safeDown() public method This method contains the logic to be executed when removing this migration. This method differs from down() in that the DB logic implemented here will be enclosed within a DB transaction. Child classes may implement this method instead of down() if the DB logic needs to be within a transaction. public boolean safeDown ( )return boolean Return a false value to indicate the migration fails and should not proceed further. All other return values mean the migration s

loadColumnSchema() protected method Loads the column information into a yii\db\ColumnSchema object. protected yii\db\ColumnSchema loadColumnSchema ( $info )$info array Column information return yii\db\ColumnSchema The column schema object

addCommentOnColumn() public method (available since version 2.0.8) Builds a SQL command for adding comment to column public string addCommentOnColumn ( $table, $column, $comment )$table string The table whose column is to be commented. The table name will be properly quoted by the method. $column string The name of the column to be commented. The column name will be properly quoted by the method. $comment string The text of the comment to be added. The comment will be properly quoted

read() public method Advances the reader to the next row in a result set. public array read ( )return array The current row, false if no more row available

$module public property public yii\debug\Module $module = null

getDetail() public method public string getDetail ( )return string Content that is displayed in debugger detail view

defaultExpression() public method (available since version 2.0.7) Specify the default SQL expression for the column. public $this defaultExpression ( $default )$default string The default value expression.

query() public method Executes the SQL statement and returns query result. This method is for executing a SQL query that returns result set, such as SELECT. public yii\db\DataReader query ( )return yii\db\DataReader The reader object for fetching the query result throws yii\db\Exception execution failed

confirm() public method Asks user to confirm by typing y or n. public boolean confirm ( $message, $default = false )$message string To echo out before waiting for user input $default boolean This value is returned if no selection is made. return boolean Whether user confirmed. Will return true if $interactive is false.

$password public property The password for establishing DB connection. Defaults to null meaning no password to use. public string $password = null