Issue #2875679 by mondrake, daffie: BasicSyntaxTest::testConcatFields fails with contrib driver

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

@@ -29,15 +29,22 @@ class BasicSyntaxTest extends DatabaseTestBase {
 
   /**
    * Tests string concatenation with field values.
+   *
+   * We use 'job' and 'age' fields from the {test} table. Using the 'name' field
+   * for concatenation causes issues with custom or contrib database drivers,
+   * since its type 'varchar_ascii' may lead to using field-level collations not
+   * compatible with the other fields.
    */
   public function testConcatFields() {
-    $result = db_query('SELECT CONCAT(:a1, CONCAT(name, CONCAT(:a2, CONCAT(age, :a3)))) FROM {test} WHERE age = :age', [
-      ':a1' => 'The age of ',
-      ':a2' => ' is ',
-      ':a3' => '.',
-      ':age' => 25,
-    ]);
-    $this->assertIdentical($result->fetchField(), 'The age of John is 25.', 'Field CONCAT works.');
+    $result = $this->connection->query(
+      'SELECT CONCAT(:a1, CONCAT(job, CONCAT(:a2, CONCAT(age, :a3)))) FROM {test} WHERE age = :age', [
+        ':a1' => 'The age of ',
+        ':a2' => ' is ',
+        ':a3' => '.',
+        ':age' => 25,
+      ]
+    );
+    $this->assertSame('The age of Singer is 25.', $result->fetchField(), 'Field CONCAT works.');
   }
 
   /**