From: eileen <emcnaughton@wikimedia.org>
Date: Wed, 3 Feb 2016 00:10:57 +0000 (+1300)
Subject: CRM-17775 Add safe function for dropping indexes
X-Git-Url: https://vcs.fsf.org/?a=commitdiff_plain;h=50969d52de4cbd990fd6e2cefe73917d33efd2bd;p=civicrm-core.git

CRM-17775 Add safe function for dropping indexes
---

diff --git a/CRM/Core/BAO/SchemaHandler.php b/CRM/Core/BAO/SchemaHandler.php
index a5be485760..a92572c03a 100644
--- a/CRM/Core/BAO/SchemaHandler.php
+++ b/CRM/Core/BAO/SchemaHandler.php
@@ -373,7 +373,7 @@ ALTER TABLE {$tableName}
    */
   public static function dropColumn($tableName, $columnName) {
     $sql = "ALTER TABLE $tableName DROP COLUMN $columnName";
-    $dao = CRM_Core_DAO::executeQuery($sql);
+    CRM_Core_DAO::executeQuery($sql);
   }
 
   /**
@@ -415,7 +415,7 @@ ADD UNIQUE INDEX `unique_entity_id` ( `entity_id` )";
    * @param string $createIndexPrefix
    * @param array $substrLenghts
    */
-  public static function createIndexes(&$tables, $createIndexPrefix = 'index', $substrLenghts = array()) {
+  public static function createIndexes($tables, $createIndexPrefix = 'index', $substrLenghts = array()) {
     $queries = array();
     $domain = new CRM_Core_DAO_Domain();
     $domain->find(TRUE);
@@ -491,6 +491,18 @@ ADD UNIQUE INDEX `unique_entity_id` ( `entity_id` )";
     }
   }
 
+  /**
+   * Drop an index if one by that name exists.
+   *
+   * @param string $tableName
+   * @param string $indexName
+   */
+  public static function dropIndexIfExists($tableName, $indexName) {
+    if (self::checkIfIndexExists($tableName, $indexName)) {
+      CRM_Core_DAO::executeQuery("DROP INDEX $indexName ON $tableName");
+    }
+  }
+
   /**
    * @param int $customFieldID
    * @param string $tableName
@@ -548,4 +560,23 @@ MODIFY      {$columnName} varchar( $length )
     }
   }
 
+  /**
+   * Check if the table has an index matching the name.
+   *
+   * @param string $tableName
+   * @param array $indexName
+   *
+   * @return \CRM_Core_DAO|object
+   */
+  public static function checkIfIndexExists($tableName, $indexName) {
+    $result = CRM_Core_DAO::executeQuery(
+      "SHOW INDEX FROM $tableName WHERE key_name = %1 AND seq_in_index = 1",
+      array(1 => array($indexName, 'String'))
+    );
+    if ($result->fetch()) {
+      return TRUE;
+    }
+    return FALSE;
+  }
+
 }
diff --git a/tests/phpunit/CRM/Core/BAO/SchemaHandlerTest.php b/tests/phpunit/CRM/Core/BAO/SchemaHandlerTest.php
index 26ec47fc21..fda5c6ae10 100644
--- a/tests/phpunit/CRM/Core/BAO/SchemaHandlerTest.php
+++ b/tests/phpunit/CRM/Core/BAO/SchemaHandlerTest.php
@@ -89,4 +89,36 @@ class CRM_Core_BAO_SchemaHandlerTest extends CiviUnitTestCase {
     $this->assertEquals(2, $weightCount);
   }
 
+  /**
+   * Test the drop index if exists function for a non-existent index.
+   */
+  public function testCHeckIndexNotExists() {
+    $this->assertFalse(CRM_Core_BAO_SchemaHandler::checkIfIndexExists('civicrm_contact', 'magic_button'));
+  }
+
+  /**
+   * Test the drop index if exists function for a non-existent index.
+   */
+  public function testCHeckIndexExists() {
+    $this->assertTrue(CRM_Core_BAO_SchemaHandler::checkIfIndexExists('civicrm_contact', 'index_hash'));
+  }
+
+  /**
+   * Test the drop index if exists function for a non-existent index.
+   */
+  public function testDropIndexNoneExists() {
+    CRM_Core_BAO_SchemaHandler::dropIndexIfExists('civicrm_contact', 'magic_button');
+  }
+
+  /**
+   * Test the drop index if exists function.
+   */
+  public function testDropIndexExists() {
+    CRM_Core_BAO_SchemaHandler::dropIndexIfExists('civicrm_contact', 'index_hash');
+    $this->assertFalse(CRM_Core_BAO_SchemaHandler::checkIfIndexExists('civicrm_contact', 'index_hash'));
+
+    // Recreate it to clean up after the test.
+    CRM_Core_BAO_SchemaHandler::createIndexes(array('civicrm_contact' => array('hash')));
+  }
+
 }