How can I make "KE" see my linked database statements?

How can I avoid "black KE" seeing my linked database statements ?!! The younger brother is learning PHP. basically every page is required. some of them are included in inclue, but those who know PHP network can see the importance of such information at a glance, so how can we avoid being seen by criminals efficiently and easily? Please enlighten me! $ Db = mysql_connect (& quot; AAA & q How can I avoid "black KE" from seeing my linked database statements ?!!
The younger brother is learning PHP. basically every page is required. some of them are included in inclue, but those who know PHP network can see the importance of such information at a glance, so how can we avoid being seen by criminals efficiently and easily? Please enlighten me!

$ Db = mysql_connect ("AAA", "BBB", "CCC ");
$ Sqlname = "BBB ";
Mysql_select_db ($ sqlname, $ db) or die ("database error! ");
Mysql_query ("set names 'utf8'", $ db );

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Discussion

That is, the data is deleted and some hacker information is put. The guy seems to be outside China, showing off his many cool bits!

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Outside China? Understanding. Give a link.

Serious: SQL injection attacks. Didn't the database be processed before?
Go to Google to search for "php anti-SQL injection"