Added Connection::useMaster() and refactored code.

framework/db/Command.php

@@ -69,7 +69,7 @@ class Command extends \yii\base\Component
     /**
      * @var array the parameters (name => value) that are bound to the current PDO statement.
      * This property is maintained by methods such as [[bindValue()]]. It is mainly provided for logging purpose
-     * and is used to generated [[rawSql]]. Do not modify it directly.
+     * and is used to generate [[rawSql]]. Do not modify it directly.
      */
     public $params = [];
     /**

framework/db/Connection.php

@@ -700,6 +700,31 @@ class Connection extends Component
     }
 
     /**
+     * Executes the provided callback by using the master connection.
+     *
+     * This method is provided so that you can temporarily force using the master connection to perform
+     * DB operations. For example,
+     *
+     * ```php
+     * $result = $db->useMaster(function ($db) {
+     *     return $db->createCommand('SELECT * FROM user LIMIT 1')->queryOne();
+     * });
+     * ```
+     *
+     * @param callable $callback a PHP callable to be executed by this method. Its signature is
+     * `function ($db)`. Its return value will be returned by this method.
+     * @return mixed the return value of the callback
+     */
+    public function useMaster(callable $callback)
+    {
+        $enableSlave = $this->enableSlave;
+        $this->enableSlave = false;
+        $result = call_user_func($callback, $this);
+        $this->enableSlave = $enableSlave;
+        return $result;
+    }
+
+    /**
      * Selects a slave and opens the connection.
      * @param array $slaves the list of candidate slave configurations
      * @return Connection the opened slave connection, or null if no slave is available

framework/db/oci/QueryBuilder.php

@@ -8,6 +8,7 @@
 namespace yii\db\oci;
 
 use yii\base\InvalidParamException;
+use yii\db\Connection;
 
 /**
  * QueryBuilder is the query builder for Oracle databases.
@@ -133,11 +134,9 @@ EOD;
             $value = (int) $value;
         } else {
             // use master connection to get the biggest PK value
-            $enableSlave = $this->db->enableSlave;
-            $this->db->enableSlave = false;
-            $value = (int) $this->db->createCommand("SELECT MAX(\"{$tableSchema->primaryKey}\") FROM \"{$tableSchema->name}\"")->queryScalar();
-            $this->db->enableSlave = $enableSlave;
-            $value++;
+            $value = $this->db->useMaster(function (Connection $db) use ($tableSchema) {
+                return $db->createCommand("SELECT MAX(\"{$tableSchema->primaryKey}\") FROM \"{$tableSchema->name}\"")->queryScalar();
+            }) + 1;
         }
 
         return "DROP SEQUENCE \"{$tableSchema->name}_SEQ\";"

framework/db/oci/Schema.php

@@ -8,6 +8,7 @@
 namespace yii\db\oci;
 
 use yii\base\InvalidCallException;
+use yii\db\Connection;
 use yii\db\TableSchema;
 use yii\db\ColumnSchema;
 
@@ -196,11 +197,9 @@ EOD;
     {
         if ($this->db->isActive) {
             // get the last insert id from the master connection
-            $enableSlave = $this->db->enableSlave;
-            $this->db->enableSlave = false;
-            $id = $this->db->createCommand("SELECT {$sequenceName}.CURRVAL FROM DUAL")->queryScalar();
-            $this->db->enableSlave = $enableSlave;
-            return $id;
+            return $this->db->useMaster(function (Connection $db) use ($sequenceName) {
+                return $db->createCommand("SELECT {$sequenceName}.CURRVAL FROM DUAL")->queryScalar();
+            });
         } else {
             throw new InvalidCallException('DB Connection is not active.');
         }

framework/db/sqlite/QueryBuilder.php

@@ -7,6 +7,7 @@
 
 namespace yii\db\sqlite;
 
+use yii\db\Connection;
 use yii\db\Exception;
 use yii\base\InvalidParamException;
 use yii\base\NotSupportedException;
@@ -120,10 +121,9 @@ class QueryBuilder extends \yii\db\QueryBuilder
             if ($value === null) {
                 $key = reset($table->primaryKey);
                 $tableName = $db->quoteTableName($tableName);
-                $enableSlave = $this->db->enableSlave;
-                $this->db->enableSlave = false;
-                $value = $db->createCommand("SELECT MAX('$key') FROM $tableName")->queryScalar();
-                $this->db->enableSlave = $enableSlave;
+                $value = $this->db->useMaster(function (Connection $db) use ($key, $tableName) {
+                    return $db->createCommand("SELECT MAX('$key') FROM $tableName")->queryScalar();
+                });
             } else {
                 $value = (int) $value - 1;
             }