diff --git a/tests/cases/Database/Base.php b/tests/cases/Database/AbstractTest.php
similarity index 98%
rename from tests/cases/Database/Base.php
rename to tests/cases/Database/AbstractTest.php
index f9a92f4..1bccfde 100644
--- a/tests/cases/Database/Base.php
+++ b/tests/cases/Database/AbstractTest.php
@@ -10,7 +10,7 @@ use JKingWeb\Arsse\Test\Database;
 use JKingWeb\Arsse\Arsse;
 use JKingWeb\Arsse\User;
 
-abstract class Base extends \JKingWeb\Arsse\Test\AbstractTest {
+abstract class AbstractTest extends \JKingWeb\Arsse\Test\AbstractTest {
     use SeriesMiscellany;
     use SeriesMeta;
     use SeriesUser;
diff --git a/tests/cases/Database/TestDatabase.php b/tests/cases/Database/TestDatabase.php
new file mode 100644
index 0000000..bd07e46
--- /dev/null
+++ b/tests/cases/Database/TestDatabase.php
@@ -0,0 +1,58 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\TestCase\Database;
+
+use JKingWeb\Arsse\Database;
+
+/** @covers \JKingWeb\Arsse\Database */
+class TestDatabase extends \JKingWeb\Arsse\Test\AbstractTest {
+    static $db = null;
+    
+    public static function setUpBeforeClass() {
+        self::clearData();
+        self::setConf();
+        self::$db = \Phake::makeVisible(\Phake::partialMock(Database::class));
+    }
+
+    public static function tearDownAfterClass() {
+        self::$db = null;
+        self::clearData();
+    }
+
+    /** @dataProvider provideInClauses */
+    public function testGenerateInClause(string $clause, array $values, array $inV, string $inT) {
+        $types = array_fill(0, sizeof($values), $inT);
+        $exp = [$clause, $types, $values];
+        $this->assertSame($exp, self::$db->generateIn($inV, $inT));
+    }
+
+    public function provideInClauses() {
+        $l = Database::LIMIT_SET_SIZE + 1;
+        $strings = array_fill(0, $l, "");
+        $ints = range(1, $l);
+        $longString = str_repeat("0", Database::LIMIT_SET_STRING_LENGTH + 1);
+        $params = implode(",", array_fill(0, $l, "?"));
+        $intList = implode(",", $ints);
+        $stringList = implode(",", array_fill(0, $l, "''"));
+        return [
+            ["null",               [],            [],                                   "str"],
+            ["?",                  [1],           [1],                                  "int"],
+            ["?",                  ["1"],         ["1"],                                "int"],
+            ["?,?",                [null, null],  [null, null],                         "str"],
+            ["null",               [],            array_fill(0, $l, null),              "str"],
+            ["$intList",           [],            $ints,                                "int"],
+            ["$intList,".($l+1),   [],            array_merge($ints, [$l+1]),           "int"],
+            ["$intList,0",         [],            array_merge($ints, ["OOK"]),          "int"],
+            ["$intList",           [],            array_merge($ints, [null]),           "int"],
+            ["$stringList,''",     [],            array_merge($strings, [""]),          "str"],
+            ["$stringList",        [],            array_merge($strings, [null]),        "str"],
+            ["$stringList,?",      [$longString], array_merge($strings, [$longString]), "str"],
+            ["$stringList,'A''s'", [],            array_merge($strings, ["A's"]),       "str"],
+            ["$params",            $ints,         $ints,                                "bool"],
+        ];
+    }
+}
diff --git a/tests/cases/Db/MySQL/TestDatabase.php b/tests/cases/Db/MySQL/TestDatabase.php
index eaf19bb..4364170 100644
--- a/tests/cases/Db/MySQL/TestDatabase.php
+++ b/tests/cases/Db/MySQL/TestDatabase.php
@@ -12,7 +12,7 @@ namespace JKingWeb\Arsse\TestCase\Db\MySQL;
  * @covers \JKingWeb\Arsse\Database<extended>
  * @covers \JKingWeb\Arsse\Misc\Query<extended>
  */
-class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\Base {
+class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\AbstractTest {
     use \JKingWeb\Arsse\Test\DatabaseDrivers\MySQL;
 
     protected function nextID(string $table): int {
diff --git a/tests/cases/Db/MySQLPDO/TestDatabase.php b/tests/cases/Db/MySQLPDO/TestDatabase.php
index 1b12566..6a7550e 100644
--- a/tests/cases/Db/MySQLPDO/TestDatabase.php
+++ b/tests/cases/Db/MySQLPDO/TestDatabase.php
@@ -13,7 +13,7 @@ namespace JKingWeb\Arsse\TestCase\Db\MySQLPDO;
  * @covers \JKingWeb\Arsse\Database<extended>
  * @covers \JKingWeb\Arsse\Misc\Query<extended>
  */
-class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\Base {
+class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\AbstractTest {
     use \JKingWeb\Arsse\Test\DatabaseDrivers\MySQLPDO;
 
     protected function nextID(string $table): int {
diff --git a/tests/cases/Db/PostgreSQL/TestDatabase.php b/tests/cases/Db/PostgreSQL/TestDatabase.php
index f2277af..9fda4d9 100644
--- a/tests/cases/Db/PostgreSQL/TestDatabase.php
+++ b/tests/cases/Db/PostgreSQL/TestDatabase.php
@@ -12,7 +12,7 @@ namespace JKingWeb\Arsse\TestCase\Db\PostgreSQL;
  * @covers \JKingWeb\Arsse\Database<extended>
  * @covers \JKingWeb\Arsse\Misc\Query<extended>
  */
-class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\Base {
+class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\AbstractTest {
     use \JKingWeb\Arsse\Test\DatabaseDrivers\PostgreSQL;
 
     protected function nextID(string $table): int {
diff --git a/tests/cases/Db/PostgreSQLPDO/TestDatabase.php b/tests/cases/Db/PostgreSQLPDO/TestDatabase.php
index 810c13c..6f8ef2a 100644
--- a/tests/cases/Db/PostgreSQLPDO/TestDatabase.php
+++ b/tests/cases/Db/PostgreSQLPDO/TestDatabase.php
@@ -13,7 +13,7 @@ namespace JKingWeb\Arsse\TestCase\Db\PostgreSQLPDO;
  * @covers \JKingWeb\Arsse\Database<extended>
  * @covers \JKingWeb\Arsse\Misc\Query<extended>
  */
-class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\Base {
+class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\AbstractTest {
     use \JKingWeb\Arsse\Test\DatabaseDrivers\PostgreSQLPDO;
 
     protected function nextID(string $table): int {
diff --git a/tests/cases/Db/SQLite3/TestDatabase.php b/tests/cases/Db/SQLite3/TestDatabase.php
index 3fb1139..eab0970 100644
--- a/tests/cases/Db/SQLite3/TestDatabase.php
+++ b/tests/cases/Db/SQLite3/TestDatabase.php
@@ -11,7 +11,7 @@ namespace JKingWeb\Arsse\TestCase\Db\SQLite3;
  * @covers \JKingWeb\Arsse\Database<extended>
  * @covers \JKingWeb\Arsse\Misc\Query<extended>
  */
-class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\Base {
+class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\AbstractTest {
     use \JKingWeb\Arsse\Test\DatabaseDrivers\SQLite3;
 
     protected function nextID(string $table): int {
diff --git a/tests/cases/Db/SQLite3PDO/TestDatabase.php b/tests/cases/Db/SQLite3PDO/TestDatabase.php
index 504775e..079bcc1 100644
--- a/tests/cases/Db/SQLite3PDO/TestDatabase.php
+++ b/tests/cases/Db/SQLite3PDO/TestDatabase.php
@@ -10,7 +10,7 @@ namespace JKingWeb\Arsse\TestCase\Db\SQLite3PDO;
  * @covers \JKingWeb\Arsse\Database<extended>
  * @covers \JKingWeb\Arsse\Misc\Query<extended>
  */
-class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\Base {
+class TestDatabase extends \JKingWeb\Arsse\TestCase\Database\AbstractTest {
     use \JKingWeb\Arsse\Test\DatabaseDrivers\SQLite3PDO;
 
     protected function nextID(string $table): int {
diff --git a/tests/phpunit.dist.xml b/tests/phpunit.dist.xml
index cae3734..5489f94 100644
--- a/tests/phpunit.dist.xml
+++ b/tests/phpunit.dist.xml
@@ -98,6 +98,7 @@
         <file>cases/Db/MySQLPDO/TestUpdate.php</file>
     </testsuite>
     <testsuite name="Database functions">
+        <file>cases/Database/TestDatabase.php</file>
         <file>cases/Db/SQLite3/TestDatabase.php</file>
         <file>cases/Db/SQLite3PDO/TestDatabase.php</file>
         <file>cases/Db/PostgreSQL/TestDatabase.php</file>