db\ActiveRecordInterface findOne()

Returns a single active record model instance by a primary key or an array of column values.

The method accepts:

• a scalar value (integer or string): query by a single primary key value and return the corresponding record (or null if not found).
• a non-associative array: query by a list of primary key values and return the first record (or null if not found).
• an associative array of name-value pairs: query by a set of attribute values and return a single record matching all of them (or null if not found). Note that ['id' => 1, 2] is treated as a non-associative array.

That this method will automatically call the one() method and return an ActiveRecord instance. For example,

// find a single customer whose primary key value is 10
$customer = Customer::findOne(10);

// the above code is equivalent to:
$customer = Customer::find()->where(['id' => 10])->one();

// find the first customer whose age is 30 and whose status is 1
$customer = Customer::findOne(['age' => 30, 'status' => 1]);

// the above code is equivalent to:
$customer = Customer::find()->where(['age' => 30, 'status' => 1])->one();