PHP Yii Complex SQL

Yii allows developers to construct SQL statement.
This will help advanced developer to tune his/her SQL query (by using appropriate indexes).


Example:
$connection=Yii::app()->db;

$sql = "SELECT t1.colA, t2.colB, t3.colC, t3.colD 
           FROM tableA t1 
           LEFT JOIN tableB t2 ON t1.id=t2.id 
           LEFT JOIN tableC t3 ON t2.pid=t3.pid
           WHERE t1.id BETWEEN 10 AND 100 
           ORDER BY t1.modifyDate DESC";
$command = $connection->createCommand($sql);
$dataReader = $command->query();
$result = $dataReader->readAll();


Internal:
$command=createCommand($query)
Note: $command is a CDbCommand
|- $dataReader = query()
   Note: $dataReader is a CDbDataReader
   |- CDBDataReader->readAll() returns array()

PHP Yii ActiveRecord FindAllBySql()

Definition:
public array findAllBySql(string $sql, array $params=array ( ))
(refer http://www.yiiframework.com/doc/api/1.1/CActiveRecord#findAllBySql-detail)


Explanation:
Find all active records using specified SQL statement


Example:
1. $model = MyModel::model()->findAllBySql('SELECT colA, colB FROM any_table');
2. $model = MyModel::model()->findAllBySql($sqlString);
3. $model = MyModel::model()->findAllBySql('SELECT * FROM any_table WHERE colA=:param', array(':param'=>$value));


Internal:

findAllBySql($sql, $param)
|-$command = createSqlCommand($sql,$params)
  Note: $command is a CDbCommand
  |-populateRecords($command->queryAll())

PHP Yii ActiveRecord FindAllByPk()

Definition:
public array findAllByPk(mixed $pk, mixed $condition='', array $params=array ( ))
(refer http://www.yiiframework.com/doc/api/1.1/CActiveRecord#findAllByPk-detail)


Explanation:
Find all active records with specified primary key


$pk can be either 
1. string -> single-key primary key
2. array  -> single-composite-key primary key
(refer createPkCriteria in yii\framework\db\schema\CDbCommandBuilder.php)


Example:
1. $model = MyModel::model()->findAllByPk($id);
2. $model = MyModel::model()->findAllByPk(array('pkCol1'=>$col1, 'pkCol2'=>$col2));


Internal:

findAllByPk($pk, $condition, $param)
|-$criteria = createPkCriteria($this->getTableSchema(),$pk,$condition,$params,$prefix)
  Note: $criteria is a CDbCriteria
  |-query($criteria, TRUE)
    Note: TRUE means select all active records

PHP Yii ActiveRecord findAllByAttributes()

Definition:
public array findAllByAttributes(array $attributes, mixed $condition='', array $params=array ( ))
(refer http://www.yiiframework.com/doc/api/1.1/CActiveRecord#findAllByAttributes-detail)


Explanation:
Finds all active records that have specific attribute values


Example:
1. $model = MyModel::model()->findAllByAttributes(array('id'=>1, 'colA'='mystring'));
2. $model = MyModel::model()->findAllByAttributes(array('id'=>1, 'colA'='mystring'), "colB='mystring2'");
3. $model = MyModel::model()->findAllByAttributes(array('id'=>1, 'colA'='mystring'), "colB=:param", array(":param"=>'mystring2'));


Internal:

findAllByAttributes($attribute, $condition, $param)
|-$criteria = createColumnCriteria($this->getTableSchema(), $attributes, $condition, $param, $prefix)
  Note: $criteria is a CDbCriteria
           $prefix is defaulted to NULL. When calling findAllByAttributes, this function will not pass in $prefix. Therefore, in this case, $prefix is always NULL.
  |-query($criteria, TRUE)

PHP Yii ActiveRecord FindAll()

Definition:
public array findAll(mixed $condition='', array $params=array ( ))
(refer http://www.yiiframework.com/doc/api/1.1/CActiveRecord#findAll-detail)


Explanation:
Find all active records that satisfy specific conditions
findAll() returns array instead of CAtiveRecord


Example:
1. $model = MyModel::model()->findAll("id=1");



Internal:

please refer find() for explanation of $condition.

findAll($condition, $param)

|-$criteria = createCriteria($condition, $param)

  > Note: $criteria is a CDbCriteria

  |-query($criteria, TRUE)

  Note: TRUE has been passed in so that system will retrieve all active records

(refer yii\framework\db\ar\CActiveRecord.php)

PHP Yii ActiveRecord Find()

Definition:

public CActiveRecord find(mixed $condition='', array $params=array ( ))

(refer http://www.yiiframework.com/doc/api/1.1/CActiveRecord#find-detail)

Explanation:

Find a single active record with specified conditions

Always return first record in the result set

$condition can be either

1. array

2. CDbCriteria

3. string

When $condition is an array, CDbCriteria class will map each key to predefined field name. Below is a list of predefined field name:

a. $select [default = '*']

b. $distinct [default = FALSE]

c. $condition [default = '']

d. $param [default = array()]

e. $limit [default = -1]

f. $offset [default = -1]

g. $order [default = '']

h. $group [default = '']

i. $join [default = '']

j. $having [default = '']

k. $with - alias of the table name [default = 't']
l. others - $alias, $together, $index, and $scopes

When $condition is a string, system will map it to CDbCriteria->$condition (item c above)

Example:

1. $model = MyModel::model()->find("id=1");

2. $model = MyModel::model()->find("id={$id}");

3. $model = MyModel::model()->find("value='mystring'");

4. $model = MyModel::model()->find("value='{$mystring}'");

5. $model = MyModel::model()->find("id=1 ORDER BY colA ASC");

6. $model = MyModel::model()->find("id=:param", array(":param"=>1));

7. $model = MyModel::model()->find("id=:param1 AND colA=:param2", array(":param1"=>1, ":param2"=>'mystring'));
8. $model = MyModel::model()->find(array('select'=>'colA', 'condition'=>'id=1', 'order'=>'colB DESC'));

Internal:

find($condition, $param)

|-$criteria = createCriteria($condition, $param)

  Note: $criteria is a CDbCriteria

  |-query($criteria, FALSE)

    Note: FALSE means add "LIMIT 1" to SELECT statement

(refer yii\framework\db\ar\CActiveRecord.php)