diff --git a/modules/field/modules/field_sql_storage/field_sql_storage.module b/modules/field/modules/field_sql_storage/field_sql_storage.module
index 93f2077..7ab4ee5 100644
--- a/modules/field/modules/field_sql_storage/field_sql_storage.module
+++ b/modules/field/modules/field_sql_storage/field_sql_storage.module
@@ -65,6 +65,49 @@ function _field_sql_storage_revision_tablename($field) {
 }
 
 /**
+ * Generates a table alias for a field data table.
+ *
+ * The table alias is unique for each unique combination of field name
+ * (represented by $tablename), delta_group and language_group.
+ *
+ * @param $tablename
+ *   The name of the data table for this field.
+ * @param $field_key
+ *   The numeric key of this field in this query.
+ * @param $query
+ *   The EntityFieldQuery that is executed.
+ *
+ * @return
+ *   A string containing the generated table alias.
+ */
+function _field_sql_storage_tablealias($tablename, $field_key, EntityFieldQuery $query) {
+  // No conditions present: use a unique alias.
+  if (empty($query->fieldConditions[$field_key])) {
+    return $tablename . $field_key;
+  }
+
+  // Find the delta and language condition values and append them to the alias.
+  $condition = $query->fieldConditions[$field_key];
+  $alias = $tablename;
+  $has_group_conditions = FALSE;
+
+  foreach (array('delta', 'language') as $column) {
+    if (isset($condition[$column . '_group'])) {
+      $alias .= '_' . $column . '_' . $condition[$column . '_group'];
+      $has_group_conditions = TRUE;
+    }
+  }
+
+  // Return the alias when it has delta/language group conditions.
+  if ($has_group_conditions) {
+    return $alias;
+  }
+
+  // Return a unique alias in other cases.
+  return $tablename . $field_key;
+}
+
+/**
  * Generate a column name for a field data table.
  *
  * @param $name
@@ -504,17 +547,21 @@ function field_sql_storage_field_storage_query(EntityFieldQuery $query) {
     $id_key = 'revision_id';
   }
   $table_aliases = array();
+  $query_tables = NULL;
   // Add tables for the fields used.
   foreach ($query->fields as $key => $field) {
     $tablename = $tablename_function($field);
-    // Every field needs a new table.
-    $table_alias = $tablename . $key;
+    $table_alias = _field_sql_storage_tablealias($tablename, $key, $query);
     $table_aliases[$key] = $table_alias;
     if ($key) {
-      $select_query->join($tablename, $table_alias, "$table_alias.entity_type = $field_base_table.entity_type AND $table_alias.$id_key = $field_base_table.$id_key");
+      if (!isset($query_tables[$table_alias])) {
+        $select_query->join($tablename, $table_alias, "$table_alias.entity_type = $field_base_table.entity_type AND $table_alias.$id_key = $field_base_table.$id_key");
+      }
     }
     else {
       $select_query = db_select($tablename, $table_alias);
+      // Store a reference to the list of joined tables.
+      $query_tables =& $select_query->getTables();
       // Allow queries internal to the Field API to opt out of the access
       // check, for situations where the query's results should not depend on
       // the access grants for the current user.
diff --git a/modules/field/modules/field_sql_storage/field_sql_storage.test b/modules/field/modules/field_sql_storage/field_sql_storage.test
index 12c54ba..1d160a0 100644
--- a/modules/field/modules/field_sql_storage/field_sql_storage.test
+++ b/modules/field/modules/field_sql_storage/field_sql_storage.test
@@ -438,4 +438,146 @@ class FieldSqlStorageTestCase extends DrupalWebTestCase {
     $this->assertEqual($foreign_key['table'], $foreign_key_name, 'Foreign key table name preserved in the schema');
     $this->assertEqual($foreign_key['columns'][$foreign_key_column], 'id', 'Foreign key column name preserved in the schema');
   }
+
+  /**
+   * Test handling multiple conditions on one column of a field.
+   *
+   * Tests both the result and the complexity of the query.
+   */
+  function testFieldSqlStorageMultipleConditionsSameColumn() {
+    $entity = field_test_create_stub_entity(NULL, NULL);
+    $entity->{$this->field_name}[LANGUAGE_NONE][0] = array('value' => 1);
+    field_test_entity_save($entity);
+
+    $entity = field_test_create_stub_entity(NULL, NULL);
+    $entity->{$this->field_name}[LANGUAGE_NONE][0] = array('value' => 2);
+    field_test_entity_save($entity);
+
+    $entity = field_test_create_stub_entity(NULL, NULL);
+    $entity->{$this->field_name}[LANGUAGE_NONE][0] = array('value' => 3);
+    field_test_entity_save($entity);
+
+    $query = new EntityFieldQuery();
+    // The tag causes field_sql_storage_query_test_alter() to be invoked so the query can be tested.
+    $query->addTag('test');
+    $query->entityCondition('entity_type', 'test_entity');
+    $query->entityCondition('bundle', 'test_bundle');
+    $query->fieldCondition($this->field_name, 'value', 1, '<>', 0, LANGUAGE_NONE);
+    $query->fieldCondition($this->field_name, 'value', 2, '<>', 0, LANGUAGE_NONE);
+    $result = field_sql_storage_field_storage_query($query);
+
+    // Test the results.
+    $this->assertEqual(1, count($result), format_string('One result should be returned, got @count', array('@count' => count($result))));
+
+    // Test the complexity of the query.
+    $query = $GLOBALS['test_query'];
+    $this->assertNotNull($query, 'Precondition: the query should be available');
+    $tables = $query->getTables();
+    $this->assertEqual(1, count($tables), 'The query contains just one table.');
+  }
+
+  /**
+   * Test handling multiple conditions on multiple columns of one field.
+   *
+   * Tests both the result and the complexity of the query.
+   */
+  function testFieldSqlStorageMultipleConditionsDifferentColumns() {
+    // Create the multi-column shape field
+    $field_name = strtolower($this->randomName());
+    $field = array('field_name' => $field_name, 'type' => 'shape', 'cardinality' => 4);
+    $field = field_create_field($field);
+    $instance = array(
+      'field_name' => $field_name,
+      'entity_type' => 'test_entity',
+      'bundle' => 'test_bundle'
+    );
+    $instance = field_create_instance($instance);
+
+    $entity = field_test_create_stub_entity(NULL, NULL);
+    $entity->{$field_name}[LANGUAGE_NONE][0] = array('shape' => 'A', 'color' => 'X');
+    field_test_entity_save($entity);
+
+    $entity = field_test_create_stub_entity(NULL, NULL);
+    $entity->{$field_name}[LANGUAGE_NONE][0] = array('shape' => 'B', 'color' => 'X');
+    field_test_entity_save($entity);
+
+    $entity = field_test_create_stub_entity(NULL, NULL);
+    $entity->{$field_name}[LANGUAGE_NONE][0] = array('shape' => 'A', 'color' => 'Y');
+    field_test_entity_save($entity);
+
+    $query = new EntityFieldQuery();
+    // The tag causes field_sql_storage_query_test_alter() to be invoked so the SQL query object can be tested.
+    $query->addTag('test');
+    $query->entityCondition('entity_type', 'test_entity');
+    $query->entityCondition('bundle', 'test_bundle');
+    $query->fieldCondition($field_name, 'shape', 'B', '=', 'something', LANGUAGE_NONE);
+    $query->fieldCondition($field_name, 'color', 'X', '=', 'something', LANGUAGE_NONE);
+    $result = field_sql_storage_field_storage_query($query);
+
+    // Test the results.
+    $this->assertEqual(1, count($result), format_string('One result should be returned, got @count', array('@count' => count($result))));
+
+    // Test the complexity of the query.
+    $query = $GLOBALS['test_query'];
+    $this->assertNotNull($query, 'Precondition: the query should be available');
+    $tables = $query->getTables();
+    $this->assertEqual(1, count($tables), 'The query contains just one table.');
+  }
+
+  /**
+   * Test handling multiple conditions on multiple columns of one field for multiple languages.
+   *
+   * Tests both the result and the complexity of the query.
+   */
+  function testFieldSqlStorageMultipleConditionsDifferentColumnsMultipleLanguages() {
+    field_test_entity_info_translatable('test_entity', TRUE);
+
+    // Create the multi-column shape field
+    $field_name = strtolower($this->randomName());
+    $field = array('field_name' => $field_name, 'type' => 'shape', 'cardinality' => 4, 'translatable' => TRUE);
+    $field = field_create_field($field);
+    $instance = array(
+      'field_name' => $field_name,
+      'entity_type' => 'test_entity',
+      'bundle' => 'test_bundle',
+      'settings' => array(
+        // Prevent warning from field_test_field_load().
+        'test_hook_field_load' => FALSE,
+      ),
+    );
+    $instance = field_create_instance($instance);
+
+    $entity = field_test_create_stub_entity(NULL, NULL);
+    $entity->{$field_name}[LANGUAGE_NONE][0] = array('shape' => 'A', 'color' => 'X');
+    $entity->{$field_name}['en'][0] = array('shape' => 'B', 'color' => 'Y');
+    field_test_entity_save($entity);
+    $entity = field_test_entity_test_load($entity->ftid);
+
+    $query = new EntityFieldQuery();
+    // The tag causes field_sql_storage_query_test_alter() to be invoked so the SQL query object can be tested.
+    $query->addTag('test');
+    $query->entityCondition('entity_type', 'test_entity');
+    $query->entityCondition('bundle', 'test_bundle');
+    $query->fieldCondition($field_name, 'color', 'X', '=', NULL, LANGUAGE_NONE);
+    $query->fieldCondition($field_name, 'shape', 'B', '=', NULL, 'en');
+    $result = field_sql_storage_field_storage_query($query);
+
+    // Test the results.
+    $this->assertEqual(1, count($result), format_string('One result should be returned, got @count', array('@count' => count($result))));
+
+    // Test the complexity of the query.
+    $query = $GLOBALS['test_query'];
+    $this->assertNotNull($query, 'Precondition: the query should be available');
+    $tables = $query->getTables();
+    $this->assertEqual(2, count($tables), 'The query contains two tables.');
+  }
+}
+
+/**
+ * Implements hook_query_TAG_alter().
+ *
+ * Saves the query in a global variable to allow tests.
+ */
+function field_sql_storage_query_test_alter($query) {
+  $GLOBALS['test_query'] = $query;
 }