Reading Record from database in yii

// find the first row satisfying the specified condition
$post=Post::model()->find($condition,$params);
// find the row with the specified primary key
$post=Post::model()->findByPk($postID,$condition,$params);
// find the row with the specified attribute values
$post=Post::model()->findByAttributes($attributes,$condition,$params);
// find the first row using the specified SQL statement
$post=Post::model()->findBySql($sql,$params);