Issue #3120892 by Kumar Kundan, ravi.shankar, julienjoye, daffie: Replicate SQL LEAST() in SQLite

core/lib/Drupal/Core/Database/Driver/sqlite/Connection.php

@@ -133,6 +133,7 @@ class Connection extends DatabaseConnection {
     // Create functions needed by SQLite.
     $pdo->sqliteCreateFunction('if', [__CLASS__, 'sqlFunctionIf']);
     $pdo->sqliteCreateFunction('greatest', [__CLASS__, 'sqlFunctionGreatest']);
+    $pdo->sqliteCreateFunction('least', [__CLASS__, 'sqlFunctionLeast']);
     $pdo->sqliteCreateFunction('pow', 'pow', 2);
     $pdo->sqliteCreateFunction('exp', 'exp', 1);
     $pdo->sqliteCreateFunction('length', 'strlen', 1);
@@ -239,6 +240,16 @@ class Connection extends DatabaseConnection {
     }
   }
 
+  /**
+   * SQLite compatibility implementation for the LEAST() SQL function.
+   */
+  public static function sqlFunctionLeast() {
+    // Remove all NULL, FALSE and empty strings values but leaves 0 (zero) values.
+    $values = array_filter(func_get_args(), 'strlen');
+
+    return count($values) < 1 ? NULL : min($values);
+  }
+
   /**
    * SQLite compatibility implementation for the CONCAT() SQL function.
    */

core/tests/Drupal/KernelTests/Core/Database/SelectLeastTest.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Drupal\KernelTests\Core\Database;
+
+/**
+ * Tests the SQL LEAST operator.
+ *
+ * @group Database
+ */
+class SelectLeastTest extends DatabaseTestBase {
+
+  /**
+   * Tests the SQL LEAST operator.
+   *
+   * @dataProvider selectLeastProvider
+   */
+  public function testSelectLeast($values, $expected) {
+    $least = $this->connection->query("SELECT LEAST(:values[])", [':values[]' => $values])->fetchField();
+    $this->assertEquals($expected, $least);
+  }
+
+  public function selectLeastProvider() {
+    return [
+      [[1, 2, 3, 4, 5, 6], 1],
+      [['A', 'B', 'C', 'NULL', 'F'], 'A'],
+      [['NULL', 'NULL'], 'NULL'],
+      [['TRUE', 'FALSE'], 'FALSE'],
+      [['A', 'B', 'C', 'NULL'], 'A'],
+    ];
+  }
+
+}