directory.walk().filter {
-                it.isFile
-            }.forEach { file ->
-                val fileContent = file.readText()
-                getDefinitions(fileContent).forEach {
-                    functions[it.name] = it
-                }
-            }
-        }
-    }
-
-    private fun getDefinitions(functionContent: String): List<Function>
+class RequesterFactory(
+    private val host: String = "localhost",
+    private val port: Int = 5432,
+    private val database: String = "dc-project",
+    private val username: String = "dc-project",
+    private val password: String = "dc-project",
+    private val queriesDirectory: File? = null,
+    private val functionsDirectory: File? = null
+)
+{
+    fun createRequester(): Requester
     {
-        val functionRegex = """create .*(procedure|function) *(?<name>[^(\s]+)\s*\((?<params>(\s*((IN|OUT|INOUT|VARIADIC)?\s+)?([^\s,)]+\s+)?([^\s,)]+)(\s+(?:default\s|=)\s*[^\s,)]+)?\s*(,|(?=\))))*)\) *(?<return>RETURNS *[^ ]+)?"""
-            .toRegex(setOf(IGNORE_CASE, MULTILINE))
+        val con = Connection(host = host, port = port, database = database, username = username, password = password)
+        val req = Requester(con)
 
-        val paramsRegex = """\s*(?<param>((?<direction>IN|OUT|INOUT|VARIADIC)?\s+)?(?<name>[^\s,)]+\s+)?(?<type>[^\s,)]+)(\s+(?:default\s|=)\s*[^\s,)]+)?)\s*(,|$)"""
-            .toRegex(setOf(IGNORE_CASE, MULTILINE))
+        return initRequester(req)
+    }
 
-        return functionRegex.findAll(functionContent).map { queryMatch ->
-            val functionName = queryMatch.groups["name"]?.value?.trim()
-            val functionParameters = queryMatch.groups["params"]?.value?.trim()
-            val returns = queryMatch.groups["return"]?.value?.trim()
-
-            /* Create parameters definition */
-            val parameters = if (functionParameters !== null) {
-                val matchesParams = paramsRegex.findAll(functionParameters)
-                matchesParams.map { paramsMatch ->
-                    Function.Parameter(
-                        paramsMatch.groups["name"]!!.value.trim(),
-                        paramsMatch.groups["type"]!!.value.trim(),
-                        paramsMatch.groups["direction"]?.value?.trim())
-                }.toList()
-            } else {
-                listOf()
+    private fun initRequester(req: Requester): Requester
+    {
+        if (queriesDirectory === null) {
+            val resource = this::class.java.getResource("/sql/query")
+            if (resource !== null) {
+                req.addQuery(File(resource.toURI()))
             }
-
-            Function(functionName!!, parameters, this)
-        }.toList()
-    }
-
-    fun getFunction(name: String): Function {
-        if (functions[name] === null) {
-            throw Exception("No function defined for $name")
+        } else {
+            req.addQuery(queriesDirectory)
         }
-        return functions[name]!!
-    }
 
-    fun getQuery(path: String): Query {
-        if (queries[path] === null) {
-            throw Exception("No query defined for $path")
+        if (functionsDirectory === null) {
+            val resource = this::class.java.getResource("/sql/function")
+            if (resource !== null) {
+                req.addFunction(File(resource.toURI()))
+            }
+        } else {
+            req.addFunction(functionsDirectory)
         }
-        return queries[path]!!
+
+        return req
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/kotlin/fr/postgresjson/repository/Repository.kt b/src/main/kotlin/fr/postgresjson/repository/Repository.kt
index 0ca2428..8473c82 100644
--- a/src/main/kotlin/fr/postgresjson/repository/Repository.kt
+++ b/src/main/kotlin/fr/postgresjson/repository/Repository.kt
@@ -1,7 +1,7 @@
 package fr.postgresjson.repository
 
 import fr.postgresjson.Serializer
-import fr.postgresjson.connexion.Connection
+import fr.postgresjson.connexion.Requester
 import fr.postgresjson.entity.EntityCollection
 import fr.postgresjson.entity.EntityI
 import kotlin.reflect.KClass
@@ -12,11 +12,11 @@ interface RepositoryI<T, E : EntityI<T?>> {
 
 abstract class Repository<T, E : EntityI<T?>>(override val entityName: KClass<E>) : RepositoryI<T, E> {
 
-    abstract var connection: Connection
+    abstract var requester: Requester
     abstract fun getClassName(): String
 
     fun <T> findById(id: T): EntityI<T?>? {
-        val sql = this.connection.getQuery(entityName.toString())
+        val sql = requester.getQuery(entityName.toString())
         return when (val e = EntityCollection().get(id)) {
             null -> {
                 // TODO create Request
diff --git a/src/test/kotlin/fr/postgresjson/ConnectionTest.kt b/src/test/kotlin/fr/postgresjson/ConnectionTest.kt
index ece901e..7f1f19f 100644
--- a/src/test/kotlin/fr/postgresjson/ConnectionTest.kt
+++ b/src/test/kotlin/fr/postgresjson/ConnectionTest.kt
@@ -2,39 +2,23 @@ package fr.postgresjson
 
 import fr.postgresjson.connexion.Connection
 import fr.postgresjson.entity.IdEntity
-import org.junit.jupiter.api.*
 import org.junit.jupiter.api.Assertions.assertTrue
-import java.io.File
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.TestInstance
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
-class ConnectionTest() {
+class ConnectionTest(): TestAbstract() {
     private class ObjTest(var name: String): IdEntity()
     private class ObjTest2(var title: String, var test: ObjTest?): IdEntity()
 
     private lateinit var connection: Connection
 
-    fun getConnextion(): Connection {
-        return Connection(database = "test", username = "test", password = "test")
-    }
-
-    @BeforeAll
-    fun beforeAll() {
-        val initSQL = File(this::class.java.getResource("/fixtures/init.sql").toURI())
-        val promise = getConnextion().connect().sendQuery(initSQL.readText())
-        promise.join()
-    }
-
     @BeforeEach
     fun before() {
         connection = getConnextion()
     }
 
-    @AfterAll
-    fun afterAll() {
-        val downSQL = File(this::class.java.getResource("/fixtures/down.sql").toURI())
-        getConnextion().connect().sendQuery(downSQL.readText()).join()
-    }
-
     @Test
     fun getObject() {
         val obj: ObjTest? = connection.selectOne<Int?, ObjTest>("select to_json(a) from test a limit 1")
diff --git a/src/test/kotlin/fr/postgresjson/RequestTest.kt b/src/test/kotlin/fr/postgresjson/RequestTest.kt
index 68ad941..efc3e8e 100644
--- a/src/test/kotlin/fr/postgresjson/RequestTest.kt
+++ b/src/test/kotlin/fr/postgresjson/RequestTest.kt
@@ -1,27 +1,33 @@
 package fr.postgresjson
 
-import fr.postgresjson.connexion.Connection
+import fr.postgresjson.connexion.Requester
 import fr.postgresjson.entity.IdEntity
-import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
 import java.io.File
 
-class RequestTest {
+class RequestTest: TestAbstract() {
     class ObjTest(var name:String): IdEntity(1)
 
     @Test
-    fun getRequestFromFile() {
+    fun getQueryFromFile() {
         val resources = File(this::class.java.getResource("/sql/query").toURI())
-        val objTest: ObjTest? = Connection(queriesDirectory = resources).getQuery("Test/selectOne").selectOne()
-        assertTrue(objTest!!.id == 2)
-        assertTrue(objTest.name == "test")
+        val objTest: ObjTest? = Requester(getConnextion())
+            .addQuery(resources)
+            .getQuery("Test/selectOne")
+            .selectOne()
+        assertEquals(objTest!!.id, 2)
+        assertEquals(objTest.name, "test")
     }
 
     @Test
-    fun getRequestFromFunction() {
+    fun getFunctionFromFile() {
         val resources = File(this::class.java.getResource("/sql/function").toURI())
-        val objTest: ObjTest? = Connection(functionsDirectory = resources).getFunction("test_function").selectOne()
-        assertTrue(objTest!!.id == 2)
-        assertTrue(objTest.name == "test")
+        val objTest: ObjTest? = Requester(getConnextion())
+            .addFunction(resources)
+            .getFunction("test_function")
+            .selectOne(listOf("ploop", "plip"))
+        assertEquals(objTest!!.id, 3)
+        assertEquals(objTest.name, "test")
     }
 }
\ No newline at end of file
diff --git a/src/test/kotlin/fr/postgresjson/SerializerTest.kt b/src/test/kotlin/fr/postgresjson/SerializerTest.kt
index d957375..e8ace3e 100644
--- a/src/test/kotlin/fr/postgresjson/SerializerTest.kt
+++ b/src/test/kotlin/fr/postgresjson/SerializerTest.kt
@@ -8,7 +8,7 @@ import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
-internal class SerializerTest {
+internal class SerializerTest: TestAbstract() {
     private class ObjTest(var val1: String, var val2: Int) : IdEntity(1)
 
     private val serializer = Serializer()
diff --git a/src/test/kotlin/fr/postgresjson/TestAbstract.kt b/src/test/kotlin/fr/postgresjson/TestAbstract.kt
new file mode 100644
index 0000000..2fbca6b
--- /dev/null
+++ b/src/test/kotlin/fr/postgresjson/TestAbstract.kt
@@ -0,0 +1,28 @@
+package fr.postgresjson
+
+import fr.postgresjson.connexion.Connection
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import org.junit.jupiter.api.TestInstance.Lifecycle.PER_CLASS
+import java.io.File
+
+@TestInstance(PER_CLASS)
+abstract class TestAbstract {
+    protected fun getConnextion(): Connection {
+        return Connection(database = "test", username = "test", password = "test")
+    }
+
+    @BeforeAll
+    fun beforeAll() {
+        val initSQL = File(this::class.java.getResource("/fixtures/init.sql").toURI())
+        val promise = getConnextion().connect().sendQuery(initSQL.readText())
+        promise.join()
+    }
+
+    @AfterAll
+    fun afterAll() {
+        val downSQL = File(this::class.java.getResource("/fixtures/down.sql").toURI())
+        getConnextion().connect().sendQuery(downSQL.readText()).join()
+    }
+}
\ No newline at end of file
diff --git a/src/test/resources/fixtures/init.sql b/src/test/resources/fixtures/init.sql
index 4b226a3..2e4699f 100644
--- a/src/test/resources/fixtures/init.sql
+++ b/src/test/resources/fixtures/init.sql
@@ -24,3 +24,12 @@ INSERT INTO test (id, name) VALUES (1, 'plop') ON CONFLICT DO NOTHING;
 INSERT INTO test2 (id, title, test_id) VALUES (1, 'plop', 1) ON CONFLICT DO NOTHING;
 INSERT INTO test2 (id, title, test_id) VALUES (2, 'plip', 1) ON CONFLICT DO NOTHING;
 INSERT INTO test2 (id, title, test_id) VALUES (3, 'ttt', null) ON CONFLICT DO NOTHING;
+
+CREATE OR REPLACE FUNCTION test_function (name text default 'plop', IN hi text default 'hello', out result json)
+    LANGUAGE plpgsql
+AS
+$$
+BEGIN
+    result = json_build_object('id', 3, 'name', 'test');
+END;
+$$
diff --git a/src/test/resources/sql/function/Test/function_test.sql b/src/test/resources/sql/function/Test/function_test.sql
index e79bc63..8e81032 100644
--- a/src/test/resources/sql/function/Test/function_test.sql
+++ b/src/test/resources/sql/function/Test/function_test.sql
@@ -1,8 +1,8 @@
-CREATE OR REPLACE FUNCTION test_function (name text, IN hi text default 'hello', out result json)
+CREATE OR REPLACE FUNCTION test_function (name text default 'plop', IN hi text default 'hello', out result json)
 LANGUAGE plpgsql
 AS
 $$
 BEGIN
-    result = json_build_object('id', 2, 'name', 'test');
+    result = json_build_object('id', 3, 'name', 'test');
 END;
 $$
\ No newline at end of file