PHP class constructor , how to initalize pictuer “blob” type?
I have class and I want to initalize column that stores pictuer with type "blob" but I'm not sure how? take a look at the lat line of the code 
    public function __construct( $data=array() ) {


    if ( isset( $data['id'] ) ) $this->id = (int) $data['id'];
    if ( isset( $data['date'] ) ) $this->date= (int) $data['date'];
    if ( isset( $data['topic'] ) ) $this->topic = preg_replace ( "/[^\.\,\-\_\'\"\@\?\!\:\$ a-zA-Z0-9()]/", "", $data['topic'] );
    if ( isset( $data['author'] ) ) $this->author = preg_replace ( "/[^\.\,\-\_\'\"\@\?\!\:\$ a-zA-Z0-9()]/", "", $data['author'] );
    if ( isset( $data['content'] ) ) $this->content = $data['content'];
    if ( isset( $data['picture'] ) ) $this->picture ="Here sholud be the Type" $data['picture'];
    }
PHP class constructor , how to initalize pictuer “blob” type?
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I have class and I want to initalize column that stores pictuer with type "blob" but I'm not sure how? take a look at the lat line of the code 
    public function __construct( $data=array() ) {


    if ( isset( $data['id'] ) ) $this->id = (int) $data['id'];
    if ( isset( $data['date'] ) ) $this->date= (int) $data['date'];
    if ( isset( $data['topic'] ) ) $this->topic = preg_replace ( "/[^\.\,\-\_\'\"\@\?\!\:\$ a-zA-Z0-9()]/", "", $data['topic'] );
    if ( isset( $data['author'] ) ) $this->author = preg_replace ( "/[^\.\,\-\_\'\"\@\?\!\:\$ a-zA-Z0-9()]/", "", $data['author'] );
    if ( isset( $data['content'] ) ) $this->content = $data['content'];
    if ( isset( $data['picture'] ) ) $this->picture ="Here sholud be the Type" $data['picture'];
    }