implements new MysqliDb::insertMulti() Method

- MysqliDb::insertMulti() requires at least a table-name and
two-dimensional array containing the data-sets
- the third parameter $dataKeys can contain an array, setting|overriding
the table column names in the data-sets
- removes some unnecessary linebreaks and comments
- fixes typo
- adds insertMulti() to Readme
- adds MysqliDB::insertMulti() insertion tests
- removes whitespace changes

MysqliDb.php

@@ -679,6 +679,48 @@ class MysqliDb
         return $this->_buildInsert($tableName, $insertData, 'INSERT');
     }
 
+    /**
+     * Insert method to add several rows at once
+     *
+     * @param string $tableName The name of the table.
+     * @param array $multiInsertData Two-dimensinal Data-array containing information for inserting into the DB.
+     * @param array $dataKeys Optinal Table Key names, if not set in insertDataSet.
+     *
+     * @return bool|array Boolean indicating the insertion failed (false), else return id-array ([int])
+     */
+    public function insertMulti($tableName, array $multiInsertData, array $dataKeys = null)
+    {
+        // only auto-commit our inserts, if no transaction is currently running
+        $autoCommit = (isset($this->_transaction_in_progress) ? !$this->_transaction_in_progress : true);
+        $ids = [];
+
+        if($autoCommit) {
+            $this->startTransaction();
+        }
+
+        foreach ($multiInsertData as $insertData) {
+            if($dataKeys !== null) {
+                // apply column-names if given, else assume they're already given in the data
+                $insertData = array_combine($dataKeys, $insertData);
+            }
+
+            $id = $this->insert($tableName, $insertData);
+            if(!$id) {
+                if($autoCommit) {
+                    $this->rollback();
+                }
+                return false;
+            }
+            $ids[] = $id;
+        }
+
+        if($autoCommit) {
+            $this->commit();
+        }
+
+        return $ids;
+    }
+
     /**
      * Replace method to add new row
      *

readme.md

@@ -144,6 +144,43 @@ $db->onDuplicate($updateColumns, $lastInsertId);
 $id = $db->insert ('users', $data);
 ```
 
+Insert multiple datasets at once
+```php
+$data = Array(
+    Array ("login" => "admin",
+        "firstName" => "John",
+        "lastName" => 'Doe'
+    ),
+    Array ("login" => "other",
+        "firstName" => "Another",
+        "lastName" => 'User',
+        "password" => "very_cool_hash"
+    )
+);
+$ids = $db->insertMulti('users', $data);
+if(!$ids) {
+    echo 'insert failed: ' . $db->getLastError();
+} else {
+    echo 'new users inserted with following id\'s: ' . implode(', ', $ids);
+}
+```
+
+If all datasets only have the same keys, it can be simplified
+```php
+$data = Array(
+    Array ("admin", "John", "Doe"),
+    Array ("other", "Another", "User")
+);
+$keys = Array("login", "firstName", "lastName");
+
+$ids = $db->insertMulti('users', $data, $keys);
+if(!$ids) {
+    echo 'insert failed: ' . $db->getLastError();
+} else {
+    echo 'new users inserted with following id\'s: ' . implode(', ', $ids);
+}
+```
+
 ### Replace Query
 <a href='https://dev.mysql.com/doc/refman/5.0/en/replace.html'>Replace()</a> method implements same API as insert();
 

tests/mysqliDbTests.php

@@ -396,8 +396,8 @@ if ($c != 3) {
 }
 unset ($cnt);
 
-$data = $db->get('users');
-if (count($data) != 3) {
+$users = $db->get('users');
+if (count($users) != 3) {
     echo "copy with subquery data count failed";
     exit;
 }
@@ -444,6 +444,47 @@ if (key ($result) != 1 && !is_object ($result[1])) {
     exit;
 }
 
+$expectedIDs = [
+    'users' => [5, 6, 7],
+    'products' => [6,7,8,9,10],
+];
+
+// multi-insert test with autoincrement
+foreach ($data as $name => $datas) {
+
+    // remove previous entries to ensure avoiding PRIMARY-KEY collisions here
+    $db->delete($name);
+
+    // actual insertion test
+    $ids = $db->insertMulti($name, $datas);
+
+    // check results
+    if(!$ids) {
+        echo "failed to multi-insert: ".$db->getLastQuery() ."\n". $db->getLastError();
+        exit;
+    } elseif($ids !== $expectedIDs[$name]) {
+        pretty_print($ids);
+        echo "multi-insert succeeded, but unexpected id's: ".$db->getLastQuery() ."\n". $db->getLastError();
+        exit;
+    }
+}
+
+// skip last user here, since it has other keys than the others
+unset($data['users'][2]);
+
+// multi-insert test with autoincrement and overriding column-names
+foreach ($data as $name => $datas) {
+
+    // remove previous entries to ensure avoiding PRIMARY-KEY collisions here
+    $db->delete($name);
+
+    // actual insertion test
+    if(!$db->insertMulti($name, $datas, array_keys($datas[0]))) {
+        echo "failed to multi-insert: ".$db->getLastQuery() ."\n". $db->getLastError();
+        exit;
+    }
+}
+
 ///
 //TODO: insert test
 $db->delete("users");