Problems with developing dynamic websites using php-PHP + MySQL + Dreamweaver

I use the software is php-5.6.5, mysql-5.6.22, apache2.4, dreamweaverCS6, the operating system of course is windows8.1. I developed a webpage to read data from the database to the table. the specific steps are as follows. After you finish previewing by F12, the read content can also appear on the page, but the page header displays Deprecated: mysql_pconnect (): Themysqlextensionisdeprecatedandwillberemovedinthefuture: use... php dynamic webpage dreamweaver

The software I use is php-5.6.5, mysql-5.6.22, apache2.4, dreamweaverCS6, operating system of course
It is windows8.1. I developed a webpage to read data from the database to the table. the specific steps are as follows. After completion, press F12 to preview. the read content can also appear on the page, but the page header appears.
Deprecated: mysql_pconnect (): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in D: \ ProgramFiles \ PHP \ Apache24 \ htdocs \ phpweb \ Connections \ webconn. php on line 9
What are the reasons? How Can I disable the above content? Thank you!