4 files changed, 11 insertions, 7 deletions
diff --git a/includes/database/mysql/query.inc b/includes/database/mysql/query.inc
index fa698d90c..d3d2d9eec 100644
--- a/includes/database/mysql/query.inc
+++ b/includes/database/mysql/query.inc
@@ -51,7 +51,8 @@ class InsertQuery_mysql extends InsertQuery {
     // If we're selecting from a SelectQuery, finish building the query and
     // pass it back, as any remaining options are irrelevant.
     if (!empty($this->fromQuery)) {
-      return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') ' . $this->fromQuery;
+      $insert_fields_string = $insert_fields ? ' (' . implode(', ', $insert_fields) . ') ' : ' ';
+      return $comments . 'INSERT INTO {' . $this->table . '}' . $insert_fields_string . $this->fromQuery;
     }
 
     $query = $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';
diff --git a/includes/database/pgsql/query.inc b/includes/database/pgsql/query.inc
index f3783a9ca..9902b1643 100644
--- a/includes/database/pgsql/query.inc
+++ b/includes/database/pgsql/query.inc
@@ -112,7 +112,8 @@ class InsertQuery_pgsql extends InsertQuery {
     // If we're selecting from a SelectQuery, finish building the query and
     // pass it back, as any remaining options are irrelevant.
     if (!empty($this->fromQuery)) {
-      return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') ' . $this->fromQuery;
+      $insert_fields_string = $insert_fields ? ' (' . implode(', ', $insert_fields) . ') ' : ' ';
+      return $comments . 'INSERT INTO {' . $this->table . '}' . $insert_fields_string . $this->fromQuery;
     }
 
     $query = $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';
diff --git a/includes/database/query.inc b/includes/database/query.inc
index 66495273e..ce242beb7 100644
--- a/includes/database/query.inc
+++ b/includes/database/query.inc
@@ -710,10 +710,11 @@ class InsertQuery extends Query {
       // first call to fields() does have an effect.
       $this->fields(array_merge(array_keys($this->fromQuery->getFields()), array_keys($this->fromQuery->getExpressions())));
     }
-
-    // Don't execute query without fields.
-    if (count($this->insertFields) + count($this->defaultFields) == 0) {
-      throw new NoFieldsException('There are no fields available to insert with.');
+    else {
+      // Don't execute query without fields.
+      if (count($this->insertFields) + count($this->defaultFields) == 0) {
+        throw new NoFieldsException('There are no fields available to insert with.');
+      }
     }
 
     // If no values have been added, silently ignore this query. This can happen
diff --git a/includes/database/sqlite/query.inc b/includes/database/sqlite/query.inc
index 1bf609db1..1c6289bd7 100644
--- a/includes/database/sqlite/query.inc
+++ b/includes/database/sqlite/query.inc
@@ -41,7 +41,8 @@ class InsertQuery_sqlite extends InsertQuery {
     // If we're selecting from a SelectQuery, finish building the query and
     // pass it back, as any remaining options are irrelevant.
     if (!empty($this->fromQuery)) {
-      return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $this->insertFields) . ') ' . $this->fromQuery;
+      $insert_fields_string = $this->insertFields ? ' (' . implode(', ', $this->insertFields) . ') ' : ' ';
+      return $comments . 'INSERT INTO {' . $this->table . '}' . $insert_fields_string . $this->fromQuery;
     }
 
     return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $this->insertFields) . ') VALUES (' . implode(', ', $placeholders) . ')';